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MARINE BIOLOGY VOLUME 6
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Advances in
MARINE BIOLOGY VOLUME 6
This Page Intentionally Left Blank
Advances in
MARINE BIOLOGY VOLUME 6 Edited by
SIR FREDERICK S. RUSSELL Plymouth, England
and
SIR MAURICE YONGE Edinburgh, Scotland
Academic Press London and New York
1968
ACADEMIC
PRESS INC. (LONDON) LTD.
BERKELEY
.----.?. L
/ti
/ "
-
'
SQUARE HOUSE
BERKELEY
SQUARE
LONDON, W l X 6BA
U.S. Edition published by ACADEMIC PRESS INC.
111
FIFTH AVENUE
NEW YORK, NEW YORK
10003
Copyright 0 1968 by Academic Press Inc. (London) Ltd.
All rights reserved
NO PART OF THIS BOOK MAY BE REPRODUCED IN ANY FORM B Y PHOTOSTAT, MICROFILM, OR ANY OTHER MEANS, WITHOUT WRITTEN PERMISSION FROM THE PUBLISHERS
Library of Congress Catalog Card Number: 6 3 - 1 4 0 4 0
PRINTED I N GREAT BRITAIN B Y THE WHITEFRIARS LONDON AND TONBRIDOE
PRESS LTD.
CONTRIBUTORS TO VOLUME 6 J. E. CARROZ, Legislation Research Branch, Department of Relations and Legal Affairs, F.A.O., Rome, Italy. .
Public
E. GHIRARDELLI, Istituto d i Zoologia oe Anatomia Gomparata della Universita d i Trieste, Ituly.
J. A. GULLAND, Department of Fisheries, F.A.O., Rome, Italy. W. MACNAE, Department of Zoology, University of the Witwatersrand, Johannesburg,South Africa.
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CONTENTS
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v
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1
11. The Need for Management . . .. .. A. The Depletion of Marine Resources. . B. Theoretical Studies . . .. ..
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16
111. Methods of Regulation .. .. .. A. Types of Regulation . . .. .. B. Limitation of the Amount of Fishing
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29
The Mechanics of Management and InternationalLaw . . A. Territorial Sea and Fishing Zones . . .. .. B. Specialized Fishery Bodies . . .. .. ..
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45
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CONTRIBUTORSTO VOLUME6
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of Fishery Resources
Management
J. A. GULLAND and J. E. CARROZ
I. Introduction . .
IV.
V.
VI.
VII.
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Problems and Prospects for FutureProgress A. Achievements of Present Bodies .. B. The Need for FurtherResearch .. C. InternationalManagement . . ..
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35
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45 50 53
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56
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56
Appendix : Table of InternationalBodies Concerned with .. .. .. .. .. Fishery Management
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Acknowledgements . . References
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vii
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CONTENTS
Vlll
A General Account of t h e Fauna and Flora of Mangrove Swamps and Forests i n t h e Indo-West-Pacific Region WILLIAMMACNAE
I. Introduction . . .. .. .. A. The Word “Mangrove” .. B. Early Historical References . . C. Indo-west-Pacific Shores .. D. Sea-shore Plant Associations. .
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75 77
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115
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.. .. .. 111. Adaptations Shown by the Flora . . A. Adaptations to Growing in Ill-consolidated Muds. B. Specializations of Stems and Leaves .. ..
136
11. Zonation of Mangroves .. .. A. The Landward Fringe .. .. B. Zone of Ceriops Thickets C. Zone of Bruguiera Forests . . D. Zones of Rhizophora Forests E. Seaward Avicennia Fringes . . F . SonneratiaZone .. .. G. Variations .. .. .. H. Mangrove Soils .. .. I. Control of Zonation . . ..
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.
76
91 103 105
118 121 124
136 140
C. Relationship between the Mangrove Root and Shoot .. .. . . 144 Systems .. .. .. .. .. . . 145 D. Viviparity .. .. .. .. .. . . 148 E. Succession .. .. .. IV. Distribution of Terrestrial Animals within the Mangal. . A. Birds Associated with Mangals .. .. .. B. Amphibians and Reptiles . . .. .. ..
C. Mammals D. Insects . .
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150 153 156 157 157
ix
CONTENTS
V.
VI.
Distribution of Marine Animals within the Mangal . . 165 A. Vertical Zonation Affecting Tree Dwelling Animals 165 B. “Horizontal” Zonation through the Mangal . . 167 Specializations Shown by the Fauna .. .. A. Birds, Mammals, Reptiles and Amphibians B. Insects . . .. .. .. .. .. C. Marine Animals .. .. .. ..
., .
181 181
I
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182
.,
184
VII. Geographical Distribution . . .. .. .. ., 219 A. Extratropical Extensions of Mangroves and their Associated Fauna . . . . .. .. . . 219 B. Biogeographical Comment . . .. .. . . 222
VIII. Uses Made by Man of the Mangal and its Products A. Uses of the Timber . . .. .. .. B. Pond Culture of Fish and Prawns . . .. C. Reclamation . . .. .. .. .. D. Salt Production .. .. .. ..
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233 233
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. . 238 . . 240
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241
X. Bibliography and References
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241
IX. Acknowledgements . .
Some Aspects of the Biology of the Chaetognaths ELVEZIOGHIRARDELLI
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271
11. General Morphology. . .. .. A. The Eyes, Hooks and Teeth . . B. Integument, Fins and Tail . . C. Corona ciliata . . .. ..
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I. Introduction . .
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273 274 281 .1
X
COXTEXTS
111. Reproduction. . .. .. .. .. .. A. The Male Genital Apparatus. . .. .. B. The Female Reproductive Apparatus. General .. C. Spermatogenesisand Oogenesis .. .. D. Fertilization . . .. .. .. .. E. Laying of Eggs .. .. .. F. Habitat and Cycles of Sexual Maturity . . IV. V.
Regeneration . .
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289
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289 292 309 322 335 343
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. . 351
Affinities and Systematic Position . .
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VI. Laboratory Experiments VII, Acknowledgements . .
*
355
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. . 365
364
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. . 366
AUTHORINDEX . .
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. . 377
TAXONOMIC INDEX ..
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. . 395
VIII. References
SUBJECTINDEX
Adv. mar. B i d , Vol. 6, 1968, pp. 1-71
MANAGEMENT OF FISHERY RESOURCES* J. A. CULLAND? Department of Fisheries, F.A.O., Rome, Italy and
J. E. CARROZ Legislation Research Bran,ch, Department of Public Relations and Legal Affairs, F.A.O., Eome, Italy I. Introduction .. .. .. .. .. .. .. 11. The Need for Management .. .. .. .. .. A. The Depletion of Marine Kesources .. .. R. Theoretical Studies . . .. .. .. .. 111. Methods of Regulation . . .. .. .. .. .. 4 .. Types of Regulation . . . . .. .. .. B. Limitation of the Amount of Fishing .. .. IV. The Mechanics of Management and InternationalLaw .. A. Territorial Sea and Fishing Zones . . . . .. R. Specialized Fishery Bodies . . .. .. .. V. Problems and Prospects for Future Progress .. .. A. Achievements of Present Bodies . . .. .. B. The Need for FurtherResearch .. .. .. C. InternationalManagement . . . . .. .. VI. Acknowledgements .. .. .. .. .. .. VII. Roferences .. .. .. .. .. .. .. Appendix: Table of International Bodies Concerned with Management . . . . .. .. .. .. ..
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I
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1 7 7 16 25 25 29 34 35 39 45 45 50 53 56 56
Fishery
..
..
62
I. INTRODUCTION The estimated world production of fish has more than doubled in the last two decades, from less than 20 million metric tons in 1948 to over 50 million tons in 1965 (see Table I ;F.A.O., 1966a). This increase, which is considerably faster than the increase of either the human population or the production of food as a whole, means that fish are making an increasingly important contribution to the world's food supply, particularly of animal protein. In the world as a whole, fish * This paper was first published, undcr the same title, as Chapter I V in "The State of Food and Agriculture 1967 "(F.A.O., Rome, 1967). Some changes have been made from the original version, principally in order to make the presentation more suitable for a scientific audience. I n so far as there are differences from tho earlier publication, these represent the views of the authors and are not necessarily those of the F.A.O. Formerly of the Fisheries Laboratory, Lowestuft, England. 1
2
J. A . GULLAND A N D J. E. CARROZ
contribute about 10% of the total animal protein intake, but con siderably more in some areas such as the Far East (see Table 11). While a n increasing proportion of the total catch is not used directly for human consumption but is converted to fish meal, this fish is used for producing human food in commercially more attractive forms by feeding it to chicken, trout, etc. ; recent developments in marine fish culture suggest that in the future further supplies of fish meal will be needed to produce valuable marine fish such as plaice (Pleuronectes platessa L.), sole (Solea solea (L.)) or yellowtail (Xeriola quinqueradiata (Temminck & Schlegel)) (Shelbourne, 1964), or shellfish such as prawns or lobster. The increased catches, due both to increased local fishing and especially the rapidly increasing number of mobile factory and other vessels operating far from their home bases, have intensified the TABLEIA. WORLDFISH PRODUCTION, 1948-65 Million metric tons live weight. (FromF.A.O., 1966a.)
Total world production:.
.
Africa . North America South America Asia . . Europe . Oceania . U.S.S.R. .
.
1948
1958
1960
1962
1963
1964
1965
19.6
32.8
39.5
46.4
47.6
52.0
52.4
2.6 4.5 8.3 18.6 8.7 0.1 3.6
2.7 4.4 8.4 19.0 9.0 0.1 4.0
3.0 4.3 11.0 19.3 9.7 0.2 4.5
3.1 4.4 9.0 19.9 10.8 0.2 5.0
6.4 29.0 3.5 0.6
6.5 35.3 3.8 0.8
6.7 36.1 4.1 0.7
6.8 40.7 3.8 0.7
7.2 40.4 4.1 0.7
17.5 5.7 8.1 4.8 15.3 1.0
Continent (region)
.
.
. .
. .
. .
1.0 3.6 0.5 6.8 6-1 0.1 1.5
2.1 4.0 1.6 14.6 7.8 0.1 2.6
2.3 4.1 4.4 17.4 8.1 0.1 3.1
Group of species Vrcshwatcr fishes. . 2.5 Marine fishes . . 14.7 Crustaceans, molluscs . . 2.0 Other aquatic animalsand plants 0.4
5.4 23.9 2.9 0.6
Utilization Human consumption Fresh . Breezing . Curing . Canning . Other purposes Reduction . Miscellaneous .
.
14.5 2-7 7.3 3.0
16.3 3.4 7.5 3.7
16.9 4.3 8.1 4.1
17.3 4.7
.
9.7 1.0 5.0 1.4
4.1
17.6 5.1 8.4 4.4
.
1.5
.
1.0
4.3 1.0
7.6 1.0
12.0 1.0
12.0 1.0
15.5 1.0
. ,
8.5
3
MANAGEMENT O F BTSHERY RESOllRCES
TABLEIB. MARINEFISHES PRODUCTION, 1948-65 Million metric tons livc weight. (FromF.A.O., 1966a.) 1948
1958
1960
1962
1963
1964
1965
14.7
23.9
29.0
35.3
36.1
40.7
40.4
Species 0.5 0.8 3.6 4.5 1.2 2.2 0.5 1.8 4.7 7.4 0.4 1.0 0.6 1.0 0.3 0.3 2.9 4.9
1.2 5.0 2.4 1.7 10.2 1.0 1.1 0.4 6.0
1.2 5.5 2.6 2.1 14.8 1.2 1.1 0.4 6.4
1.0 5.9 2.7 1.9 15.1 1.2 1.2 0.4 6.7
1.0 6.0 2.9 2.0 18.7 1.2 1.4 0.4 7.1
1.0 6.5 3-0 2.1 17.4 1.2 1-7 0.4 7.1
Principal marine fishing areas 8.0 9.1 9.8 10.3 North Atlantic . . 5.1 2.2 3.4 4.3 Central and South Atlantic . 0.8 0.7 0.8 0.8 MeditcrraneanandBlackSeas 1.7 1.5 1.8 Indian Occan . . 1.0 4.1 4.6 3.7 2.5 North Pacific . . 3.1 8.2 8.8 9.9 Contra1Pacific . 7.7 0.2 1.3 4.0 South Pacific . .
10.9 5.2 0.9 1.7 4-5 10.2 7.8
11.5 5.6 1.0 1.9 4.9 10.0 10.5
12.7 6.2 0.9 1.9
Total marine fishes:
.
.
Flounders,halibuts, soles . Cods, hakcs, haddocks . . Redfish, basses, congers . Jacks, mullcts . . Herrings, sardines, anchovies. Tunas, bonitos, skipjacks . Mackerels . . . Sharks, rays . . Unsorted and other . .
.
5-4 10.3 8.4
problems of overfishing, and the possible need of regulations and management t o make the best use of the resources. At the time of the 1949 U.N. Scientific Conference on the Conservation and Utilization of Resources a t Lake Success, the only overfished stocks were a limited number of stocks of high-priced species, mainly in the North Atlantic and North Pacific (e.g. the plaice in the North Sea, the halibut and salmon in the north-east Pacific), and the Conference drew up a map showing some thirty stocks then believed t o be underfished (see Fig. 1). Of these stocks about half are now probably in need of proper management, including the cod (Gadus morhua L.), redfish (Sebastes spp.) and herring (Clupea harengus L.) in the North Atlantic, and a t least some species of tunas in most of the oceans. The classical response of the fishing industry t o overfishing in one stock has been to move to other, usually more distant stocks, but it is clear that this process cannot continue much longer. Some blank spaces in the Lake Success map have been filled by more recently discovered resources, e.g. oil sardine (Xardinella spp.) and Rastrelliger spp. in the Arabian Sea, or hake (Merlucciusspp.) off the west coasts of the Americas, but it is significant
15'
5 0'
45" 3 On 15O O0 15O
3 On
4 !I0 6 On I
I
150"
I
I
12O0
,
I
gon
1
I
6 0"
I
I
3 '0
I
I
Do
I
I
3 0"
I
I
6 0"
I
I
90n
I
1
120'
I
I
150"
I
I
I
180n
FIG. 1. Map showing latent marine fishery resources (fish stocks believed to be underfished in 1949). Circled stocks are those now certainly or probably in need of management (the "pilchard " off the west coast of South America presumably refers to the anchoveta stock). Of the tunas, the yellowfin is probably heavily exploited in all areas, but further expansion may be possible for other species such as skipjack or bonito. (From United Nations, 1931.)
5
MANAGEMENT O F FISHERY RESOURCES
TABLE11. PER CAPUT PROTEIN SUPPLIES, BY REGION(RECENT PERIOD) Prom "State of Food and Agriculture 1964 ",F.A.O. Rome.
Fish
Anirnal protein -~
Total protein
Region
~
-~
U.S.S.R.
.
North Amorica. . Oceania . Latin Amorica . . Far East (incl. mainland China) . . Near East . Africa . High-calorie countries* Low-calorie countricst
.
_.________
As "/b of A s yo of total Total total protein protein ( g per caput per day)
A s yo of animal protein
~____
_ _
~~~~
Wcsterri Europe . Eastern Europe and
World
Total
-
.
83
39
47
2.4
2.9
6.2
.
94 93 94 67
33 66 62 24
35 71 66 36
1.9 2.5 2.2 1.5
2.0 2.7 2.3 2.2
5.8 3.8 3.5 6.3
56 76
8 14
14 18
2.2 1.1
3.9 1.4
27.5 7.9
.
61 90 58
11 44 9
18
.
49 16
1.3 2.4 1.9
2.1 2.7 3.3
11.8 5.5 21.1
.
68
20
29
2.3
3.4
11.5
. f
.
. . .
* Europe, North America,
Oceania, Hiver Plate countries.
?- Latin America, P a r East and Near East, Africa.
that these additions have been in the areas (IndianOcean, south-east Pacific) away from the old centres of fishery development, and no major new resources have been discovered in the North Atlantic, or north-west Pacific. At the present rate of development few substantial unexploited stocks of fish accessible to the present types of gear will remain in another twenty years. Thus the problem of international management is becoming increasingly urgent. This problem is not confined t o the high seas, but occurs also in inland waters, especially in the larger rivers and lakes where the biological problems are essentially the same as in the sea, even though the problems of international fishing may be much less. For certain stocks which are particularly vulnerable, e.g. salmon going upstream to spawn, the problems of overfishing may become more intensive than in any purely marine fishery. Inlandwaters also present other problems, such as pollution, and the alternative use of water resources-power, irrigation etc.-which may conflict with fisheries. These are less pressing in the sea, though there are similar problems, for instance the use of the other resources of the sea-bed such as minerals or oil, which
6
J. A. GULLAND AND J. E. CARROZ
may also conflict with fisheries. However, these problems will not be considered further here; nor will this article be concerned with the problems of fish culture in ponds, brackish water or enclosed parts of the sea, except that such culture may have an indirect effect on the open water fisheries by increasing the demand for cheap supplies of food for the choicer varieties of fish being farmed. The problems of overfishing arise because, in default of definite arrangements, the fishery resources are not the responsibility of any single person or body. Next year’s catches depend on how much is taken this year, but in the open sea the individual fisherman can do little to ensure better fishing for himself next year-if lie does not catch fish while he can, someone else will catch them. Thus effective management depends on the participation of all, or at least of the great majority, of those exploiting a given stock of fish. The problems are more complex when many countries are concerned or when more than one species of fish is caught (especially when there may be biological interactions between the stocks, e.g. one species being the main food of another),but the main problems are essentially the same even when a single stock is exploited by a single country. The first problem is biological: t o understand the population dynamics of the stock or stocks concerned, and thus make quantitative assessments of the probable effect on the stocks and on future catches of any regulatory measure. Until this biological understanding is available, it is unrealistic to consider the other problems of regulation, though at first the biological study need not be very intense. A simple study may show that a stock is in urgent need of regulation, and any effective measure would be bound to improve matters; only as the first measures take effect will more detailed biological data be needed to determine the precise needs for further measures. Too often conservation measures have been delayed, and great damage done to the stock and the fishery on it by the demand for complete and conclusive biological evidence; the final conclusive proof that a stock is being depleted is when it becomes extinct. Biological considerations are, of course, only the first step; the aim of fishery management is not primarily to maintain the stocks of fish, but to make the best use of the resources in terms of larger or cheaper supplies of fish to the consumer, better income to the fishermen, etc. The desired result of regulation, especially when the objective is t o take about the same catch more cheaply, can therefore only be ensured by taking into account the probable economic and other non-biological effects of proposed regulation. Economic and similar considerations will also become increasingly important in resolving disputes between
MANAGEMENT O F FISHERY RESOURCES
7
groups of fishermen with conflicting interests, e.g. one group fishing herring and another group taking cod which feed on herring. However, problems of management, and indeed some of the outstanding examples of the failure to achieve proper management, have occurred when there has been no conflict of long-term interests, but merely a conflict between the long-term interest for the fishery as a whole and the immediate desire of the individual fisherman to catch as much as he can today. It is natural not to be greatly concerned with a problem until it becomes urgent; thus so long as most fish stocks were not too heavily fished, and there remained alternative unexploited stocks t o which the fleets exploiting the overfished stocks could turn, the problems of fishery management have received too little attention. This is particularly unfortunate because of the need, from several considerations, to take action as early as possible. Biologically, the assessment of any fishery depends on measuring the effect on the stock of changes in fishing. This assessment is made much easier and more precise if data are available from periods of very light fishing. Detailed and expensive biological studies of the stocks after the fishery has become very intense cannot substitute for reliable data on such simple things as the average size of fish, or the average catch per boat, from the periods of light fishing. Similarly, the practical problems of regulations are much less if regulatory measures are considered well before the stocks are clearly overfished ;the social problems in limiting further entry t o a fishery are much less than those in reducing the existing number of boats or number of fishermen. For all these reasons, therefore, the various problems relating to proper management of fishery resources deserve urgent attention.
11. THENEEDFOR MANAGEMENT A. The depletion of marine resources A hundred years ago most people, including leading scientists, believed that the living resources of the sea were essentially inexhaustible-" there are more good fish in the sea than ever came out of i t ". K,epeated experience since then, a t first for the most valuable or vulnerable species, has shown how false this assumption was. The first stocks to show depletion were those close to the ports of the industrial nations. Shortly after the development of the steam trawler-one of the earliest applications of modern industrial techniques to fishing-the stocks of plaice in the North Sea showed signs of depletion. The average annual landings of plaice by individual trawling smacks was clearly decreasing as early as 1880, even though the total landings were still
8
J. A . (:ULLAND A N D J.
E. CARROZ
increasing (Wimpenny, 1053). Convincing proof that this decline, and the decline in stocks of other valuable species, was due to fishing was provided by the severe restrictions on fishing during the two world wars. Immediately after each war the catches of the individual trawlers were several times the pre-war avesages (see Fig. 2) (Wimpenny, 1953 ; Margetts and Holt, 1948). Similar recoveries were noted in other stocks where the amount of fishing was greatly reduced, e.g. the haddock (Melanogrammus aegle,finus (L.)) in the North Sea and a t Faroes (Parrish and Jones, 1953), the hake (Merluccius mqrluccizcs L.) to the south-west of the British Isles (Hickling, 1946) and yellow sea bream (Taius tumifrons (Tanaka & Schlegel))in the East China Sea (Shindo, I -+
I
I
I
I
I
I
I
c L
-
920 -
200 - m
c c
I
c
r: g 1 5 2; -
'sc ma)
3s -a
9 P-4,
- 1 0 - tr
G -m c x 342 b
a
Q\
c
?, 5-
A ma L J
0
-50 I
I
I
I
I
a
1
1960). These and other similar changes show clearly not only how fish stocks can be depleted by fishing but also that the process is reversible. Thus with proper management stocaks can build up again, even such vulnerable stocks as whales ; for instance, the southern right whale (Eubalaena australis (Desm.)) is returning to Ncw Zealand waters (Gaskin, 1964), and the numbers of California gray whales, after having been very severely reduced by unrestricted catches, were given complete protection and have incrcased at around 10% per year-close to the rate for the Antarctic stocks of blue and fin whales calculated from their reproductive and mortality rates (Rice, 1961). Because of the difficulties, discwssed later, in achieving proper management of major mariiie resources, especially in international waters, there are far more examples of stocks declining in the absence of proper managements. One example of an important stock being
MANAGEMENT
O F FISHERY RESOVRCES
9
built up by regulation is the Pacific halibut. This large, long-lived and ecouomically valuable fish is particularly vulnerable to overfishing and by the 1920s the stocks had been severely depleted. As a result of conventions between the two countries concerned (U.S.A. and Canada) the amount of fishing in 1960 was about half w h a t it was in 1930; the stock has been increascd one- to threefold, and the catches have increased from a minimum of 43 million lb in 1931 to more than 65 million lb in 1960 (ChapmanP t al., 1962). The management of this stock has thus been highly successful in maintaining the stock and the catch, but the full benefits of management have not been achieved. Although the amount of fishing, in terms of the impact on the stock, has been halved, the costs have been nowhere near halved, since the number of ships operating has increased while the length of season has been very severely reduced. Both the catching and marketing side of the industry are therefore operating at a very low level of efficiency (Crutchfieldand Zellner, 1963). I n the absence of regulation and management of the over-exploited stocks, the response of the industries concerned has been to turn to other, more distant or less immediately attractive stocks. After the North Sea had shown itself to be capable of producing only limited quantities of the preferred species-cod, plaice, etc.-the fishing industries of the industrial nations, such as England and Germany, turned to the "distant water " grounds, especially Iceland and the Barents Sea. I n the North Sea, fishing was continued with the existing vessels which were not suitable for fishing the more distant grounds, and as these vessels were lost or scrapped without being replaced the level of exploitation in the North Sea by countries with interests on distant water fishing fell. Thus, even in 1050, virtually all the English North Sea trawlers then operating were built before 1925." As a result the level of fishing on the North Sea plaice stocks has recently been lower than a t any time (other than during the war periods) for the past eighty years ; this, combined with favourable natural conditions has provided record catches in 1964 (incidentally confirming the predictions, by Russell (1942), Bevcrton and Holt (1957) and others, based on the analysis of the heavily fished stocks of the 1930s, that a moderate decrease in the amount of fishing would give an increase in total catch) (Gulland,1967, 1968a). The catches of other iiiiportant demersal species (cod and haddock) have also been very high in recent years. These fish are caught by rather different groups of vessels from plaice, haddock
* VcsscIs of other countries, especially Uenmark, rrmained fishing in the North Sea but changed in part t o other stocks, such as hcrring or sand-eels.
10
J. A . GULLAND AND J. E. CARROZ
especially being a major interest to Scottish fishermen, and Scottish fishing has not expanded to distant waters to anything like the same extent as English fishing. Thus it is not clear whether the fishing on these species has declined to the same extent as the fishing on plaice though the cod stocks in the central North Sea seem to have also benefited from reduced fishing (M.A.F.F., U.K., 1962). Certainly the recent good catches have been due in part to outstanding year-classes, especially the 1962 haddock year-class (M.A.F.F., U.K., 1966). There may well have been a decrease in effort; also haddock catches in particular are likely t o have benefited from the larger mesh sizes introduced under the 1946 Overfishing Convention (I.C.E.S., 1957). The diversion of the main attention of some of the countries bordering the North Sea has therefore allowed some a t least of the North Sea demersal stocks to recover temporarily t o a level not far from the optimum. However, a t this level of fishing any increase in fishing would, in the long term, reduce the total catch. The recent success of North Sea fishing is attractingsome of the resources of ships and capital back to the North Sea, and without some restriction only a fraction of the resources a t present devoted to distant water fishing could quickly reduce the North Sea stocks again to the low level of the 1930s. Temporarily, though, some North Sea demersal stocks have benefited from diversion of fishing to other stocks, but these latter stocks have in their turn become depleted. The first of the distant water stocks to become depleted were the small but economically attractive stocks, such as the plaice off Iceland and in the Barents Sea; the abundanceof these stocks, as measured by the catch per hour, had been reduced as early as 1925 to a small fraction of their initial level. Russell (1942) and more recently Gulland (1961) describe clearly the decline in catch per hour of plaice and other species by English trawlers fishing a t Iceland, and the relation of this decline to the changes in the total amount of fishing. The larger cod stocks were able to support a greater total amount of fishing, but by the mid-1950s they too werc being heavily exploited. For instance, despite an increasein the amoufit of fishing since 1946 of several times (possibly as much as tenfold), the catches of cod from the Arcto-Norwegian stock (living in the waters between northNorway, Russia and Spitsbergen)has fluctuated between 600 000 and I 300 000 tons with no evidence of any increasing trend (see Fig. 3) (I.C.E.S., 1966). I n the last decade the further expansion of European fishing, including diversion of some of the effort formerly engaged in fishing the depleted stocks of the north-east Atlantic, and also increasing numbers of new freezer and factory trawlers (Fig. 4), especially from eastern
11
MANAGEMENT O F FISHERY RESOURCES
I400
m v1
0
t 0 c
7
x
c 0
v)
L
0 2
Cn
II:
D t
c + 0
500 0 L
+
d
Total effort d’
I
I
I
I
I
I
I
1930
35
40
115
50
55
60
0
FIG. 3. Arctic cod. 0-0, Total landings (in thousandsof tons); 0 - - - 0, total effort in English units (ton-hours x 10-8). (From I.C.E.S., 1966, Liaison Committee Report .)
FIG.4. The Ross Vanyuard, a modern British freozer trawler, capable of catching and freezing several hundred tons of fish during a 6-week voyage. (Photo: Pishinq News.)
Europe, has been directed to the north-west Atlantic, and more recently t o the centraI and southernAtlantic. Some of the stocks of the western Atlantic were already heavily fished by local fisheries, as well as by the long-established southern European fisheries for salt cod, but in the last few years some of the stocks, such as those off west Greenland,
12
J . A. GULLAX’IU A N D J . E. CARROZ
which until recently had been only lightly exploited, have become depleted (see the annual reports of the I.C.N.A.F. Assessment subCommittee in the I.C.N.A.F. Red Books ; Beverton and Hodder, 1962) (Figs. 5 an d 6). The exploitation of the pelagic species (particularlyherring)has not (up t o 1965) gone so far as tha t of the bottom-living cod, haddock, etc., but some of the local stocks of herring, such as those in the southern North Sea have been seriously depleted b y fishing, and lately there has been increasing concern about other herring stocks (see recent I.C.E.S. Liaison Committee reports). These events in the North Atlantic may be summarized in the form of a map showing the approximate date at which the fishing on each stock reached a level a t which further increase in the amount of fishing would give no appreciable increase in the sustained yield (see Fig. 7 ) . Most recently a major part of the expansion of Europeanfishing has been outside the North Atlantic, particularly off the west coast of Africa. Even as far away as off the roasts of South Africa and South West Africa by 1965 the country taking the biggest catch of hake (Merluccius cupensis Castlenau), the main bottom-living species, was
FIG. 5. The internationalfishing fleet on the Labrador Uanlrs. Trawlors from East Germany and Russia photographed from a British freezer trawler. (Photo: Fishing News.)
MANAGEMENT
O F FISHERY RESOURCES
13
FIG.6 . Why thc trawlers go t o Labrador;the cod-end of the trawl, with several tons of fish, comes on board a freezer trawler. (Photo: Fishing News.)
Spain (118 000 tons compared with 87 000 tons in 1965 by South Africa, and a total by all countries in 1948 of 39 000 tons). This expansion by industrialized countries has been both directly through increasing numbers of larger and long-rangefreezing and factory ships, especially from Eastern European countries, and also indirectly through investment in locally based fleets in the coast'alcountries. I n addition these countries are developing their own off-shore fisheries. Similar developments have taken place in the other oceans, particularly in the northern Pacific, from where Japanese and more recently Soviet fisheries have been expanding farther and farther afield. European and Japanese vessels are now exploiting the same stocks of fish, such as the hake off the south-west coast of Africa. Even relatively poor countries are rapidly developing long-distance fisheries ; Korea, for instance, has a substantial fleet fishing for tuna in the central Pacific and in the Atlantic.
II
I
I
I
I
I
I
I
I
I
I
I
I
I
I
FIG.7. The spread of overfishing ” in the North Atlantic. The years are the approximate dates by which fishing on the stocks indkated scnchd u lcvol heyond. which increases in fidiirig givc n o s u s h i i i d incruust: in total ca.tch. G , c:otl; H , ha,ddock; F , plaice; I?, redfish; I I K , h d r c ; Hg, herr,ing. ‘I
MANAGEMENT O F FISIIERY RESOURCES
15
There remain large stocks of fish which are still substantially unexploited, not only in under-developed areas, such as the oil-sardines (Xardinella spp.) and Indianmackerel (Rastrelliger spp.) in the Arabian Sea, but even in centres of intense fishing, such as the blue whiting (Hicromesistius poutassou (Risso)) off the west coast of the British Isles. However, despite the continuing improvement in fishing methods, the fishing gears in use now are fundamentally the same as those in use fifty years ago-the seines, trawls and hooks and lines. Similarly the types of fish being caught are the same, being those in which the diffused production of the sea has been concentrated either in large shoals, such as anchovies or sardines; on the bottom, such as the cods and flounders; or in large animals, such as tuna and whales, for which a single vessel can catch the animals from a very wide area (for instance one vessel long-lining for tuna can shoot 50 miles of line each day). Thus, despite the vast expanse of the open oceans in relation to the areas a t present exploited, the number of unexploited but practicably exploitable stocks of fish is not large, and unless there is a technical breakthrough which would make the harvesting of new types of resources economically feasible, e.g. the direct harvesting of krill (Euphausia superba Dana) in the Antarctic instead of indirectly via whales (Burukovskii and Iarogov, 1965 ; Stasenko, 1965 ; Osochenko, 1965), or of small oceanic fish, the present rate of expansion of the world fish production cannot be maintained indefinitely, possibly for no more than ten or fifteen years. Thus the proportion of the total world catch which comes from heavily exploited stocks needing proper management will rapidly increase, and it will become increasingly difficult to avoid the problems of proper management of an overfished stock by turning to other, less heavily exploited stocks. The need for proper management policies is therefore becoming rapidly more urgent. I n fact, the frequent failure to achieve proper management in the heavily exploited stocks is having immediate effects in several ways on the catches of lightly fished stocks. Most obviously, much more fishing effort in terms of ships, men and other resources is involved in the overexploited fisheries than would be needed under proper management, and these resources could well be directed to other stocks. Thus, for example, it has been estimated that the total effort spent on some of the major stocks of cod and haddock in the north-east Atlantic has increased so far that substantially the same (or possibly slightly greater) catch could be taken with half to two-thirds of the present level of fishing. If the resources, whether of ships, men or capital, represented by the excess half to one-third of the present effort, could be diverted to other less heavily fished stocks, e.g. in the central and south Atlantic,
16
J . A . CIJLLAND AND
J. E. CARROZ
and assuming that the catch rates of the individual vessels might be rather lower, a t least in terms of value, than when fishing for cod in the north-east Atlantic, their total catch would still be probably around half a million tons. Since the north-east Atlantic catch would remain the same, this half million tons would be a net addition to the total world catch taken a t no extra cost. The wrong type of management can also inhibit the development of fishing on unexploited stocks by discouraging or prohibiting the use of the most effective type of gear. Thus on the west coast of North America restrictions on the use of trawls, introduced to protect the catches of the highly priced halibut and the interests of sports fishermen, have hindered the exploitation of the very large stocks of hake and other species. Also the general failure to achieve good management is very likely to discourage governments or commercial interests from investing large sums in developing fisheries whose long-term future is uncertain. For these and other reasons proper management implies far more than merely ensuring, through appropriate regulations on the amount of fishing or the size offish caught, that the maximum sustained yield is taken from those stocks which would otherwise be overfished, important though this is.
B. Theoretical studies The effect of fishing on a stock of fish has been described by means of a range of models of varying mathematical complexity (see, for instance, Ricker, 1958; Beverton and Holt, 1957; Schaefer, 1954, 1967a; Schaefer and Beverton, 1963; Gulland, 1965, 1967); but the implications for rational inanagement are much the same. I n the absence of fishing a stock of fish will be large, including a relatively high proportion of big. old individuals, and the increase in the total biomass due to growth of the individuals arid recruitment of young fish will be balanced over a period by the losses due to naturaldeaths. When fishing begins the large stock gives large catches to each vessel, even though the total catch is small. Any fishing will tend to reduce the stock abundance,but at the reduced stock levels the losses due to natural deaths will be less than the gains due to growth and recruitment. If the catch taken is equal to this surplus, the stock will not change : any catch greater than this sustainable yield will decrease the stock, while a smaller catch will allow the stock to increase. This sustainable yield is small for very large stocks, because natural deaths are only just less than the growth and recruitment; equally it is small for very small stocks, where the absolute value of the increase due to growth and recruitment will be small. Thus the greatest sustainable yield will be taken a t some inter-
MANAGEMENT O F FISHERY RESOURCES
17
mediate stock level. This level may be achieved by some moderate amount of fishing on all sizes of fish, or pssibbly quite heavy fishing selectively applied to the larger fish. An example of this technique applied to a major oceanic fishery, the fishery for yellowfin tuna in the eastern tropical Pacific, is given in Fig. 8. The effect of fishing is best shown by relating the stock level (in this case measured by the catch per day fishing by a standard vessel) to the amount of fishing (here measured by the estimated number of days fishing). Each point in the diagram corresponds to the data for one year in the period 1934-65; the Figure shows clearly the decline in T o t a l catch,millions o f p o u n d s
1
v ) 3 0
L
a -
a L
Z
c '-
V c
m L'
F i s h i n g e f f o r t i n thousands o f s t a n d a r d d a y s FIG.8. Relationships among fishing effort, apparcnt abundance, and catch for yellowfin tuna i n the eastcrn Pacific Ocean, 1034-66. The points connected by thc solid line are based on apparent abundance mcasurcd by baitboat data only, while the isolated points for 1959-66 are h s e t l on apparent abundancc measiired by data from baitboats and seincrs combinctl. (From I.-A.T.T.C., i966.)
stock with increasing fishing, and the straight line which best describes this decline. Also shown in the diagram are curves connectingthe points with the samc total catch. For the observed line the highest catch is a t the point corresponding to an equilibrium catch of some 90 000 short tons, taken with an amount of fishing, in standard units, of 32 000 days. A more analytical approach is to follow the history of a brood of fish from the time they reach a fishable size, as in the models of Ricker (1958) and Beverton and Holt (1957). At low rates of fishing the fish may survive for a long time, so the average age and size are high;
18
J. A. CULLAND AND J. E. CARROZ
however, the total numbers caught, and the total weight, are small. Equally a t very high rates of fishing, applied as soon as the fish are big enough t o be caught, although the numbers caught will be very large, they will not survive long enough to grow much, so that the total catch will be only moderate, consisting of very small fish. The greatest catch from a given brood is taken by allowing the fish to grow to a reasonable size, either by only fishing moderately hard or by using some selective gear (e.g. trawls with large meshes) which will only catch the larger fish, allowing the small ones t o escape and grow. I n addition, it is not improbable that the average number of young produced by the low stocks when fishing is heavy will be less than those produced from larger stocks, although this is not as obvious as it may seem. Most marine fish produce very large numbers of eggs (sometimes millions), so that even a very small adult stock could produce a large brood, and evidence from some stocks shows that the adult stock can be reduced substantially without any significant reduction in the number of young produced which recruit to the fishery in later years (Beverton, 1962). The number of young produced each year often fluctuates very widely quite independently of changesin the adult stock, and these fluctuations make it very difficult within any particular stock of fish t o determine whether a reduction in the number of adults results, on the average, in any significant reduction in the number of young. This uncertainty has often, in practice, led to the assumption that the number of recruits is independent of the adult stock, i.e. that there is no need for regulatory measures to maintain the adult stock. However, this assumption can lead to disaster for the fishery if in fact it is false. The obvious example of the disasters following a failure t o maintain an adequate breeding stock is that of the Antarctic whales. Since they are mammals, producing only one young every other year, there is no doubt that a reduction in the adult stock would result in fewer young animals recruiting t o the future stock. Under proper management these Antarctic stocks could maintain annual catches of around 6 000 blue whales and 20 000 fin whales : a t present the blue whales have had to be given complete protection, but even if hunted intensively only a few hundred could be caught (Chapmanet al., 1964, 1965). I n the 1965-66 season only 2 300 fin whales were caught, and even this small total will only allow the depleted fin whale stock to rebuild rather slowly. Thus failure of proper management has meant a loss in annual catch of 6 000 blue whales, and 18 000 fin whales, which would have yielded about a quarterof a million tons of oil, and equivalent quantities of whale meat and other by-products. Similar disasters to fish stocks are less well established, but a possible example is the California sardine (Xardinops
MANAGEMENT O F FISHERY RESOURCES
19
caerulea (Girard))fishery, which declined from over half a million tons annually around 1940 to only 3 000 tons in 1963, due to failure of recruitment. It is possible that this failure of recruitment was caused a t least in part by the reduction in the adult stock by the heavy fishing of the 1930s and 1940s (MacGregor, 1964 ; Murphy, 1966). I n other major fisheries uncertainty concerning the relation between adult stock and subsequent recruitment is of immediate practical relevance in considering the present need for management. Thus for the Arcto-Norwegian stock of cod a reduction in the amount of fishing to half the high level occurring in 1965 would, if recruitment were independent of adult stock, result in a slight increase in sustained catch (I.C.E.S., 1966). However, there are definite signs that the recruitment is reduced a t the low stock correspondingto the 1965 level of fishing (Garrod, 1966) ;if so, continued fishing a t the 1965 level could very greatly reduce the stock, and result in sustained catches very substantially below those that could be obtained a t lower levels of fishing. Again, in the Peruvian anchoveta fishery, it is fairly clear that increased fishing will not appreciably increase the yield per recruit and any small increase in yield would be accompanied by a substantial fall in catch per unit effort (Boerema et al., 1965), and therefore it is desirable to discourage any further increase in effort. It is, however, possible that increased fishing, by reducing the spawning stock, will reduce the future recruitment; this reduction in recruitment could well cause a loss in total catch of several million tons per year. I n this case it would be not only desirable, but virtually essential, to prevent any appreciable increase in fishing. It is also conceivable, and consistent with the data a t present available, that reduced adult stocks would, because of reduced competition for food between adults and young, result in increased recruits ; increased fishing might therefore substantially increase the total catch. Having stated the uncertainty, it is not easy to resolve it. Certain theoretical models relating stock and recruitment have been developed and curves relating recruitment to adult stock proposed which ranged from the asymptotic to the parabolic (Ricker, 1954; Beverton and Holt, 1957 ; Radovich, 1962). However, the observed data, in the form of pairs of values of adult stocks and subsequent recruitment, are usually few (accumulatinga t the rate of only one pair per year), and are often very variable, so that the form of the stock/recruitment curve often remains very uncertain (Gulland, 1967). Probably the problems can only be resolved by a better basic understanding of the processes determining the survival from egg to adult, particularly the early larval stages. This will probably require both work at sea-detailed surveys
20
J . A. GULLAND AND J. E. CARROZ
of younger stages-to estimate the basic population parameters both of the young fish themselves and also of other relevant populations, especially the food of the larvae (Ahlstrom, 1954, 1965 ; Baranenkova, 1965), and work in the laboratory-estimation of food requirements of the larvae, the effects of reduced food on growth and survival, etc. This adds up to a substantial volume of research, but it is probably the field in which marine biological research has most to offer in improving the scientific advice on fishery management. Using the techniques outlined previously of estimating the population abundance, its rate of change, and the growth, mortality and recruitment rates, the biologist can draw up, with a greater or less degree of precision, sets of curves relating the total catch from a stock of fish to the amount of fishing and to the sizes of fish caught. These curves form the essential basis of proper management. I n drawing up these curves the biologist has to ignore, in the first instance, many of the complexities of the real situation. Thus the simplest, and most frequently used form of the Beverton and Holt yield equation ignores possibIe changes in the growth pattern, or in the naturalmortality rate. However as the authorsshow, any likely changes in these will not alter the general shape of the yield curves, and hence will not affect the nature of the biologists’ advice concerning a fishery which is to any extent “overfished ”. When, perhaps as a result of this advice, the fishery approaches to what may be its optimum condition, then these complexities, and others such as the interaction between different species, etc., may well have to be taken into account in order to define the optimum more accurately. There are other effects, in particular the precise nature of the relation between adult stock and the subsequent number of recruits, which, as discussed above, may alter the whole shape of the yield curves. However, the direction of the change will be generally known-at larger stocks (i.e. with reduced fishing mortality or increased size of fish caught)the recruitment (andhence future stocks and future catches) will almost certainly be greater than predicted on the basis of constant recruitment. Thus the yield curves, and assessments based on them, assuming constant recruitment, will be conservative, in the sense that they will provide a lower limit to the benefits from conservation actions. These relations between yield and effort and between yield and size of fish caught are interdependent, so that the form of the curve relating the yield to the size of fish caught depends on the amount of fishing. It will, except a t very low rates of fishing, have a maximum, and the position of this maximum will depend on the amount of fishing. The greater the amount of fishing, the greater will be the size of fish a t
MANAGEMENT
O F FISHERY RESOURCES
21
which the maximum occurs, and also the greater the catch a t the maximum, i.e. a t high fishing rates most fish will be caught, so that it is worth waiting until the fish are well grown, while a t low fishing rates it is better to start catching them when quite small as otherwise they may not be caught at all. Equally, the relation between the amount of fishing and the catch depends on the sizes of fish caught. At low rates of fishing, the catch will increase nearly in proportion to the increase in fishing, whatever sizes are caught (see Fig. 9). If small fish are caught, the increase in catch will soon become proportionally less than the increase in fishing, and the curve of catch against effort will tend to
FIG.9. The relation between fishing mortality and the averagc long-term catch.
flatten out, reach a maximum a t some moderate level of fishing, and decrease, possibly sharply if recruitment is affected, a t higher levels of fishing. If small fish are protected, e.g. by using large mesh nets, the catch will tend t o continue increasing with increasing fishing to higher levels of efforts, so that the maximum yield will be greater and occur a t higher rates of fishing. If only quite large fish are caught, the catch may continue to increase (but very slowly) with increasing fishing, however intense, and the greatest possible yield from a brood of fish would be taken by waiting until the fish reach optimum size and then harvesting them all. I n open waters such immediate harvesting would require an impossibly large fishing effort, but is, of course, common practice in pond culture or animal husbandry in general. The two families of curves may be combined to give contour diagrams showing the yield for any combination of fishing effort and
22
J. A . GULLAND AND J. E. CARROZ
size a t first capture (Beverton and Holt, 1957 ; Dickie and McCracken, 1955 ; Mako, 1961 ; Misu, 1964). Such curves describe the biological situation, but this is not all that is required for management. I n particular, the value of the catch and the cost of catching it must also be considered. The value of the catch will depend on biological factors such as the size of fish (small fish being nearly always less valuable than medium or large fish), and on their condition-fish which have just spawned, for example, often being not very valuable-as well as on economic factors such as the variation of price with supply. The factors can be introduced into the equation t o give expressions for the catch in value, but to a first approximation it is normally sufficient to take the value as being proportional to the weight caught, though most conservation measures tend t o increase the average size of the fish caught, and hence their average price. Other things being equal (and the results of regulation may well be to make them not equal) the cost of fishing will be closely proportional to the amount of fishing, but little affected by the sizes of fish caught. Therefore, if the size of fish caught can be regulated (and it may not be practicable for some gears, e.g. purse seines),the size should be regulated to give the maximum yield for the current amount of fishing, being adjusted as necessary if the amount of fishing changes. It is not so certain that, for rational management, the amount of fishing on a particular stock should be adjusted to give the maximum catch from that stock, even if such a maximum exists a t a practicable level of fishing. The fact that the well-being of a fishery cannot be measured solely by the total weight of the catch, and that there is a need for an objective of management less narrow than the maximum catch has been pointed out by many authors, both biologists and economists (e.g. Graham, 1943; Beverton and Holt, 1957; Schaefer, 1957b; Bell, 1959; Gordon, 1954; Christy and Scott, 1965; Gulland, 1968b). I n the absence of regulation, the fishery will tend to stabilize a t a level where the value of the catch is about equal to the total costs of catching. If the fish are valuable, and easy to capture, and also if small fish cannot be protected, then it is likely that this equilibrium will be reached a t a level of fishing greater than that giving the maximum sustainable yield. A reduction of effort to the level of the maximum yield should result in an increasein the value of the catch, and reduction of costs, and must therefore be beneficial, but a further reduction is also likely to be desirable. Close to the maximum the curve of catch against effort is very flat, so that a small to moderate reduction in effort will result in a negligible reduction of catch. That is, perhaps 98% of the
23
MANAGEMENT O F FISHERY RESOURCES
maximum catch may be taken with only SOYo of the effort required to take the maximum, and the cost per ton of taking the last 2% would be around ten times that of taking the first 98%. Blmost certainly the resources in ships, men and money in taking the last 2% would be much better employed elsewhere-even when the demand is for fish a t almost any cost there are likely to be alternative and relatively unexploited stocks t o which the surplus effort could be diverted. So long as alternative underfished stocks exist the apparent contradiction between the biological objective of greatest physical yield, and the economic objective of greatest economic yield (cf. Christy and Scott, 1965, p. 219) is valid only if considerationis restricted to the individual heavily fished stock. The greatest physical yield from the oceans as a whole will be possible only if the presently overfished stocks are harvested as efficiently as possible. The objective, therefore, of rational management should be to maintain the fishing effort a t the level giving the greatest net returns (value of catch less cost of capture),i.e. at the level where the marginal cost of adding one unit of effort (one extra vessel) is just equal t o the marginal value of the increase in hhe sustained catch resulting from the extra effort, rather than the marginal value being zero (if the effort is at the level giving the maximum sustained yield), or even negative (if the effort is past the maximum). This is shown diagrammatically in Fig. 10, in which the curve in Fig. 9 relating catch (in terms of weight) to the amount of fishing (basically in terms of the proportion of the stock removed per year) is replaced by a curve relating value of the catch to the cost of catching it. To a first approximation the value of the catch is proportional t o the weight caught, and the cost is proportional t o the amount of fishing. Then the equilibrium position is the point A where the line of equal costs and value cuts the curve. I n this example it is beyond the level of fishing which gives the maximum catch, A,, and a reduction of fishingto produce the maximum sustained yield will also produce a surplus of value over costs equal t o A,&. However, a further reduction of fishing to bring the catch to the point A , will produce an even bigger surplus A$,. This simple statement of the immediate economic aspects of management becomes more complex when considering several stocks of fish, or fishing carried out by several countries. Since each country will have different costs, and set different values to the fish, the optimum position for each country will be different. However, if two countries have been fishing the same stock for some time, without great changes, both will presumably have about the same equilibrium position, so that their optimum positions will also be similar. I n any case, if the total effort has increased beyond the A.M.B.-6
2
24
J. A. CULLAND AND J. E. CARROZ
costs FIG.10. The relation between costs of fishing and value of the catch. Point A , where the line of equal costs and values cuts the curve, is the equilibrium position without regulation. The greatest net return, A,-B,, is obtained by limiting fishing to about one-third of the equilibrium level.
level giving the maximum catch, it will be in the interest of all to reduce the effort, even if the magnitude of the reduction in the effort required to reach the various optimum positions may be different. Difference in national interests, and indeed differences between different groups of fishermen in the same country, are likely to be more serious when several stocks of fish of different species are concerned. No species of fish exists in isolation, but may compete with one species for food, be eaten by a second, and feed on a third, and all these stocks may be exploited by different fishermen whose catches will therefore interact. Also fishermen, while catching one species, may incidentally catch another species which is of primary interest to some other fishermen ; for example, in the North Sea, vessels trawling for herring often catch numbers of small haddock (Sahrhage,1959). In such situations it is normally impossible to take the maximum sustainable yield of all the species being exploited : for instance,the maximum yield of haddock would only be taken if no small haddock were killed by herring trawls, which could only be achieved by prohibiting trawling for herring, and this would reduce the catch of herring (I.C.E.S., 1960). Thus, a unique objective of management cannot easily be defined, though the biologist can, a t least in principle, calculate what the effects of possible regulatory action would be, and hence those regulations can be introduced
MANAGEMENT
O F FISHERY RESOURCES
25
which would improve the fisheries of the area as a whole. Thus the damage done by herring trawlers in reducing the haddock catches is less than the extra value of herring taken by the trawlers; therefore restriction of herring trawling to protect the haddock fishery would not be justified when considering the North Sea as a whole. This example also illustrates an important practical difficulty in complex fisheries. I n a simple fishery the restrictions and benefits of regulation can be equitably shared-if the effort should be reduced by 20%, then each group of fishermen can reduce their effort by SOY0, and their share of the catch will be unaltered. I n the North Sea, the losses are being sustained by the haddock fishermen (mainly Scotsmen) and the herring trawlers (from other countries) are unrestricted ; if the biological conclusionshad been different, and herring trawling should be restricted in order t o increase the total North Sea catch, then the losses would all have been t o the herring fishermen, and the gains to the haddock fishermen. These considerations do not, of course, make the need for proper management any less, but do increase the need for the proper quantitative understanding of quite complex biological situations, and for the balancing of the interests of each group of fishermen. They show that while the ultimate objective of fishery management in a region might well be to ensure the greatest total net yield from all the stocks taken together, this objective must be modified to ensure that the restrictions and gains are equitably shared. It may, however, still be attained if there is some system whereby those with the biggest gains pay compensation in some form to those with small gains, or losses.
111. METHODSOF REGULATION A. Types of regulation Any regulation can affect the stocks of fish and future catches only in one or both of two ways : by changing either the total fishing effort (i.e. the fishing mortality, the proportion of the stock caught each year), or the sizes of fish caught. However, a variety of different methods of regulation can be used to achieve one or other of these results ; they include : (a) limitation on the sizes of fish that can be landed ; (b) closed areas ; (c) closed seasons ; (d) limitation on the type of gear ; (e) limitation on total catch ; and (f) limitation on total effort. The effectiveness of these methods must be judged against the objectives of management, which will generally be to achieve the greatest surplus of total value of catch over the total cost of catching it. Thus, regulations to change the sizes of fish caught should not increase the cost of fishing ; regulations aimed at reducing the fishing mortality by some restriction on the amount of fishing, which are intended to
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J. A. GULLAND AND J . E. CARROZ
result in the long run in about the same, or possibly even greater, catches with less fishing, should ensure that the cost of fishing can be reduced roughly in proportion to the reduction in fishing mortality. The need for enforcement must also be considered and a good regulation should be both easy and inexpensive to enforce. An important step towards proper fulfilment of a regulation i s the belief by the fishermen that the regulation is necessary t o produce better catches in the future, and that foreign fishermen are also obeying the regulation (to many fishermen, a foreigner is anyone outside his immediate circle). To reduce this suspicion of “foreigners ”it is important that enforcement is not only effective but also seen to be effective. Lately several international commissions have taken steps towards joint enforcement by inspectors of different nationalities on each other’s vessels. (a) S i z e limits are effective methods of controlling the size of fish removed from the stock for those fisheries where undersized fish which are caught accidentally can be returned to the water alive, or where the fisherman can judge the size of fish before capture. Thus size limits are widely used in lobster (Homarusspp.)androcklobster (Panulirus,Jasus, etc.) fisheries, where the animals are caught in traps, and in whaling, where the gunner can judge the size of the whale quite closely before deciding t o fire the harpoon. I n most fisheries the chances of undersized fish surviving after being returned to the water are small. Even if the fish are alive when brought on deck, the fisherman’sfirst interest is in looking after the fish he is going to market (e.g. gutting them and putting them on ice), and preparing the gear t o catch more fish, and only afterwards may he return the undersized fish to the sea, by which time they will be dead. Even for lobsters a significant proportion of the undersized animalsmay die, either from the direct effort of capture and removal from the sea or from increased exposure to predators (Bowen and Chittleborough, 1966). Where few undersized animals survive, size limits by themselves will only reduce the present landings without helping to improve future catches or landings. However, size limits can be of indirect value by discouraging the fishermen from fishing in areas or with gears that would catch quantities of undersized and hence commercially valueless fish. They can help the enforcement of other regulatory methods, such as mesh regulation or closure of nursery areas, by reducing the economic attractions of infringement. (b) Closed areas and (c) closed seasons can be considered together as they can often be combined, i.e. closure of a certain area for a limited period, have similar effects and, in fact, for some migratory fish may be virtually equivalent. As limitations on the amount of fishing they are
MANAGEMENT OF FISHERY RESOURCES
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not likely to be ideal ; the fishing mortality may be reduced, but it is most unlikely that the costs can be reduced in proportion. Initially a closure of, say, 10% of the normal fishing season will reduce the fishing mortality and the running costs (but not the capital costs) by about l o % , but the long-term effects are likely to be the same as for uiiallocated catch quotas, discussed in more detail below, i.e. an increasingly wasteful entry of new vessels, etc., as the catfell per unit effort rises, necessitating a progressive shortening of the season to maintain the effort (mortality) a t the desired level. Closed areas or closed seasons can also be used to control the sizes of fish caught if there are areas where or times when small fish are particularly common ; for instance, the smaller fish of several species tend t o remain in inshore or shallower areas, and closure of these nursery areas would give effcctive protection of these smaller fish. I n addition, there nzay be times or places where the fish are in poor condition (e.g. after spawning), and when closure would allow the fish to recover and thus give a larger and more valuable catch. Such closures (other than a closure of all areas to fishing for a season) are particularly valuable when there are alternative grounds which can be fished profitably while the nursery areas are closed. Otherwise such closures would involve temporary lay-up of vessels, or diversion to an unprofitable fishery, and hence add to the cost of the fishery. (d) Regulation of the type of gear may be divided Into those banning or restricting the use of more efficient, or "damaging ", gears, i.e. aimed a t reducing the fishing mortality, and those, such as mesh regulations, aimed a t controlling the sizes of fish caught. The former types have little justification as a permanent feature of fishery management ; they only succeed in reducing the fishing mortality to the extent that they increase the costs of catching a given proportion of the stock. They may be necessary when increased fishing effort will severely reduce the total catch, e.g. by reducing the number of recruits, but when used they are an implicit admission of failure to achieve any ketter management. Regulation of the gear to control the sizes of fish caught, especially mesh regulation of trawls, are useful and have been introduced widely in the North Atlantic, and also in other areas, such as the East China Sea. Generally, they do not affect the cost of fishing, and indeed a trawl with larger meshes may be cheaper and fish more effectively on the larger fish. The selectivity of many gears, such as purse seines, cannot be altered in practice-they catch all the fish in a shoal-while that of others, e.g. long-lines, can only be altered rather imprecisely-larger hooks tend to catch larger fish, but the relation is far from exact. Even
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for trawls, selection takes place over a range of sizes. If it is desired to take fish of a certain size and bigger, the mesh size can be chosen t o retain half of the fish of the critical size, and release half of them, but some fish considerably smaller will be retained, and others considerably larger than the critical size will escape. If the fisherman sees some of these larger fish escape while he is hauling his net, he will become less willing to use larger meshes, especially as a fish in the water looks larger than one on deck. Because of the range of sizes over which selection takes place, and also because the selection apparently varies with the condition of the fish, the exact material and treatment of the twine in the net (especially the cod-end of the trawl), the magnitude of the catch, duration of haul, etc., the measurement of selection raises many practical problems (Gulland, 1964b). A considerable volume of literature has grown up concerned with the subject (see especially the report of the Joint I.C.N.A.F./I.C .E.S./F.A. 0. Special Scientific meeting (I.C.N.A.F., 1963) which contains papers not solely concerned with selection in trawls, and the reports of the various I.C.E.S. working groups (I.C.E.S., 1964, 1965)). For selectivity experiments outside the North Atlantic, see Aoyama (1961), Cassie (1955) and Longhurst (1959, 1960). A more serious limitation to mesh size and similar regulationsis that many of the fisheries to which they are applied exploit several species, which may be caught in the same haul. Especially when different groups of fishermen prefer different species, i t is impracticable to introduce a mesh size sufficiently large to provide effective regulation for the stocks of the larger species without causing unacceptable reductions in the catches of the smaller species. For example, in the North Sea the biggest catches of bottom-living species are of cod, haddock and plaice, all of which, and the trawl catch as a whole, would be increased by the use of meshes of 100 mm and over-probably for cod and plaice up to a t least 150 mm. However, i t has proved impossible to introduce meshes larger than 80 mm because they would cause losses of the smaller species (especially sole (Xolea solea L.) and whiting (MerZangusrnerlangus (L.)),and these are of major importance to some groups of fishermen. I n any case, even the mesh size (ca 110 mm) which would give the greatest total yield of all species would give considerably less than the sum of the yields from individual species, if the optimum mesh was used for each: ca 80 mni for soles and ca 150 mm for cod, etc. (I.C.E.S., 1957). The most fundamental disadvantage of mesh regulation as the only method of management is that its very success tends to cause changes which lose much of the benefits. The improved catches attract new
MANAGEMENT OF FISHERY RESOURCES
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entrants to the fishery, thus reducing the stock again until the returns to the individual fishermen are back to their previous level.
B. Limitation of the amount of Jishing Proper management must therefore include some control over the amount of fishing (the fishing mortality), through direct limitation of total catch or total effort, supported where necessary and practicable by measures such as mesh regulation to control the sizes of fish caught. Some of the practical problems depend on whether the amount of fishing is measured as input (fishing effort, e.g. number of hours fishing by a standard vessel, etc.) or as output (catch),but the more important question as far as many of the economic results are concernedis whether the total amount of fishing is set as a simple overall quota, and when this is reached all fishing stops, or whether individual quotas are set for each group of fishermen. If only an overall quota is set, then everyone will scramble to obtain the maximum share for themselves. This scramble, clearly predictable on theoretical grounds, has occurred in all the major stocks regulated by a simple quota ; for example, the Antarctic whaling (until the nations concerned agreed how to share the quota), or the Pacific halibut (Hippoglossus stenolepis Schmidt) (quotas have generally been set in terms of catch, but the same results may be expected if there is a simple effort quota, e.g. fishing continues until the effort totals 1000 days fishing). As a result of the increasing resources invested, and the correspondingreduction of the length of the season, the cost of exerting a unit of fishing effort rose roughly in proportion t o the reduction in total effort, leaving the total cost of capture about the same. Regulation by means of a simple unallocated quota cannot, in the long run, achieve any substantial reduction of cost, and the benefit of regulation and the reduction of effort will be limited to any increase in catch, though this may be substantial for some stocks (e.g. whales ; Gulland, 1966a). If the total quota is allocated to groups of fishermen within which competition is reduced or eliminated, then the dissipation of the potential benefits of regulation by excessive costs should not occur. Each group of fishermen can organize its activities so as to take its share of the catch a t the least cost, or perhaps take advantage of the benefits of regulation in other ways, e.g. one country might wish for social reasons t o ensure a living for the maximum number of fishermen. As regulation becomes effective and the stocks build up, the difference between the value of the catch and the cost of catching it will increase, possibly very greatly, making the right to a share of the catch increasingly valuable.
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For instance, it is likely that the cost of harvesting the salmon of the Pacific coast of North America could be reduced by about threequarters by having a management policy which allowed the most effective gears to be used. If such a policy could be introduced then the right to catch, say, $1 000 000 worth of salmon would be worth $750 000, the actual costs of capture, including a reasonable return on capital, accounting for only $250 000. Clearly in such a situation tlie problem of allocating the shares of the quota will become acute. In national fisheries these problems are soluble, a t least in principle. There is a central body which can enforce any decision as to how the quota is allocated, and ensure that fishing is not carried out by those with no quota. An attractive method that has been proposed is that the excess allocation should be reduced by charging a very substantial licence fee, equal to nearly the difference between value of catch and cost of capture (e.g. $700 000 for a licence t o take $1 000 000 worth o f salmon). The money obtained from these licences can then be spent in suitable ways: to offset all the cost of management and associated research, to provide research into alternative stocks, for general welfare of tlie fishermen, as well as a contribution to central government funds. The significanceof this scheme is that there is an explicit realization that in a well-managed fishery there may be a very considerable surplus of the value of the catch above the cost of catching it, and a definite decision is made as to who shall get this surplus. To some extent a t least the primary problem of fishery managemen-that fish stocks are a commoii property resource-has been overcome. Though the stocks do not become the property of tlie government or similar body, the government does have a large degree of authorityover the management. It also would have a direct financial incentive in proper management because the surplus of value over costs, and hence the price the fishermen would be prepared t o pay for licences, depends critically on the management methods. Internationalfisheries present much more complex problems in the allocation of the share of the catch, and particularly to countries wishing to enter a fishery for the first time. Many countries are rapidly expanding their fisheries, and would be most, unwilling to accept allocations based directly on the catches in previous years. If the target figures for future years are known, then a t least in principle they form in the short term an equitable and reasonable basis for allocation. At the least when allocating a quota for, say, 1970, the likely national sharesin 1970 in the absence of any regulation or allocationare probably a better guide to allocation than the catches in 1966. For instance, if a country a t present taking 20% of the catch plans to double its fishing,
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and if the othcrs do not change, its share would go up t o about 33%) the share of the others going down accordingly, Quotas allocated in these proportions would then be equitable in the sense that with regulation each country would take the same share of catch as it would have done in the absence of regulation. As the stocks build up under good management the allocation will become more difficult, since fishing will become more attractive and more countries will desire t o increase their fishery. I n whatever way the limit is set, either as a single overall quota or allocated to groups of fishermen, it must be defined either in terms of catch or amount of fishing, e.g. number of days at sea. The objective, in biological terms, is t o achieve a certain fishing mortality, i.e. t o capture a certain proportion of the stock each year. Neither the catch nor the amount of fishing (at least in readily measurable physical terms) will bear an absolutely constant relation to the fishing mortality. The catch corresponding to a desired fishing mortality will depend on the stock abundance,while the amount of fishing effort required to exert a given fishing mortality will depend on the efficiency of the operation chosen as the unit of effort (e.g. a day at sea by a vessel of a certain size) and whether the distribution and behaviour of the fish make them more or less catchable. The catch is readily definable in standard terms (though the increasing numbers of vessels freezing and processing at sea will complicate the precise measurement of the catch in terms of round fresh (live) weight). The definition of fishing effort in standard terms is much more difficult, especially if a limit is set as a single quota requiring the efforts exerted by all the vessels engaged in the fishery t o be expressed in the same terms. The difficulties of effort measurement are less if there is allocation of quota, explicitly or implicitly ; e.g. if all countriesagree to reduce their amount of fishing (as measured in various national units) by a certain percentage, or if limitation is set by issuing licences. I n the latter case the problem of standard measurement of effort may only become serious when a licensed fisherman wishes to improve his efficiency by getting a bigger or newer vessel, or by changing his type of gear. The measurement of the amount of fishing in terms of catch also has its difficulties, chiefly through the need to have a measure of the abundance of the fish stock. Many fish stocks fluctuate widely in abundance due to varying strengths of year-classes, while the quota for a year or a season must be set reasonably in advance of the season. Some system of forecasting the stock is required, and this can usually be done with a varying degree of precision, though sometimes requiring special rescarch effort, e.g. the use of research vessels to survey the 2'
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abundance of fish as yet too small to be fished. Fortunately, a t least with the longer-lived species, moderate errors in setting the quotas in one year can be corrected by suitable adjustment in the subsequent year without appreciable loss, but this does require that the administrative machinery for setting and adjusting the quota is reasonably rapid. The complexities of regulation are further increased when more than one species of fish is considered. Apart from the fisheries on shoalingfish such as anchoveta, herring, etc., few of the other important fisheries of the world are based exclusively on one species. Within a large fishing region the proportion caught of different species varies from ground t o ground, and also often from season to season on the same ground. The needs for regulation of the various species also tend to vary, possibly very widely; the more valuable species may be seriously over-exploited, while others be hardly exploited a t all. Proper management must therefore ensure suitable regulation for the former species, without discouraging fishing on the others, and this is not easy. Thus the success of the regulation of the Pacific halibut might be judged by comparing the catches in recent years of ca 15 000 tons of halibut in the Atlantic (where there are no special regulations to protect the halibut, which because of its potentially long life, slow growth, and high value is especially vulnerable to too heavy fishing) with nearly 40 000 tons in the Pacific, where halibut fishing is strictly regulated. However, it might possibly equally validly be argued that the failure of the halibut regulation is measured by the comparison of the total catches of all species from the areas in which halibut occur in significant quantities. About 1; million tons of other bottom-living fish (cods, redfishes and flounders) are caught annually off the east coast of Canada (T.C.N.A.F. areas 2-4), but until recently only about 60 000 tons were taken off the west coast of Canada and Alaska from the grounds covered by the Halibut Commission. I n the last few years very large catches have been taken in the area by trawlers from Japan and the U.S.R.R. but these countries are not members of the Halibut Commission. A most serious failurein a rather different way, throughnot considering individual stocks but only the overall total, has occurred in Antarctic whaling, where the stocks of blue, fin and sei whales have been in succession the main object of the industry (Fig. 11). Attention did not switch from the preferred to the next most preferred species (blue t o fin, or fin to sei) until the former had been drastically depleted. Although now only the sei whale stocks (the smallest stock of the three) are abundant enough to support any appreciable catches, the actual catches in any one of the past seasons which have so decimated the
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FIG.11. A whale catcher with its catch. A photograph taken in 1952 during the rich years of post-war whaling. (Photo: F.A.O.)
stocks were probably less than the annual catches which could have been sustained indefinitely if all three stocks had been maintained and harvested a t the optimum level. Ideally, therefore, separate limits (catch or effort quotas) should be set for each species, but this raises the problem when two or more species are caught together in varying proportions of what happens when the limit for one species has been reached. Often it is then uneconomic or impracticable to carry on a fishery directed solely on the other species. The experience of the International Whaling Commission does, however, suggest a possible technique for managing multi-species fisheries; that is by setting an overall quota, with catches of each
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species contributingtowards this quota with different weighting factors. For whales these factors were set to give approximately equal economic value, i.e. one blue whale unit (BWU) is equal to one blue whale, two fin whales or six sei whales; but they could equally well be set (and adjusted as necessary) to take into account the need for protection for each species. Thus in, say, 1955 the blue whde stocks were seriously over-exploited, the fin whales probably a t about the optimum level, and the sei whales virtually untouched. Appropriate factors might then have been 1 BWU = 0.5 blue whales = 2 fin whales = 15 sei whales
so that, provided also that the total quota had been allocated to countries or expeditions, there would be strong discouragement t o kill blue whales, and equally a positive inducement t o go after sei whales. This section cannot include all possible methods of regulation, and more especially all the problems likely to arise where they are introduced. Certain general conclusions can be made. Regulations controlling the sizes of fish caught can only be used in limited types of fisheries (e.g. in trawl nets where the mesh size can be changed). I n these fisheries they can have definite, if limited beneficial effects, but the benefits tend to be dissipated unless there is also control of the amount of fishing. The essential step in f ~ dmanagement l is therefore to control the amount of fishing and this will, in an overfished stock, produce a considerable surplus of value of catch above costs. An important decision should be made as to how, and by whom, this surplus shall be taken, otherwise it is probable that the surplus will be dissipated in some form of excessive costs. Rational management usually involves restriction of free entry into the fishery, which may be relatively easy in a national fishery or when a nation has been allocated a national quota, i.e. where there is a central body, having strong authority and powers of enforcement, but is not so easy in international fisheries. For these, limitation of entry may involve such questions as the extent of exclusive fishery limits, and the powers of internationalcommissions, and these are discussed in the following section.
IV. THE MECHANICSOF MANAGEMENTAND INTERNATIONAL LAW Nations can approach the problem of making fisheries management a reality in two ways: first, the national approach, by taking appropriate measures in sea areas off their shores over which they exercise sovereignty (territorial sea) or over which they claim jurisdiction over fisheries (fishery zones), fishermen of other countries usually being completely excluded ; second, the international approach, by setting
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O F FISHERY RESOURCES
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up international commissions with responsibility for somc particular fishery or groups of fisheries on the high seas. These approaches are closely related to the general questions of the law of the sea and to the principles of conservation of natural resources. Since the seventeenth century, when the development of seabornc trade and the emergence of powerful maritime nations led to a shift from the notion of closed seas claimed by a few countries to the concept of open seas, the two basic principles of the law of the sea have been that a strip of offshorewaters should be under the exclusive sovereignty of the coastal state and that the high seas beyond should be free. These principles were originally intended to satisfy and reconcile reasons of national security and the freedom of trade and navigation. But they applied to all activities in both areas and accordingly defined the legal framework within which fishing activities were carried on. The exclusive fishing rights of coastal states off their own shores and the freedom of fishing on the high seas are still the basic principles on which international fisheries law rests ; efforts have, however, been made recently to define more clearly the extent to which these rights and this freedom may be exercised. A. Territorial sea and fishing zones The exact delimitation of the sea where a coastal state enjoys exclusive fishing rights is of great importance, as it has a direct bearing on the regulation of fisheries and in particular demarcates these waters from the high seas where conservation and management problems are clearly international in nature, though the movements and migrations of many species of fish make such man-made limits often unrealistic. Until recently the sea area where coastal states had exclusive jurisdiction over fisheries was, in all cases, co-extensive with the territorial sea, i.e. the belt of sea immediately offshore where coastal states exercise sovereignty to the same degree as over their own land territory. The area claimed by any state as territorial sea, however, varied greatly between individual states, claims of areas from 3 t o 12 nautical miles being most common, though in exceptional cases claims covered a much wider area. The breadth of the territorial sea was considered by the United Nations Conference on the Law of the Sea in 1958. Although the Conference adopted a convention on the territorial sea, including rules on the baseline for measuring its width, no agreement was reached on the width itself (United Nations, 1958). A second Conference was held in 1960 ; there again no agreement was reached (United Nations, 1960). One proposal, which failed to be
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adopted by only one vote of the two-thirds majority required, had a definite influence on subsequent national and international measures. The proposal envisaged : (1) Allowing states to claim as territorial sea an area extending up to 6 miles from the coast. ( 2 ) Allowing states to claim exclusive fishing rights in a fishing zone immediately beyond the territorial sea extending up to 12 miles from the coast. States whose vessels had hahitually fished in the outer 6 miles of the fishing zone (i.e. the entire fishing zone if states claimed a 6-mile territorial sea plus a 6-mile fishing zone) for a period of five years immediately preceding 1 January 1958 would have been entitled to continue such fishing for a period of ten years after 31 October 1960. (3) Allowing a coastal state, subject to certain safeguards, to claim preferential fishing rights in any area of the high seas adjacent to its exclusive fishing zone, when it was scientifically established that a special situation or condition made the exploitation of the living resources of the high seas in that area of fundamental importance to the economic development of the coastal state or for food supplies for its population. Since 1960, several states have enacted legislation providing for an exclusive fishing zone extending to 12 miles from the coast. In addition, bilateral agreements have bccn concluded on the basis of the 1960 proposal and a European Fisheries Convention was signed in 1964. While the Convention does not contain any statement on the breadth of the territorial sea, it does provide that the contracting parties have the exclusive right to fish and exclusive jurisdiction in matters of fisheries within the belt of 6 miles measured from the baseline of their territorial sea ;within the belt between the 6 and 12 mile limit, the right to fish shall be exercised only by the coastal state and by any other contracting parties, the fishing vessels of which have habitually fished in that belt between 1 January 1953 and 31 December 1962. Thc right granted t o the fishing vessels of the other contracting parties is not limited in time, but they may not direct their fishing effort towards stocks of fish or fishing grounds substantially different from those which they have habitually exploited. Furthermore,the coastal state may, under the Convention, regulate fisheries within the 6-12 mile belt, provided that there is no discrimination in form or in fact against duly authorized fishing vessels of other contracting parties. The Convention does not specify that contracting parties will claim an exclusive 1 2 mile fishing zone with respect to all states not parties to the Convention.
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As can be seen, there is today an obvious lack of uniformity in the delimitation of the offshore area where coastal states have exclusive fishing rights. Thus, national claims vary as to the breadth of the territorial sea. Furthermore, in many countries, there is a trend to dissociate fishery limits entirely from the territorial sca. When states establish a fishing zone extending further than the territorial sea, the zone concerned is not always exclusive and fishing rights may be granted, either for a transitional period or without specified time-limit, to fishing vessels of certain other states. Mention should also be made of the recent practice whereby certain coastal states in Asia, without claiming jurisdiction over fisheries, reserve the right t o regulate fishing in a zone contiguous to their territorial sea and exclusive fishing zone, should this be necessary for conservation purposes. Such additional zone usually extends up to 100 miles.
High seas At the beginning of this century it had already been recognized that the living resources of the sea were not inexhaustible and that, in view of the freedom of fishing enjoyed by all nations on the high seas, it would be necessary to ensure the rational exploitation of the resources through international collaboration. At the same time, it became clear that more research was needed into the biological and environmental aspects of fisheries in the interest of this objective. As a beginning, measures to achieve co-ordination of scientific research and to take positive steps in managing the resources were taken on a regional basis. The InternationalCouncil for the Exploration of the Sea was established in 1902 to encourage and co-ordinate investigation of the eastern North Atlantic Ocean, including the waters off Greenland and Iceland. I n 1911 a convention was concluded for the preservation and protection of fur seals and sea otters in the waters of the North Pacific Ocean. The question arose as to whether it was possible to make a global approach to the problem of conservation and management of the resources of the sea by seeking the widest possible agreement not only on the basic principles which should govern all regional conventions but also on the basic rules t o be observed in areas of potential conflict. The League of Nations considered including the exploitation and conservation of the products of the sea among the subjects to be submitted to an international codification conference. The major fishing countries, however, believed that the diversity of the biological, economic and political problems arising in different fishing areas would
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make it preferable t o draw up regulations in relation to the needs of particular fishing areas, by agreement between the nations directly concerned. The general problem of the rules applicable t o the high seas was selected by the United Nations in 1949 for consideration as a topic for codification by the InternationalLaw Commission. The draft articles prepared by the Commission in 1951 contained a provision proposing that it would be the duty of states to accept as binding upon their nationals any system of fisheries regulation in any area of the high seas where an international authority believed that such measures were essential for the protection of the resources against waste or extermination. This international authority was to be created within the framework of the United Nations and could have acted at the request of any interested state. The provision concerned was not, however, retained in the final version of the draft articles submitted to the 1958 United Nations Conference on the Law of the Sea. The 1958 Conference adopted several international instruments, including a Convention on Fishing and Conservation of the Living Resources of the High Seas. The Convention, which came into force in 1966, is the first attempt t o deal with the problem generally on a world scale. Its scope is of necessity limited and i t aims mainly at promoting the adoption of conservation measures and a t providing for machinery designed to facilitate the settlement of disputes. It also contains provisions stressing the special interests of coastal states in the maintenance of the productivity of the living resources in any area of the high seas adjacent to their territorial sea and their right to take part on an equal footing in any system of research and regulation for the conservation of the living resources in that area, even though their nationals do not carry on fishing there. The 1958 Conference fully realized that the Convention referred to above would have to be supplemented by special and regional agreements. It adopted a resolution recommending that the states concerned should co-operate in establishing the necessary conservation measures through international conservation bodies covering particular areas of the high seas or particular species of living marine resources. It also recommended that these bodies should be used, in so far as practicable, for the conduct of negotiations on conservation measures envisaged in the Convention, for the settlement of disputes and for the implementation of agreed conservation measures. I n the resolution, the Conference specifically referred t o the report of the International Technical Conference on the Conservation of the Living Resources of the Sea, which had been convened in 1955 to make appropriate scientific and
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technical recommendations in preparation for the 1958 Conference on the Law of the Sea (United Nations, 1956). The 1955 Technical Conference had come to the conclusionthat the system of international fishery regulation based on the geographical and biological distribution of marine populations seemed, in general, to be the most suitable way of handling these problems. This system was based upon conventions signed by the nations concerned.
B. Xpecialized Jishery bodies Most of the existing internationalfishery bodies were established by conventions conchded after the Second World War. Five of them were set up under the auspices of F.A.O. pursuant to the relevant provisions of its Constitution. Certain fishery bodies were established to cover a particular sea or specified lake or river systems (e.g. the Joint Commission for Black Sea Fisheries or the Great Lakes Fishery Commission). Others were set up to serve a region of the high seas which is precisely delineated by longitude and latitude (e.g. the International Commission for the Northwest Atlantic Fisheries and the North-East Atlantic Fisheries Commission). The area of competence of many fishery bodies, however, is defined only in general terms (e.g. the Eastern Pacific Ocean for the Inter-AmericanTropical Tuna Commission or the Indo-Pacific area for the Indo-Pacific Fisheries Council). The absence of well-defined geographical limits may sometimes be advantageousin that it allows of flexibility in taking account of surveys and investigations into the biology of the species concerned. It should, however, be noted that each time member countries are requested to provide data to co-ordinate or conduct research, or each time a commission needs t o formulate conservation measures, a specific area has to be defined. What seems important is that the area of competence should be large enough to encompass the entire range of the stocks constituting the resource with which the commission is concerned. It may be mentioned in this connexion that most conventions setting up international fishery bodies include in their area of competence the territorial sea of member countries. The great majority of international fishery bodies were set up to deal with sea fisheries. Actually, a glance a t a map delineating, by oceans and seas, their areas of competence, would show that practically all the marine waters of the planet are covered and even, in certain regions, several times over. This should not, however, lead to the conclusion that all the living resources of the sea are the object of scientific investigation and management measures. I n fact, the
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composition, species coverage, functions, powers and activities of internationalfishery bodies vary considerably. The effectiveness of these bodies depends to a very great extent on the participation and collaboration of all the states concerned. Such states would normally be limited to those whose nationals and vessels carry out fishing operations in the geographic area served in the region. The provisions of the basic instruments concerning eligibility for membership do not always make it possible for all these states to participate. I n several cases the fisheries bodies are, as it were, land-based, since only states whose territories are situated in the area of competenee may become members. These include the Regional Fisheries Advisory Commission for the South-West Atlantic and the Regional Fisheries Commission for Western Africa, both set up under the Constitution of F.A.O. A certain number o f conventions do not provide expressly or implicitly for the possibility of later accessions, but this should not necessarily be interpreted as excluding the acceptance of new members. Several conventions provide that membership of the fisheries body is open, under certain conditions, to states other than the coastal states in the area of competence or t o states other than original members. Thus, any states whose nationals participate in fisheries in the area of competence o f the Inter-American Tropical Tuna Commission may become members of the Commission with the unanimous consent of the contracting parties. Only a few commissions are open to any states which adhere to the basic instrument simply by addressing the required notification to the depositary government. They include the International Commission for the Northwest Atlantic Fisheries, the International Whaling Commission, and the North-East Atlantic Fisheries Commission. When the membership of international fishery bodies is open, acceptance of all rights and duties as a member of such bodies is entirely voluntary. Under existing rules of international law, neither the states whose nationals or vessels carry out fishing operations on the high seas in the area of competence of a fisheries body, nor the coastal states in cases where a stock or stocks of fish inhabit both the fishing areas under their jurisdiction and areas of the adjacent high seas, may be compelled t o become full members of the body or to comply with any conservation measure it may formulate. The 1958 United Nations Conferenceon the Law of the Sea could only adopt recommendations on the subject, urging states concerned to co-operate. Many international fishery commissions and councils were set up to deal with all fisheries resources within their area of competence.
MANAGEMENT OP FISHERY RESOURCES
41
Notable exceptions are the International Whaling Commission, the North Pacific Fur Seal Commission, the International Pacific Halibut Commission, the Inter-American Tropical Tuna Commission, and the InternationalPacific Salmon Fisheries Commission. There are in practice marked differences in the manner in which fishery bodies deal with any particular stock of fish. This depends to a great extent on the functions of the body concerned. A first category of fishery bodies comprises those which deal mainly with the encouragement,promotion, and co-ordination of researchand which, in the course of their activities, may offer advice and make recommendations on the need for conservation measures. Examples of this type of body are the InternationalCouncil for the Exploration of the Sea, the International Commission for the Scientific Exploration of the Mediterranean Sea, and the commissions and councils set up under the Constitution of F.A.O. A second category includes fishery bodies, the main function of which is to formulate conservation measures on the basis of scientific research, but this research is not normally carried out by their own staffs (e.g. the International North Pacific Fisheries Commission, the Joint Commission for Black Sea Fisheries, the North-East Atlantic Fisheries Commission ; the last of these receives its scientific advice from another international body, the International Council for the Exploration of the Sea, included in the first category). A third category comprises the fisheries commissions which formulate conservation measures on the basis of scientific investigations carried out by their own staff. They are the Inter-American Tropical Tuna Commission, the International Pacific Salmon Fisheries Commission, and the InternationalPacific Halibut Commission. Conventions do not always specify the type of conservation and management measures that may be formulated by the international fishery bodies they establish. Detailed listing of conservation measures shows that these are normally confined mainly t o prohibitions and limitations ; these include most of the measures listed a t the beginning of the previous section: open and closed seasons or areas, minimum sizes of mesh of fishing nets, size limits of fish and regulation of the use of certain types of fishing gear, appliances and equipment. I n a few cases, the conservation measures expressly include prescribing a maximum or overall catch limit (e.g. InternationalCommissjoii for the Northwest Atlantic Fisheries, International Whaling Commission, and InternationalPacific Halibut Commission). Few commissions expressly include limitation of effort, and the North-East Atlantic Fisheries Commission places limitation of effort (and catch)in a separate,inactive,
,42
J . A. GCLLAKD
AND J. E. CARROZ
category of regulations which can only be actively considered after a specific recommendation to this effect has been passed by the Commissioii. Very few conventions list specific measures of a positive nature. An exception is the convention setting up the North-EastAtlantic Fisheries Commission which provides that the Commission may elaborate measures for the improvement and the increase of marine resources, which may include artificial propagation and the transplantation of organisms and of young. Before reaching agreement on the type of conservation measure that needs to be formulated, international fishery bodies normally consider not only the biological and simple economic effects outlined in the previous section, but also the problems of feasibility and enforcement. It should be pointed out that in most cases member countries are not under a legal obligation to comply with the conservation and management measures formulated by fishery bodies. The power of the majority of existing commissionsis limited to making recommendations, either because the convention concerned expressly so provides, or because the conservation measures have to be approved by member countries before they can be applied. I n a few cases a procedure has been evolved to facilitate acceptance of the measures formulated by commissions. These measures may be called potentially binding recommendations or conditional decisions. Thus the North-East Atlantic Fisheries Commission may recommend a number of conservation measures and member countries undertake to give effect t o any such recommendation adopted by not less than a two-thirds majority of the delegations present and voting. However, any member country may object to the recommendation within a specified period, in which case it is under no obligation to give effect to its terms. A somewhat similar procedure exists with respect to the measures formulated by the InternationalWhaling Commission and by the Permanent Commission for the South Pacific. When conservation measures are binding on member countries, each country is required t o ensure their application on the high seas by its own nationals and vessels. There is, however, a trend towards a certain measure of international control. I n fact, several conventions establishing fishery bodies (e.g. the International Pacific Salmon Fisheries Commission, the International North Pacific Fisheries Commission, the International Pacific Halibut Commission, the Japanese-Soviet Fisheries Commission for the North-West Pacific, and the North Pacific Fur Seal Commission) grant to each member country
MANAGEMENT OF FISHERY RESOURCES
43
the right to control the general application of conservation measures on the high seas as among the contracting parties. They prescribe, with certain differences of detail, a procedure whereby duly authorized officials of any member country may search and seize vessels of other member countries which are acting in violation of the convention or of regulationsadopted under it. Suchvessels must be delivered as promptly as practicable to the authorized officials of the member country having jurisdiction over them. Only the authorities of that country may conduct prosecutions and impose penalties. Though these commissions with interactional control measures a t present in operation have limited membership (a maximum of four countries), efforts to ensure international control are not restricted to commissions with a small membership or a limited species coverage. The Convention for the Regulation of Whaling was amended to enable the International Whaling Commission to deal with methods of inspection, and an internationalobserver scheme has been devised but it has not yet proved possible to bring it into operation. Both the InternationalCommission for the Northwest Atlantic Fisheries and the North-East Atlantic Fisheries Commission have also concerned themselves recently with the international enforcement of regulations in their area of competence and they have the matter under active consideration. International control will become increasingly important, as i t is gradually being recognized that, when scientific evidence calls for measures t o be taken, the purposes of conservation and management can best be achieved by limiting the amount of fishing (fishing mortality) either by control of the fishing effort or by regulation of the amount of total catch. The full benefit from limitation on fishing will, as mentioned earlier, only be achieved with some system of allocation of the total quota, whether of catch or of effort (e.g. days fishing). Several conventions contain provisions on the manner in which the yield from the resources is to be portioned among member countries. The convention setting up the InternationalPacific Salmon Fisheries Commission lays down the principle that the two member countries (Canada and the U.S.A.) should share equally in the fishery and, consequently, one of the tasks of the Commission is to regulate the fishery with a view to allowing, as nearly as practicable, an equal portion of the fish that may be caught each year to be taken by the fishermen of each member country. The convention establishing the North Pacific Fur Seal Commission, which has four member countries, provides for a system of quotas to
44
J. A . GULLAND AND J. E. CARROZ
ensure the distribution of the resources which migrate between the territory of certain member countries and the high seas. As all member countries agree to restrict killing of fur seals to the home islands and to prohibit sealing on the high seas in the Pacific Ocean north of the 30th parallel of latitude north, a portion of the total yield is granted to those member countries which do not own any islands on which the seals breed and which otherwise would have no share in the fishery as a result of their agreement not t o engage in sealing on the high seas. Of the total number of seal skins taken commercially each season on land, both the U.S.A. and the U.S.S.R. deliver to Canada and Japan 1.5%) each of the gross take in number and value. The convention setting up the InternationalNorth Pacific Fisheries Commission also contains provisions on the subject, as it embodies rules laying down what is known as the princiFle of abstention. According t o this principle, states not fishing a specific stock in recent years are required t o abstain from fishing this resource when states participating in the fishcries have created, built up, or restored the resource through the expenditure of time, effort and money on research and management, and through restraints on their own fishermen. It should, however, be scientifically established that the continuingand increasingproductivity of the resource is the result of and dependent on such action by the participating states, and that the resource is so fully utilized that an increase in the amount of fishing would not result in any substantial increase in the sustainable yield. Most conventions do not, however, prescribe how- the yield from the resource should be allocated. Internationalfishery bodies have thus to face this problem a t the time of fixing the maximum catch to be taken. For example, every year since 1961, the Inter-American Tropical Tuna Commission has recommended the establishment of a total catch limit of yellowfin tuna in a specified area of the eastern Pacific and the closure of fishing operations a t such date as the quantity landed plus the expected landings of vessels a t sea reach an amount slightly less than the total catch permitted. Under this system, fishing countries can freely compete for a maximum share within the total limit set by the Commission. This required, of course, not only the agreement of member countries but also the co-operation of other countries fishing in the area. As certain countries would prefer to be allotted a national quota, efforts are being made to reach a solution. Antarctic whaling may be cited as an example of a shift from the principle of free competition within an overall catch limit to the adoption of national quotas. While for many years the expeditions from the Antarctic whaling countries took part in what were known as
MANAGEMENT O F FISHERY RESOURCES
45
whaling Olympics ”, in an effort t o maximize their share of the total quota set by the Commission, the countries started negotiations in 1958 with a view t o agreeing on national quotas. An instrument was signed in 1962 for a four-year period. The overall limits are fixed by the International Whaling Commission, but the arrangements on the distribution of the total catch are made by the countries concerned. The general problem of allocation of the yield from the resources of the sea was considered to some extent by the 1955 International Technical Conference on the Conservation of the Living Resources of the Sea and to a greater degree by the 1958 United Nations Conference on the Law of the Sea. Discussions a t the 1958 Conference centred on the principle of abstention and on the concept of a preferential share for coastal states. No specific provision pertaining to the apportionment of the yield from the resources was included in the Convention on Fishing and Conservation of the Living Resources of the High Seas. The Conferenceadopted, however, a Resolution on the special situation of countries or territories whose people are overwhelmingly dependent upon coastal fisheries for their livelihood or economic development. The membership, area and scope of responsibility and main measures in use of the various Commissions have been set out in P.A.O. Reports (P.A.O., 1966b). Most of these Commissions issue extensive reports which outline not only the progress made in introducing various regulations, but also the results of the scientific research on which the regulations are based. C
lo3 halocnemoides, 103 indicum, 103, 119 zeiostachyum$ lo3 natalense, 119 quinquefzorum, lo3 Avicennia, 75, 76, 103, 129, 136, 139, 142, 143, 144, 145, 158, 172, 178, 180, 218 alba, 89, 112, 114, 133, 148, 149, 226 intermedia, 112, 113, 133 lanata, 93, 112, 226 marina, 82, 89, 92, 93, 99, 101, 102, 105, 112, 113, 114, 115, 117, 118, 119, 120, 125, 130, 131, 133, 134, 135, 141, 142, 144, 145, 146, 148, 149, 155, 161, 162, 166, 207, 220, 221, 222, 223, 224 nitida, 139 oficinalis, 93, 94, 97, 112, 161, 226 Azolla, 79
0 Balanus amphitrite, 167 Barringtonia asiatica, 87, 96 racemosa, 82, 86, 87, 93, 94, 96, 224 Bathyspadella, 280 edentata, 333 Batissa, 219 triquetra, 173 Eembicium, 219, 231 Birgus latro, 167, 212 Bitia hydroidea, 156 Boiga dendrophila, 156 Boleophthalmus boddaerti, 159, 179, 185, 188, 190, 194, 195, 197, 198, 199 Bombacaceae, 231 Bostrychia, 117 Brachylaena discolor, 86 Branchiomma vesiculosum, 364 Brownlowia tersa, 97
388
TAXONOMIC INDEX
Bruguiera, 77, 136, 139, 149, 150, 156, 158, 183 conjugata, 233 cylindrica, 93, 97, 105, 107, 110, 114, 177, 236 ezaristata, 105 gymnorhiza, 82, 89, 92, 93, 96, 97,99, 105, 107, 117, 118, 131, 144, 146, 149, 175, 220, 223, 234, 237 partiflora, 93, 105, 106, 110, 126, 131, 146, 148, 237 sexangula, 93, 94, 97, 99, 125, 131, 175, 237 Butorides striatus, 154
C Caesalpinia bonduc, 96 Calamus aquatilis, 97 Calianassa, 214 Callorhinus ursinus, 47 Caloglossa, 117 Camptandriumelongatum, 229 Camptostemon, 85 philippinensis, 231 schulzii, 231 Canavallia , 87 Carcinoscopius rotundicauda, 180 Cardisoma carnifex, 168, 169, 200, 201, 212, 224 hirtipes, 169, 212 Cassid ula, 2 1 8 angulifera, 173, 180 auris-felis, 174, 180 mustellina, 174, 180 Casuarina equisetifolia, 79, 87, 134 Catenella, 117 Ceratopogonidae, 160 Cerebus rhynchops, 156, 180 Cercopithecus mitis, 157 Ceriops, 139, 146, 158 decandra, 107, 110, 126, 142, 148 tagal, 92, 101, 103, 104, 105, 107, 110, 119, 120, 126, 131, 138, 141, 150, 174, 175, 177, 183, 220, 224 Cerithidea, 167, 240 alata, 174, 177 anticipata, 17 7
Cerithidea, cingulata, 177 decollata, 92, 102, 166, 173, 177, 221, 225 djadjariensis, 177 obtusa, 174, 177, 225 quadrata, 177 weyersi, 177 Ceryle maxima, 154 rudis, 154 Chaetognatha,280, 356, 359, 364 Chaetophora, 159 Chanos chanos, 122, 238 Chenolea diffusa, 102, 103 Chiromantes, 175 Chthamalus withersii, 167 Cleistostoma, 175, 200 algoense, 206 dilatatum, 21 1 edwardsi, 206 macneilli, 206, 211, 231 wardi, 206, 211, 231 Clerodendron inerme, 97, 233 Clibanarius longitarsus, 167 Clistocoeloma, 200 merguiense, 176, 180 Clupea harengus, 3 COCOS nucifera, 87, 134 Coenobita, 167, 212 Corvus albus, 156 macrorhynchus, 156 Corypha utan, 94 Crassostraea cucullata, 167 Crematogaster, 183 Crinum, 94 Crocodilus niloticus, 156 porosus, 156 Ctenodontina, 280 Culex sitiens, 160 Culicoides immaculatus, 160 mackayensis, 160 magnesianus, 160 naarmoratus, 160 molestus, 160 ornatus, 160 subimmaculatus, 160 Cyanchum armosum, 97
389
TAXONOMIC INDEX
Cyclograpsus, 200 Cymodocea, 88 Cynometra rami$ora, 107
D Daemonorops leptopus, 107 Dendronereis, I65 Derris heterophylla, 94, 107 trifoliata, 96, 224 Diplanthera, 88 Dolichandrone spathacea, 94 Dotilla, 200, 201, 202 fenestrata, 101 Dotilloplax kempi, 229 Dotillopsis, 200 brevitarsis, 229 Drosophila, 184 Ducula bicolor, 155 spillirrhoa, 155
E Egretta alba, 153 eulophotes, 153 gurzetta, 153 gularis, 153 Eichhornia crassipes, 79 Ellobiidae, 218 Ellobium, 218 auris-judae, 173, 174 auris-midae, 173, 174 Elysia, 177 Enhalus, 88 Enigmonia rosea, 165, 218 Entada, 224 phaseoloides, 96, 224 schefleri, 97 Epixanthus dentatus, 181 Eubalaena australis, 8 Euclea natalensis, 86 Eugenia suborbicularis, 144 Eukrohnia,274, 277, 280, 308-309 bathyantarctica, 308, 309, 333, 334 fowleri, 308, 309 hamata, 343 Eukrohnidae, 280
Euphausia superba, 15 Euplax, 200 tridentata, 231 Eurycarcinus integrifrons, 181 natalensis, 181, 225 orientalis, 225 Excoecaria agallocha, 85, 86, 97, 107, 120
F Ficus microcarpa, 93, 94, 107 retusa, 94 Pelis viverrima, 157 Flabellodontina, 280 Pluscisagitta, 280 Pordonia leueobalia, 156
G Gudus morhua, 3 Galeocerdo cuvieri, 2 16 Gecarcinids, 200 Gecarcinides, 2 12 Geloina coaxans, 173 Geograpsus, 168, 212 Glaucomya, 180, 219 Grapsidae, 200
H Haemonchus contortus, 363 Halcyon ehloris, 154 senegaloides, 154 Haliaetus leucogaster, 154 vocifer, 154 Haliastur indus, 154 Halodule, 88 Halophila, 88 Haminea, 176, 180 Helice, 200 crmsa, 231 leachii, 175, 224, 231 Heloecius, 200, 202 cordifownis, 211, 231 Hemiplax, 200
390
TAXONOMIC INDEX
Heritiera, 87 littoralis, 85, 86, 93, 94, 96, 97, 107, 119, 126, 219, 222, 224 Herpestes, 157 Heterokrohnia, 280 Heteropanope eucratoides, 181 glabra, 181 Hibiscus, 144 tiliaceus, 91, 96, 97, 142, 224 Hippoglossus stenolepis, 29 Hippopus, 120 Homarus, 26 Hydrophiidae, 226 Hydrophis .fasciatus, 228, 229 torquatus, 228, 229
I Ichthyophagus ichthyaetus, 154 Ilyograpsus, 175, 200 paludicola, 176 Ilyoplax, 175, 180, 200, 202, 213 delsmani, 176, 214, 229 lingulata, 176 obliqua, 176 punctata, 176 pusilla, 211, 230 spininrera, 176 Intsia bijuga, 93, 94, 107, 224 Ipomoea pes-caprae, 87, 134
J Juncus, 172 kraussii, 102, 103, 171 maritimus, 103, 171
K Kandelia, 76 kccndel, 97, 22 0 Krohnitta, 274, 277, 280, 343 subtilis, 344 Krohnittidae, 280
L Lagerstroeinia speciosa, 94 Lasiohelea townsvillensis, 160 Laternula, 180, 219
Leiopecten, 200 sordidulum. 180 Leptoptilos javanicus, 154 Littorina carinifera, 165 melanostoma, 165 scabra, 165, 218 undulata, 165 Lumnitzera, 133 littorea, 93, 96, 97, 125, 144, 233 racemosa, 96, 99, 101, 118, 131, 138, 139, 141, 142, 148, 149, 171, 224 Lutra maeulicollis, 157 perspicicillata, 157
M Macaca irus, 157 Macrophthalmus, 177, 200, 213 depressus, 102, 174, 176, 207 erato, 128 grandidiera, 101 japonicus, 21 1 latreillei, 179, 181 pacificus, 176 Mangifera indica, 141 Marphysa mossambica, 165 Melampus, 151, 218, 230 Malanogrammus aeglefinus, 8 Merlangus merlangus, 28 Merluccius, 3 capensis, 12 merluccius, 8 Mesosagitta, 280 Metapenaeus monoceros, 21 7 Metaplax, 200, 206 crenulatus, 178, 179, 213, 229 elegans, 180 tredecim, 229 Metasesarma, 200 Metopograpsus, 200 frontalis, 175, 208 latifrons, 177, 208, 213 messor, 175 thukuhar,175, 208 Micromesistius poutassou, 15 Mictyris, 201, 202 longicarpus, 160 Mimusops caffra, 86
TAXONOMIC INDEX
Mugilidae, 239 Murex adustus, 167 Murrayella, 117 Muscicapa ru$gastra, 156 Myomenippe hardwickii, 181
N Nannosesarma minuta, 167, 180 Nasalis larvatus, 157 Nemotoda, 361, 363 Nectarinia chalcostetha, 156 Nerita birmanica, 167, 174 Numeniusphaeopus, 155 Nycticorax caledonicus, 153 nycticorax, 153 N y p a , 85, 107 fruticans, 85, 84, 126 fruticosa, 86
0 Ocypode, 200 Oecophylla, 151, 158, 184 smaragdina, 158, 182, 183 Onchidiidae, 218 Oncosperma jilamentosum, 94 tigillaria, 99 Ophicardelus, 2 18 sulcatus, 173 Osbornia octodonta, 120, 133 Ozcroa obovata, 26 ozius guttatus, 181
P Pachycephala cinerea, 156 Pandanus, 97, 107 livingstoniona, 96, 134 tectorius, 96 Pandion haliaetus, 154 Panulirus, 26 Paracleistostoma, 180, 200 cristatum, 21 1 depressum, 176 longimanum,176 microcheirum, 176 Paramignya littoralis, 107
391
Parasagitta, 280 Parasesarma, 175 Parus major, 156 Pelargopsis capensis, 154 Pemphis acidula, 120, 133 I'enaeus indicus, 216, 217 japonicus, 217 rnonodon, 2 17 semisulcatus, 217 Periophthalrnodon schlosseri, 179, 180, 181, 185, 188, 189, 192, 194, 195, 198, 199, 200 Periophthulrnus, 152, 159, 198 argentilineatus, 185 chrysospilus, 179, 185, 186, 187, 190, 191, 192, 194, 195, 197, 199, 200 harmsi, 185 kalolo, 181, 185, 186, 187, 193, 224 koelreuteri, 185, 196, 197 sobrinus, 186, 188, 193 vulgaris, 185 Peronia peroni, 218, 221 Phalacrocorax africans, 153 carbo, 153 melanogaster, 153 niger, 153 Phascolosoma lurco, 181 Pheidole, 183 Phragmites, 1 19 communis, 86 Phragmophora, 280 Picus viridanus, 155 vittatus, 155 Pleuronectes platessa, 2 Polymesoda, 219, 226, 230 Potamididae, 218 Presbytis cristatus, 157 Pseudogelasimus, 200 Pteroptyx, 164 Pteropus, 157 Pterosagitta, 277, 280, 305-308 draco, 275, 286, 287, 288, 306, 307, 308, 309, 343, 344, 365 Pterosagittidae, 280 P y cnonotus goiaver, 156 plumosus, 156
392
TAXONOMIC INDEX
Pyrazus ebeninus, 218 Pythia, 218 scarabaeus, 173, 174
R Rana cancrivora, 156, 177, 181, 182 limnocharis, 157 Rastrelliger, 3, 15 Rhipidura javanica, 156 Bhizophora, 76, 77, 105, 117, 121, 136, 142, 143, 144, 149, 157, 167, 208, 236 apiculata, 89, 93, 97, 99, 108, 110, 111, 120, 126, 140, 148, 150, 162, 177 mangle, 139, 232 mucronata, 82, 89, 92, 99, 101, 108, 109, 110, 111, 114, 118, 131, 134, 141, 142, 146, 148, 149, 150, 177, 220, 224, 234 stylosa, 106, 108, 110, 118, 119, 120, 131, 150, 177, 220, 232 Rhizophoraceae, 76, 85, 136, 145, 146, 153
S Sagitta, 272, 280, 293-300, 316, 329, 355, 358, 362 bipunctata, 275, 287, 288, 291, 293, 295, 297, 289, 300, 309, 313, 332, 335, 336, 338, 339, 344 crussa, 274, 275, 282, 322, 330, 344, 348, 365 decipiens, 297, 309, 344, 346 elegans, 293, 309, 335, 344, 345, 364 euxina, 279 friderici, 274, 279 ferox, 330 guzellae, 344, 345, 346 hexaptera, 278, 279, 281, 282, 344 hispida, 274, 275, 338, 343, 346, 365 inflata, 278, 279, 280, 281, 288, 290, 291, 293, 295, 297, 309, 310, 313, 317, 318, 319, 332, 335, 336, 339, 344, 346, 347, 348, 351, 354 lyra, 277, 297, 344, 346
Sagitta, minima, 278, 293, 300, 309, 344, 354 neglecta, 330 pulchra, 281, 282 scrippsae, 273 serratodentata, 274, 275, 291, 332, 333, 344 setosa, 278, 279, 309, 310, 318, 330, 331, 332, 336, 344, 347, 350, 354, 365 Sagittidae, 280 Sagittoidea, 280 Salicornia, 88, 160 Salinator, 2 19 burmana, 226 Surdinella, 3, 15 Sardinops caerulea, 19 Sarmatium, 200 crassum, 175 Scopimera globosa, 230 intermedia, 229 proxima, 229 Scopus umbrettus, 154 Scylla serrata, 230, 240 Scyphiphora hydrophyllacea, 93, 105 Sebastes, 3 Seriolu guinqueradiata, 2 Serratosagitta, 280 Sesarma, 151, 152, 200, 201, 207, 212, 221 bataviana, 2 13 brevicristatum, 23 1 catenata, 221, 225 chentongensis, 171 crassimana, 17 1 darwinensis, 232 dussumieri, 175 erythrodactyla, 21 1 eulimene, 92, 171, 207, 21 1, 225 eumolpe, 175 fascia&, 171 guttatum, 92, 175, 225 indiarum, 175 indica, 171 inerme, 171 johorensis, 229 jousseaumei, 225 kraussi, 228, 229 lepida, 229
393
TAXONOMIC INDEX
Sesarma, lividum, 231 longipes, 225, 228 mederi, 171, 213, 225 meinerti, 92, 158, 171, 172, 207, 213, 214, 224, 231 melissa, 175 minuta, 225 moeschi, 171 nodulifera, 213 oceanica, 2 25 onychophora, 175, 229 ortmanni, 92, 102, 171, 207, 211, 225 plicata, 171 palawanensis, 171 quadrata, 2 25 rectipectinata, 229 sediliensis, 171 semperi, 229, 231 singaporensis, 171 smithii, 92, 170, 171, 172, 224, 231 tetragona, 171 versicolor, 171 Sesuvium portulacastrum, 99, 102, 103, 172, 174 Sideroxylon mime, 86 Solea solea, 2, 28 Solidosagitta, 280 Sonneratia, 77, 82, 126, 129, 136, 139, 142, 143, 149, 178, 180, 218 alba, 85, 92, 115, 116, 117, 119, 120, 125, 131, 133, 141, 144, 145, 148, 149, 162, 219, 224, 226 apetala, 115, 125, 131, 133, 142, 148, 226 caseolaris, 85, 94, 97, 117, 131, 158, 161, 162, 163, 183, 233 grifithii, 89, 115, 116, 125, 131, 133, 135, 148, 149, 158, 234 Sophora tomentosa, 87 Spadella, 227, 280, 291, 296, 300-305, 312, 218, 339-343, 350 cephaloptera, 275, 276, 282, 283, 284, 286, 287, 297, 302, 303, 309, 311, 313,316, 319,320,322-329, 339, 341, 349, 351, 352, 353, 354, 358, 365 Spadollidac, 280 Spilonis cheela, 154 Sporobolus virginicus, 119
Sus scrofa, 157
Syncera, 151, 219 brevicula, 177, 180 Syringodium, 88
T Tachypleus gigas, 180 T a i u s tumifrons, 8 Telescopium mauritsi, 173, 177, 180, 218 telescopium, 173, 177, 180, 218, 226, 240 Terebralia palustris, 173, 176, 218, 221, 224, 230 sukata, 173, 176, 218, 225, 230 Terminalia catappa, 93, 94, 96 Thais tissoti, 167 Thalassia, 88 Thalassina anomala, 97, 107, 108, 121, 123, 148, 169, 171, 175, 200, 208, 214, 230 Thespesia populnea, 96, 134, 222, 224 Thespesiopsis mossambica, 96 Thoracostoma californicum, 363 Tilapia mossambica, 123, 239 Tmethypocoelis, 200 Tragus, 157 Timeresurus purpureomaculatus, 156 wagleri, 156 Tringa terek, 155 totanus, 155 Tylodiplax, 175, 200 tetratylophorus, 176 T y p h a , 119
U Uca, 200, 202, 206, 214, 221 angustifrons, 229 arcuata, 21 1 bellator, 174, 176, 203, 210, 211, 212, 231 chlorophthalmus, 176 coarcta, 179, 180, 211, 231 consobinus, 2 10 dussumieri, 172, 179, 180, 202, 203, 205, 231, 232
394
TAXONOMIC INDEX
Uca, gaimardi, 176, 181, 209, 210 in.versa, 101, 174, 203, 209, 210, 211, 225 Zactea, 92, 101, 102, 172, 174, 201, 202, 203, 205, 209, 210, 211, 224, 230, 231 longidigitum, 2 11, 2 12 manii, 176 minux, 202, 203 pugilator, 202, 203 pugnux, 202, 203 rhizophorae, 180, 229 rosea, 176, 180, 229 triangularis, 180 universa, 92 urvillei, 181, 202, 203, 205, 210, 225, 232 vocans, 203, 209, 210, 211, 224 Upogebia, 92, 123, 180, 200, 208, 214 africana, 208, 221 pugettensis, 208 Utica, 200 borneensis, 176
V Varanus niloticus, 156 salvator, 156
X Xylocarpus, 133, 149, 150, 183, 224 australasicum, 138 granatum, 89, 93, 94, 97, 105, 107, 125, 126, 133, 140, 142, 147, 148, 220, 234, 237 moluccensis, 93, 97, 105, 107, 138, 139, 148, 234
Z Zonosagitta, 280 Zostera, 88 Zosterops chloris, 156
Subject Index A
B
Abstention principle, 53 Adelaide (Australia),220 Aerial roots, see Pneumatophores Africa difference of shores from Australian, 222 mangrove fauna of, 231 mangroves in, 219, 221 Agulhas current, 222 Algae, 117, 122, 159, 218 blue-green, 123, 239 green, 123, 239 Alluvium, 122 “fossil”, 122 AZpheus labyrinths, 200 Amphibians, 156 Anchoring roots, 138, 139 Anchoveta, 19, 32, 50 Annelids, 360 Ants, 151, 183 colonies, 182 nests of, 158 tailor, 151, 153, 182, 183 weaver, 158, 182 within mangals, 183 “Arrow worms”, 272 Asia, 219, see also regional entries Associations, see Plant Associations Atlantic, see North Atlantic Australia difference of shores from African, 222 mangroves in, 219, 220 species typical of, 231 Western, 231 Avicennia difficulties of taxonomy of, 112 intermediates, 112 “nurse” effect of, 149 seaward fringe of, 112, 114 wide distribution of, 144 Avicennia parkland, 92, 102, 172, 174
Bacteria nitrifying, 122 sulphate reducing, 122, 123 sulphur, 122 Barents Sea, fishing in, 10, 48 Barnacles, 115, 167 Barringtonia association, 87, 88, 89, 96, 125, 133, 225 Bashee river, 220, 221 Beaches levelling of, 129 particle sizes of, 201 Bees, 157 Bengal, Bay of, SO, 96 Birds associated with mangals, 153-156 not specializcd, 181 Bivalves, 180, 218, 219 Blastogeriesis, 351 Borneo, 80, 83 eastern, 223, 230 Bostrychietum, 117 Bottom-living species, see Deniersal species Bruguiera cylindrica association, 107 Bruguiera forcsts, 105-108, 125, 126, 134, 218 animals of, 174 types of, 105 variants of, 107, 130 Hruguiera gymnorhiza association, 107 Bunbury (Australia),220 Burrows, l68,172,174,179,18O,l84,200 importance in feeding of thalassinideans, 208, 214 permanent, 201 uses of, 214
395
C Cable roots, 137, 138, 140 Calcareous material, 121, 123 Carnivores, 157 Caterpillars, 158 Celebes, 230
396
SUBJECT INDEX
Ceriops thicket zone, 103, 104, 118, 134, 218
animals of, 174 Chaetognaths accessory fertilization cells in, 297300, 301, 302, 304,305,
307, 335
affinities of, 355-357, 359-363 as fishing indicators, 344 as isolated phylum, 357 biology of, 271-366 bristles of, 275 caudal segment, 279, 290 characterswith systematic or adaptational value, 272 crescent cells, 296 cross-fertilization, 332 cycles of sexual maturity in, 344, 345-350
diploid number of, 309 early development phases of, 316, 317
embryology of, 356 feeding movements of, 276 female gonads of, 292-297, 300-309 fertilization of, 322-334 growth of, 346 hermaphroditenature of, 289, 330 hooks of, 274 influence of environmental factors on, 343-344, 365 integument of, 274 laboratory experiments on, 364-365 life span of, 345 longitudinal septum, 290 male gonads of, 290-291, 309 mating of, 322 morphology of, 271-289 muscles of, 361-362 new classification of, 280 oogenesis in, 311 origin of, 358 possibility of self-fertilization in, 322, 328
regeneration in, 351-355 regions of body, 272 reproduction of, 289-350, 365 spermatogenesis in, 309-31 1 spermatogonia, 290 spermatophores, 323, 324, 325, 326, 327, 329, 330, 333
Chaetognaths-continued spermatozoa, 294, 298,
306, 308, 310, 311, 324, 327, 328 migration of, 326, 328 survival of winter by, 350 suspension apparatus in, 297, 298, 299 systematics of, 280, 355, 358-359, 363-364 Channels,in mangal, 133
Charcoal production, from mangrove, 235, 236
Chelipeds, of Uca, 202 Chemotactic action, 328 Cheniers, 79, 80, 134, 136 Chlorinity, 2 1 1 optimum range for Sagitta crassa, 349
Chromosomes, 309, 310, 338 lampbrush, 301, 312 precocious migration of, 310 Ciliary loop, see Corona ciliata Clines, 152 Closed areas, for fishing, 26, 27 Closed seasons, for fishing, 26, 27 Coastal sediments, 82 accretion of, 83, 149, 150, 238 influence of mangroves on, 83 Coconut groves, 240 Cod, 3, 10, 28, 55 landings of arctic, 11 stocks of, 19 Coelom cavity, 290, 296, 300, 352 “Collarette”, 275, 348, 352 Conservation measures, 41, 43 for whales, 55 international control of, 42 43 problems of feasibility and enforcement, 42 Convention on Fishing and Conservation of the Living Resources of the High Seas, 38, 45 Convention for the Regulation of Whaling, 43 Coral reefs, 77, 79, 110 Cormorants, 153 Corona ciliata, 279, 281, 282, 283, 284, 285, 286, 300, 327, 360, 36h
annularcanal of, 283 cells of, 283, 288
397
SUBJECT INDEX
Corona ciliata-continued characteristic of chaetognaths, 282 function in regulating migration of spermatozoa, 285, 328 glandular functions of, 286 researches on, 283 seasonal variation in, 348 secretion of, 284, 285 section of, 287 sensory funct,ionof, 283, 286, 289 structure in pelagic chaetognaths, 334 variations of, 281 Crabs, 75, 128, 135, 151, 152, 165, 167, 174, 175, 176, 177, 180, 181, 192, 201, 237 as food, 201, 240 breathing specializations of, 212 burrows of, 168, 172, 174, 203, 214 “castle building” by, 168 claw forms of, 224 demands on substratum, 206 distribution along estuary, 211 distribution of ocypodid, 206 feeding of, 202-203, 206, 207, 208 fiddler, 172, 179, 205, 232 land, 168, 212 more numerous in warm weather, 209 non-burrowing,207, 208 of Indo-Malayanregion, 229 pumping of water by, 213 temperature relationships of, 209, 210 water intake by, 203 water oxygenation mechanism, 212213 Creeks, in mangal, 133, 176 Crocodiles, 156 Crows, 156 Crustaceans, 230 breathing specializations of, 212 burrowing by, 214 effects of humidity on, 210 effects of substratumon, 201 effects of temperatureon, 209 effect of water saltness on, 211 specialized, living in mangals, 200 Currents, effect on mangals, 136 Cymoclocea association, 88
D Dampierian Province, 232 Darters, 153 Demersal species, 9, 10, 28, 32 Descriptive ecology, 74 Desiccation, ability of animals to resist, 184 Dhows, 77 Diatoms, 207 Diploid number of chaetognaths, 309 “Distant water” fishing grounds, 9 Drainage channels, in Avicennia parkland, 174 Durban Bay, 79
E EcologicaI differences between species, 185 Egg-laying in Sugitta, 335, 337 in Spadella, 339-343 preferred times in various chaetognaths, 335 Eggs of chaetognaths, 319, 320, 321, 336, 338, 349 production by marine fish, 18 Embryonic reserve, 355 Epidermis, multistratified nature of, in chaetognaths, 275 Epifaunaof mangal, 165 Epithelium, 303, 306, 308 cells, 352 Erosion following removal of a mangal, 136 of mangal shores, 126, 128, 135 of rhizophora forest, 135 Estuaries, penetration of mangroves into, 82 European Fisheries Convention, 36 Euryhalinity,232 Externalgenital papilla, 295, 302, 303, 307, 333, 342 Eyes of chaetognaths, 273 characters in species determination, 273-274 cups, 273
398
SUBJECT INDEX
Eyes of chaetognat,hs-continued fimct,ions, 274 photo-receiving cells, 273 strrrct>rire of, 273
F Facics, of maugals, 91, 118 “Farmingthe sea”, 54 Female reprodnct,ive apparatus of chaet,ognaths, activit)y cycles of, 347 of Eukrohnia, 308--309 of f’terosagitta, 305- 308 of Sagitta, 293-300 of Spadella, 300-305 origiii of, 319 Ferns, 237 Fertilization, in chaetognaths, 335 in Eukrohniabathyantarctica,333,334 in p-lagic chaetognaths, 334 in Sngitta, 329-333 in Spadella cephaloptem, 322-329 Filariases, mosquito carriers of, 151 Fins, of chaetognaths, 178 amorphous substarice in, 277 anterior, 279 caudal, 277 form of, 278 lateral, 276, 277 position of, 278 posterior, 279 rays of, 278 regeneration of, 353 Fireflies, synchronousflashing of, 161164 frequency, 164 optimum density for, 163 questions concerning, 163 rhythms of, 162 temperature control of, 164 Fish depletion of resources of, 7-16 in mangrove areas, 122 percentage of t,ot,al animal protein intake, 2 pond culture of, 238-240 underfished stocks of, 23 unexploited, 15 world production of, 1
Fish meal, 2 Fish ponds cycle of production in, 238-239 green manuring of, 239 harvesting of crop, 239 making of, 238 of Java, 238 prawns in, 217, 240 protein production, 239 tidal canal system, 238 yields, 239, 240 Fisheries complex, 25 international,30 national, 30 Fishery bodies, specialized, 39, 40 for part#icularregions, 39 for research, 41 for sea fisheries, 39 list of international,62-71 to formulate conservation measures, 41 Fishery management aim of, 6 bodies concerned with, 62-71 effects of wrong, 16 international,53 lack of basic data for, 52 mechanics of, 34-45 national approach to, 34 need for, 15 need for scientific knowledge, 51 objectives, 22, 23, 25 prospects for future progress in, 45 requirements for full, 50, 52 stock and recruitment, 19 Fishery regulation assessing effect of, 51 effectiveness of various methods, 25 enforcement, 26 fixing maximum catch, 44 methods, 25-34 types of, 25 with several species, 32 .Fishing effect on stock of changes in, 7 group quotas for, 29, 31 interaction of catches, 24 limitation of amount of, 29-34, 43 measurement of catch, 31
399
SUBJECT INDEX
Fishing-continued overall quotas for, 29, 33, 34 relation between mortality and catch, 21 stock recovery on reduction of, 8 theoretical models of cffect of, 16, 19 value of catch vs. cost, 22, 24 yield curves, 20 Fishing gear, 15, 16 regulation of, 27 selective, 18 Wishing mortality, 29, 31, 43 Fishing rights of coastal states delimitation of, 35, 36 preferential, 36 Fishing zones, 36, 37 Wlavins, 285 Flying foxes, 157, 181 Frogs, 156, 181-182 salt tolerance of, 182 Fruit bats, 75 Fruits of mangrove species, 145, 147, 148 Fur seals, 37, 47, 49, 53
G Gastropods, 151, 217, 231 Gastrulation, 318 Gelatine, of chaetognathootheca, 308 Germ cell determinant, 300, 313, 316, 320, 321, 322 function of, 316 origin of, 316 Germinal line, segregation of, 313, 318, 351 Gonads of chaetognaths, 289-309, 313 maturity stages of, 314-315 Great Barrier Reef, 79, 120, 155 Gross physical yield from fishing, 52 Gullies, in mangal, 133
H Haddock, 8, 10, 28 Hake, 3, 8, 12, 16 Halibut, 3 Atlantic, 32 Pacific, management of, 9, 29, 32 restriction of catch of, 47
Halibut Commission, 32 Halophytic plants osmotic pressure of. 141 physiology of, 140 Hermit crabs, I67 Herons, 153 Herring, 3, 12, 32 High seas, 35, 37 Honey, of Aegiceras, 157 Hutan darat, 93 Hyalinc substance, round eggs of Pterosagitta, 305 Hydrogen sulphidc in soils, 121, 139 Hydrophiid snakes, 156
I Iceland, fishing off, 10 Indo-Malayanregion, 223, 226 Indo-PacificFisheries Council, 39 Indo-west Pacific region, 77,78,8Y, 108 divisions on basis of endemic fauna, 223 east central division, 223, 226-229 Eastern Borneo division, 223, 23023 1 Lesser Surida Isla~idsdivision, 223, 231-232 littoral fauna and flora of, 222 marine flora of, 223 New Guinea and Queerisland division, 223, 231 north-easterndivision, 223, 230 Pacific islands division, 223, 232-233 west central division, 223, 226-229 Western Australia division, 223 western division, 223, 225 Infaunaof mangal, 165 Inhaca Island, 79, 87, 102, 126, 131, 216, 221 mangrove distribut,ion at,, 132 southern element of faima at, 221 tropical element of fauna at, 221 Inhambane,219, 220 Inland waters, fishery niariagernentin, 5 Insects, 151, 153, 157-164, 182-184 biting, 158 Inter-American Tropical Tuna Commission, 39, 40, 41, 44
400
SUBJECT INDEX
International Commission for the Northwest Atlantic Fisheries, 40, 41, 43 International Commission for the Scientific Exploration of the Mediterranean Sea, 41 InternationalCouncil for the Exploration of the Sea, 37, 41 InternationalLaw, 34 of the sea, 35 International North Pacific Fisheries Commission, 41, 42, 44 International Pacific Halibut Commission, 41, 42, 45 InternationalPacific Salmon Fisheries Commission, 41, 42 InternationalTechnical Conference on the Conservation of the Living Resources of the Sea, 45 International Whaling Commission, 33, 40, 41, 43, 45, 46, 48 Intertidal range, 126 Inundationfrequencies, 89 Ionic balance, 211
J Japanese-Soviet Fisheries Cornniission for the North-West Pacific, 42 Java, 83 Joint Commission for Black Sea Fisheries, 41
K Kagoshima Bay, 220 Kariograms, 310 Kariosomes, 3 12 Kei River, 220 Kingfishers, 153, 154 Knee roots, 139 Krill, 15 Kuro Shio current, 222
L Labrador Banks, 12, 13 Landward fringe of mangal, 91-103, 125 animals of, 167-174
Landward fringe of mangal-continued following forested supralittoral,91 following on savannah, 99 transition to, 107 Law of the sea, 35 conferences on, 35, 36 League of Nations, 37 Lesser Sunda Islands, 231 Licence fees, 30, 31 control of fishing by, 54 Limit of fishing, defining, 31 Lipoids, 278 Lobster, 26 as food, 2 mud, 121, 169, 175, 208, 209 rock, 26 Lourenpo Marques, 79, 82, 126, 144, 220, 221 Lower lethal temperature of crabs, 210 Lunzlzitzeru littorea association, 93
M Mackerel, Indian, 15 Madagascar, 80 Malacca, Straits of, 80, 228 Malaria, mosquito carriers of, 151, 158 Mammals living within mangals, 157 not specialized, 181 Mangals, 75, 80, 83, 85, 88, 94, 97, 108, 110, 111, 114, 117, 120, 193, 207, 233 clearing of, 123 distribution of marine fauna in, 152, 165-1 8 1 effect of currents on, 136 environment provided by, 150 fauna of, 150-181, 221, 231 fresh water supplies, 118 fully zoned, 135 land animals in, 153 landward fringe of, 91-103 mammals in, 157 mineral content of water in, 211 of Sarawak, 84 rain forest, 93 reclamation of, 240-241 seaward fringe of, 112-1 17 soils of, 121 specializations of fauna of, 181-219
SUBJECT INDEX
Mangals-continued variations in zones of, 118 waterways in, 133 zonation of animals in, 165 zones of, 91 Mangrove forests, 74, 80, 92, 101, see also Mangals clear-felling of, 237 management of, 235, 236, 237 of island reefs, 120 “Mangrove Kingfishers”, 153 “Mangrove Park”, 119, 120, 121 Mangrove swamps, 74, 75, 85 northern limits in eastern Asia, 220 popular idea of, 108 soils of, 122, 123 Mangrove swimming crab, 2 14-2 17 as food, 240 burrows of, 214 distribution of, 215 habitats, 216 mating of, 216 moulting and growth of, 216 Mangrove timber, 234 as firewood, 235, 236 corrosion of iron in Sonnerazia, 234 for charcoal production, 235 for decorative use, 234 for pulping, 237 for structuraluse, 234 in cabinet work, 234 in piling, 234 in shipbuilding, 77, 233 susceptibility t o shipworm attack, 234 termite resistance of, 234 use in houses, 234 weight of, 236 Mangrove zonation control of, 124-136 interruptionin, 130 relationship with intertidal levels, 129 Mangroves, 74, 80, 85, 99, 112, 129, 152, 232 “antlered”, 108 as source of timber, 77, 233 biogeographical comment on, 222233 coastlines where found, 78
401
Mangroves-continued complete succession of, 130 distribution of species, 90, 95, 98, 100, 104,facing 104, 119, 127, 132 extratropical extensions of, 219-222 frosts, effects of, 221 geographical distributionof, 219-233 geological history of, 85 geological significance of, 82-85 greatest luxuriance,219 historical references to, 76-77 latitudinal limits of, 134 north-easternextensions of, 230 origin of word, 75 penetration in estuaries, 82 preferring shade, 150 preferring sunlight, 148 relation between root and shoot systems, 144 salinity tolerance of, 131 shallow rooted, 136 shrubs, 103 southernmost occurrence of, 220 specializations of stems and leaves, 140 spread of, by seaborne seeds, 224 succession of, 148-150 temperature limits of, 221 viviparous, 145 zonation of, 89-136 Margin of subtraction, 232 Marine animals pattern of behaviour, 184 rhythmic activity of, 185 specialization of, 184 Marine fishery resources, latent, 4 Marshall Islands, 233 Massawa, Bay of, 220 Mating of pelagic chaetognaths,334 of Sagitta, 329 of Spadella cephaloptera, 323-324, 325, 327 Maturation prophase, 304 Maturation spindles, 339 Maxillipeds, 202, 203, 204-205, 209, 213 Meiosis, 309 Mesodermal elements, 303 Metaphase, spermatogonial, 310
402
SUBJECT INDEX
Microncsia, mangaIsof, 233 Micropilar apparatus, 298 Midges, 160 Milk fish, 238 Moqambique, 84, 92, 101, 116, 131 Moluccas, 230 Molluscs, 75, 151, 173, 176, 217-219 distribution of fresh-water,230 fccding of, 218 fossil, 230 Monkeys, 157, 237 Morisoori effects, 219 Moretori Bay, 220 Mosqnit,oes, 151, 158, 159, 195 associated with Anstralian mangroves, 159 larvae, in saline waters, 184 Mouse doer, 157 Muck soils, 121 Mud adaptation of plants to, 136-140 fauna of, 201 in mangrove aroas, 83, 118 Mud lobster, 121, 169, 175 burrows of, 169, 208 digging technique, 209 feeding, 209 modification of substratum by, 175 mounds of, see Thalassina mounds Mud-skippers, 113, 179, 181, 185-200 aggressive behaviour of Periophthalmus chrysospilos, 179, 192 burrows of, 180, 187, 188, 190, 191, 193 confrontation, 192, 194 “crutching”, 195, 196, 197 defence display of, 192 distraction display of, 193 eyes of, 197-198 feeding, 199 “grazing” on mud, 190 locomotion 011 land, 195- 197 nest pools of, 189 sexual display of, 192 skimming on water, 197 skipping, 195 swimming behaviour of, 195 territorial behaviour of, 190, 191 tree-climbing by, 195, 197 water-exchangemechanism, 199
Mud-skippers~continued with fused pelvic fins, 185, 186 within mangals, 186 Mullet, 239
N Nervous fibrillae, 275 Net economic yield from fishing, 52, 53 New Britain, fauna of, 231 New Caledonia, fauna of, 231 New Guinea, 82, 223, 231 New Hebridcs, fauna of, 231 New South Wales, 220 New Zealand, mangroves in, 219, 220, 222 Nibong palm, 99 uses of, 237-238 Nitrifying bacteria, 122 North Atlantic, overfishing in, 14 North-East Atlantic Fisheries Commission, 40, 41, 42, 43 North Pacific Fur Seal Commission, 41, 42, 43-44 North Sea, fishing in, 9, 10, 24, 25, 46 Northern hemisphere, mangroves in, 221 Nuclear net, 311, 312, 316, 322 Nursery areas for fish, 27, 45 Nypa association, 85, 88, 97, 125, 133 uses t o man, 97 Nypa palm, uses of, 237
0 Offshore waters, 35 lack of uniformity in delimiting, 37 Oman, Gulf of, 233 Oocytes, of chaetognaths, 292, 293, 294, 295, 298, 300, 301, 302, 304, 305, 307, 308, 312 dimensions, of, 313 growth of, 31 1 Oogenesis in chaetognaths, 31 1 Oogonia, 295, 301, 303, 304 Oospermaduct, 292, 293 Opercularmovements, 198 Osmotic pressure, 142 of halophytes, 141 Otters, 157
403
SUBJECT INDEX
Ovaries, of chaetognaths, 292, 293, 295, 296, 300, 302 development of, in Spudella, 303 endothelium of, 293, 300 germinal epithelium of, 292 in Eukrohnia, 309 in Pterosagitta, 306 in Sagitta, 294, 338 in Spadella, 300, 304 Overfishing, 3, 9 in North Atlantic, 14 need for biological approach to, 6 problems of, 6 Oviduct, temporary, of chaetognaths, 295, 335, 336, 337, 338, 339, 342 Oysters, 117
P Pacific fisheries in eastern, 17 fisheries in northern, 1 3 North, 37 Pacific islands, 232 Passerine birds, 156 Pelagic species, 12 Permanent Commission for the South Pacific, 42 Persian Gulf, 233 Pes-caprac association, 87, 88 Photo-receptors, 273, 364 Photosensitivity, 274 control of vertical distribution of Sagitta c r a ~ s aby, 274 Phototactic movement, 274 Phragmatic structure, 280 Pigeons, 155 Plaice, 2, 3, 10, 28 North Sea stocks, 9 Plant associations of sea-shore, 85 Barringtonia, 87, 88, 89, 96, 125, 133, 225 Rruguiera cylindrica, 107 Bruguiera gymnorhiza, 107 Cymoclocea, 88 Lumnitzera littorea, 93 mangal, 85 Nypa, 85, 88, 97, 125 Pes-caprae, 87, 88 Saltwort, 88, 89 Xylocarpus-Heritiera, 107
Pncumatophores, 129, 138, 172 form of, 139 functions of, 139 Pollen analysis, 85 Polymorphism, 346 Polyplasts, 291 movements of, 291 Pools, 176 Prawns, 75, 122, 123, 177, 200 as food, 2, 240 cultivation of, 240 penaeid, 217, 240 Prop roots, 121, 136, 137, 140, 167, 177, 208, 236 Protandric hermaphroditss, 330 Protein intake contribution of fish to, 2, 5 total, 5 Purse seines. 27
Q Queensland, 94, 96, 126, 223, 231 mangrove distribution in, 95, 100, 104, 119, 127
R Rainfall, seasonal, 232 Rayon production from mangrove timber, 237 Red Sea, 220 Redfish, 3 Redshank, 155 Regeneration of mangal, 128 Regeneration studies on Sagitta, 354 on Spadella cephaloptera, 352-354 Regional Fisheries Advisory Commission for the South-West Atlantic, 40 Regional Fisheries Commission for West Africa, 40 Reptiles, 156, 181 Respiratory epithelia, in mud-skipper, 198 Rhizophora forests, 108-111, 125, 129 fauna of, 177 in fresh-water areas, 111 in salt-water areas, 111 soil in, 111
404
SUBJECT INDEX
Rivers, in mangal, 133 Rooting systems, 175 of Avicennia spp., 137, 138 of Ceriops spp., 137, 138 of Rhizophora spp., 137, 140 of Sonneratia spp., 137, 138 of Xylocarpus spp., 137, 140 Rosewood, 234 Rot holes, in branches, 151 Ryii-Kyfi archipelago, 220, 221, 222
S Sahul Shelf, 84, 232 St. Vincent Gulf, 220 Salinity ability of animals to adjust to varia tion in, 184 of soil water, 89, 101, 118, 121, 124, 131 Salmon, 3, 5, 55 fishery on high seas, 48 North American Pacific, 30, 48 Salt content of Sonneratia wood, 142, 234 Salt excretion, 142 Salt flats, 232 Salt marsh, 80 compared with mangrove shore, 81 Salt pans, 182, 241 Salt production technique in humid tropics, 241 Salt-secretingglands of plants, 131, 142, 143, 144 of reptiles, 181 “Salt wcdge”, 82 “Salting cliff”, 80, 93, 128, 181 Saltwort association, 88, 89 Sand dunes, 77 Sandakan, distribution of mangroves at, 98 Sarawak, 84, 94, 116 Sardine, 3, 15, 18 Scaphognathite, 203 Schorre, 80, 81, see also Salt marsh Sea bream, 8 Sea eagles, 154 Sea-going craft, 233 Sea otters, 37 Sea snakes, 226
Seaward fringe of mangal, 112-117,120 factors affecting fauna of, 177-178 fauna of accrescent shores, 178-181 fauna of eroding shores, 181 Sonneralia zone of, 115 Seeds viability of, 224 Seedlings of mangrove species, 146 colonization by, 149 Scminal ampullae, in chaetognaths, 305, 306, 308 Scminal pouch, in chaetognaths, 293, 295, 296, 297, 298, 301, 302, 303, 304, 305, 306, 308, 312 endothelium of, 293 glandular cells of, 307 possible trophic function of, 312 Seminal receptacle, in chaetognaths, 294, 301, 302, 303, 304, 306, 323, 324, 326, 341 Seminal vesicles, in chaetognaths,290, 291, 323, 330, 331, 332 Shade and sun conditions, effect on animals, 152 Shark Bay, 220 Shellfish, 2 “Shelter wood” system, 236 Ships, use of mangrove timber in, 77, 233 Shoaling fish, 32 Shore level, alteration of, 84 Shore lines, reorganization of, 136 Shore profile, 126 flats in, 126 Silt, 83 encouraging deposition of, 150 Silvicultural rotation, 236 Sinai peninsula, 130, 220 Size limits for fishery regulations, 26, 34 Slash, from forestry operations, 237 disposal of, 237 Snails, 165, 168, 174, 177, 180 as food, 240 neritid, 75 pulnionate, 75 purple dye produced by, 180 submarine, 2 19 Snakes, 156, 180 of Indo-Malayanregion, 229
405
SUBJECT INDEX
Sofala Shelf, 84 Soil animals living in, 151 fertility of, 178 in mangrove swamps, 122 in rhizophora forests, 111 surface of, 151, 174 waterlogging of, 124, 129, 133, 134 Soil levels, raising of, 107 Soil water, salinity of, 89, 101, 118, 121, 124, 131 Soils, 94 colour, 123 compacting of, 129 degradation of, 124 flow of, 129 hydrogen sulphide content, 121, 139 of mangals, 121 oxygen content of, 121 rapid deposition of, 122 Sole, 2, 28, 46 Solomon Islands, fauna of, 231 Spencer Gulf, 220 Spermatheca, in Sugitta, 294 Spermatogenesis, 290, 291 in chaetognaths, 309-31 1 Spores of ferns, 148 Stock and recruitment in fisheries relationships, 19 theoretical models, 19 Stomata of mangroves, 141 Suction pressure, 142, 144 Sulphate reducing bacteria, 122, 123 Sulphur bacteria, 122 Sumatra, 82, 83 Sunda Shelf, 84, 228, 229 Sundabans, 96 Sundaland, pleistocene subcontinent, 226, 227 importance of, 228 Sustainableyield, 16 Sydney, 220 mangrove fauna at, 221
T Tadpoles, 177, 181 induction of metamorphosis, 182 Tambaks, see Fish ponds Tannins, 237
Teeth, of chaetognaths, 274, 279 Telmun, 233 Temperature limits of mangroves, 221 upper lethal of crabs, 209, 210 Terek sandpiper, 155 Territorial seas, 35, 36, 37 Testes, of chaetognaths, 290 Thalassina mounds, 97, 107, 108, 121, 148, 169, 170, 175, 200 Tidal flooding, frequency of, 124, 125 Tidal range, 124 Tidal wave, 82 Tide, connection with animal rhythms, 155 Tilapia culture, 239 and malarial control, 239 unpopularity in rice-growing countries, 239 Transpiration rates, of mangroves, 141, 144 Transverse septum, in chaetognaths, 272, 290 Trawlers factory, 10, 13 freezer, 10, 11, 13 steam, 7 Trawls, mesh regulation, 27, 28, 46, 47 Tree canopy, 150 Tuna, yellowfin, 17, 44
U Undergrowth, 110 United Nations Conference on the Law of the Sea of 1958, 35, 38, 39, 40, 45 of 1960, 35, 36 Upper lethal temperatures for crabs, 209, 210
V Vagina, of chaetognaths,302, 306, 307, 308, 340, 341, 342, 343 Viraemias mosquito carriers of, 151 reservoir hosts of, 157 Vitelline membrane, of Spadella egg, 320
406
SUBJECT INDEX
Vitellogcnesis, in chactognaths, 293, 312 Viviparity in mangrovcs, 145
w Waders, 154, 155 “Wallace’s Line”, 84, 228 Wastage of resources, 55 Water storage tissue of mangroves, 141 Weighting factors for fishing quotas, 34 Western Indian Ocean, 223, 225 fauna of, 225 Wertcrn Point Bay, 220, 221 Whales, 8, 49 Antarctic, 18 blue, 8, 32 conservation of, 55 fin, 8, 32 gray, 8 right, 8 sol, 32 Whaling agreement on Antarctic, 53 Antarctic, 29, 32, 33, 44-45, 48 blue whale unit (BWU), 34 lack of success of regulation, 48
Whaling-continued size limits for, 46 violations of regulations in, 46 “Whaling olympics”, 45 Whimbrel, 155 Whiting, 28 blue, 15 Wild pigs, 157 Woodpeckers, 155 World production of fish, 1, 2 marine, 3
X Xylocarpus-Heriticrnassociation, 107
Y Yaeyama Islands, 220, 221 Year-classes, 10 Yellowtail, 2 Yield from a fishery, 52 curves of, 20
Z Zambezi river, 80, 82, 96 Zonation, see mangroves