Cookies Policy
X

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies.

I accept this policy

Find out more here

Changes in Density, Age Composition, and Growth Rate of Portunus Pelagicus in a Large Embayment in Which Fishing Pressures and Environmental Conditions Have Been Altered

No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
The full text of this article is not currently available.

Brill’s MyBook program is exclusively available on BrillOnline Books and Journals. Students and scholars affiliated with an institution that has purchased a Brill E-Book on the BrillOnline platform automatically have access to the MyBook option for the title(s) acquired by the Library. Brill MyBook is a print-on-demand paperback copy which is sold at a favorably uniform low price.

Access this article

+ Tax (if applicable)
Add to Favorites
You must be logged in to use this functionality

image of Journal of Crustacean Biology

Abstract Commercial and recreational catches of the blue swimmer crab Portunus pelagicus in Cockburn Sound, a large marine embayment on the west coast of Australia, have risen markedly over the last 20–30 years. However, because commercial fishers changed from using tangle nets to traps to catch crabs during this period, the annual catch per unit effort data for the commercial fishery throughout this period are not directly comparable and cannot thus be used to elucidate whether the increased catches reflected an increase in crab density. Trawling was thus undertaken to estimate the densities of P. pelagicus in Cockburn Sound in the late 1990s to facilitate comparisons with those we estimated from trawl catch rates for this species in that embayment during the early 1970s. The comparisons demonstrate that, despite increases in commercial and recreational crab catches, the densities of P. pelagicus in Cockburn Sound have risen markedly between the above two periods. This change is probably related to a decline in the abundance of the large piscivorous predators of P. pelagicus as a result of heavy fishing pressure and possibly also to an increase in the abundance of the prey of this portunid. Size composition data demonstrate that appreciable numbers of crabs survived in Cockburn Sound until the end of their second year of life and even beyond during the early 1970s, whereas the vast majority of 1+ crabs were removed by heavy fishing pressure by the month (June) that they had reached 18 months in age in the late 1990s. The fact that, in the late 1990s, few legal-sized crabs still remained for fishing between July and December and the 0+ age class increased in number and size throughout the year accounts for the broad estimates of biomass becoming far greater in these months in the 1990s than in the corresponding months in the early 1970s. Growth during the first eleven months of life, i.e., in the period leading up to the age at which crabs reach the minimum legal size for retention, was significantly faster in the early 1970s than in the late 1990s when crab densities were much greater. The slower growth rate and the reduced longevity through heavy fishing pressure in the latter period would help account for females becoming mature at a smaller size and for ovigerous females being represented by one rather than two substantial size cohorts, respectively. The essentially single size cohort in the late 1990s and first cohort in the early 1970s correspond mainly to crabs in their first maturity instar, whereas the second cohort in the early 1970s predominantly represented crabs in their second maturity instar.

Affiliations: 1: Centre for Fish and Fisheries Research, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia (corresponding author (SdL): simond@central.murdoch.edu.au; others: normhall@central.murdoch.edu.au; i-potter@possum.murdoch.edu.au)

Loading

Full text loading...

/content/journals/10.1651/c-2376
Loading

Data & Media loading...

1. Bailey R. 1982. The relationship between catches of snow crab, Chionoecetes opilio (O. Fabricus) and abundance of cod (Gadus morhua L.) in the southwestern Gulf of St. Lawrence. Pp. 283498 in Proceedings of the International Symposium on the Genus Chionoecetes, May 36, 1982. Lowell Wakefield Fisheries Symposia Series
2. Cerrato R. M. 1990 "Interpretable statistical tests for growth comparisons using parameters in the von Bertalanffy equation." Canadian Journal of Fisheries and Aquatic Sciences Vol 47 1416 1426
3. Christensen V. 1998 "Fishery-induced changes in a marine ecosystem: insight from models of the Gulf of Thailand." Journal of Fish Biology Vol 53 128 142
4. Cobb J. S. 1986 "Summary of session 6: Ecology of population structure." Canadian Journal of Fisheries and Aquatic Sciences Vol 43 2389 2390
5. de Lestang S. , Platell M. E. , Potter I. C. 2000 "Dietary composition of the blue swimmer crab Portunus pelagicus L. Does it vary with body size and shell state and between estuaries?." Journal of Experimental Marine Biology and Ecology Vol 246 241 257
6. de Lestang S. , de Lestang S. , Hall N. , Potter I. C. 2003a "Do the age compositions and growth of the crab Portunus pelagicus in marine embayments and estuaries differ?." Journal of the Marine Biological Association of the United Kingdom Vol 83 1 8
7. de Lestang S. , de Lestang S. , Hall N. , Potter I. C. 2003b "Reproductive biology of the blue swimmer crab, Portunus pelagicus (Decapoda: Portunidae), in five water bodies on the west coast of Australia." Fishery Bulletin (U.S.) Vol 101 745 757
8. Department of Fisheries, Western Australia. 2002. Protecting and sharing Western Australia's coastal fish resources. 1st October 2002.
9. Etherington L. L. , Eggleston D. B. 2000 "Large-scale blue crab recruitment: linking postlarval transport, post-settlement planktonic dispersal, and multiple nursery habitats." Marine Ecology: Progress Series Vol 204 179 198
10. Food and Agriculture Organisation. 2000. FAO Yearbook. Fisheries Statistics. Capture Production, 86/1, FAO, Rome
11. Hanumara R. C. , Hoenig N. A. 1987 "An empirical comparison of a fit of linear and non-linear models for seasonal growth in fish." Fisheries Research Vol 5 359 381
12. Hutchins J. A. 2001 "Influence of population decline, fishing and spawner variability of the recovery of marine fishes." Journal of Fish Biology Vol 59 306 322
13. Ingles J. , Braum E. 1989 "Reproduction and larval ecology of the blue swimming crab Portunus pelagicus in Ragay Gulf, Philippines." Internationale Revue der gesamten Hydrobiologie Vol 74 471 490
14. Jernakoff P. , Fitzpatrick J. , Phillips B. F. , De Boer E. 1994 "Density and growth in populations of juvenile western rock lobsters, Panulirus cygnus (George)." Australian Journal of Marine and Freshwater Research Vol 45 69 81
15. Jones M. B. , Simons M. J. 1983 "Latitudinal variation in reproductive characteristics of a mud crab, Helice crassa (Grapsidae)." Bulletin of Marine Science Vol 33 656 670
16. Kailola P. J. , Williams M. J. , Stewart P. C. , Riechelt R. E. , McNee A. , Grieve C. 1993. Australian Fisheries Resources. Bureau of Resource Sciences, Canberra
17. Kendrick G. A. , Aylward M. J. , Hegge B. J. , Cambridge M. L. , Hillman K. , Wyllie A. , Lord D. A. 2002 "Changes in seagrass coverage in Cockburn Sound, Western Australia between 1967 and 1999." Aquatic Botany Vol 73 75 87
18. McGarvey R. , Ferguson G. J. , Prescott J. H. 1999 "Spatial variation in mean growth rates at size of southern rock lobster, Jasus edwardsii, in South Australian waters." Marine and Freshwater Research Vol 50 333 342
19. Merrick R. L. 1997 "Current and historical roles of apex predators in the Bering Sea ecosystem." Journal of Northwestern Atlantic Fisheries Science Vol 22 343 355
20. Morrissy N. M. , Bird C. , Cassells G. 1995. Density-dependent growth of cultured marron, Cherax tenuimanus (Smith 1912).Freshwater Crayfish-10. Tenth International Symposium of Astacology: 280298
21. Penn J. W. 1977 "Trawl caught fish and crustaceans from Cockburn Sound." Department of Fisheries and Wildlife, Western Australia, Report No Vol 20 24
22. Pollock D. E. 1995 "Changes in maturation ages and sizes in crustacean and fish populations." South African Journal of Marine Science Vol 15 99 103
23. Polovina J. J. 1989 "Density dependence in spiny lobster, Panulirus marginatus, in the northwestern Hawaiian Islands." Canadian Journal of Fisheries and Aquatic Sciences Vol 46 660 665
24. Potter I. C. , Chrystal P. J. , Loneragan N. R. 1983 "The biology of the blue manna crab Portunus pelagicus in an Australian estuary." Marine Biology Vol 78 75 85
25. Schnute J. , Fournier D. A. 1980 "A new approach to length-frequency analysis: growth structure." Canadian Journal of Fish and Aquatic Science Vol 37 1337 1351
26. Steckis R. A. , Potter I. C. , Lenanton R. C J. 1995. The commercial fisheries in three southwestern Australian estuaries exposed to different degrees of eutrophication. Pp. 189203 in A. J. McComb, ed. Eutrophic Shallow Estuaries and Lagoons. CRC Press, Boca Raton, Florida
27. Stevens J. D. , Bonfil R. , Dulvy N. K. , Walker P. A. 2000 "The effects of fishing on sharks, rays and chimaeras (chondrichthyans), and the implications for marine ecosystems." Journal of Marine Science Vol 57 476 494
28. Stephenson W. 1962. The evolution and ecology of portunid crabs, with especial reference to Australian species. Pp. 3467 in G. W. Leeper, ed. The Evolution of Living Organisms. Melbourne University Press, Melbourne, Australia
29. Sukumaran K. K. , Neelakantan B. 1997 "Age and growth in two marine portunid crabs, Portunus (Portunus) sanguinolentus (Herbst) and Portunus (Portunus) pelagicus (Linnaeus) along the southwest coast of India." Indian Journal of Fisheries Vol 44 111 131
30. Sumner N. R. , Williamson P. C. 1999. A 12-month survey of coastal recreational boat fishing between Augusta and Kalbarri on the west coast of Western Australia during 199697. Fisheries Research Report, No. 117. 52 pp
http://brill.metastore.ingenta.com/content/journals/10.1651/c-2376
Loading

Article metrics loading...

/content/journals/10.1651/c-2376
2003-01-01
2016-12-05

Sign-in

Can't access your account?
  • Tools

  • Add to Favorites
  • Printable version
  • Email this page
  • Subscribe to ToC alert
  • Get permissions
  • Recommend to your library

    You must fill out fields marked with: *

    Librarian details
    Your details
    Why are you recommending this title?
    Select reason:
     
    Journal of Crustacean Biology — Recommend this title to your library
  • Export citations
  • Key

  • Full access
  • Open Access
  • Partial/No accessInformation