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Influence of climatic changes on the parasites of Atlantic cod Gadus morhua off coastal Labrador, Canada

Published online by Cambridge University Press:  12 April 2024

R.A. Khan  and
C.V. Chandra
R.A. Khan*
Affiliation:
Department of Biology and Ocean Sciences Centre, Memorial University of Newfoundland, St John's, Newfoundland, Canada, A1B 3X9
C.V. Chandra
Affiliation:
Department of Biology and Ocean Sciences Centre, Memorial University of Newfoundland, St John's, Newfoundland, Canada, A1B 3X9
*
*Fax: 709 737 3220 E-mail:rakhan@mun.ca
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Abstract

A study was conducted in 2000 and 2003, following the collapse of the commercial fishery in 1990, to compare metazoan parasites of Atlantic cod Gadus morhua, captured off coastal Labrador, with samples taken in 1980 and 1986. Fish were captured by otter trawl offshore in the North Atlantic Fish Organisation subarea 2J. Parasites were removed from the digestive tract, stained, identified and compared between the different groups. Both the prevalence and mean abundance of trematodes, larval nematodes and E. gadi were significantly lower in fish taken in 2000 and 2003 than in 1980. While mean values of trematodes and nematodes declined in 1986, those of Echinorhynchus gadi remained unchanged in 1986 and 1990. Four-year-old cod sampled in 1990 harboured significantly fewer E. gadi than older age groups. The most commonly occurring trematodes included Podocotyle reflexa, Lepidapedon elongatum, Derogenes varicus and Hemiurus levinseni while the larval nematode, Anisakis sp. was predominant. Comparison of offshore samples taken in 2000 and 2003 with others taken in previous years suggests an overall decline of parasites coincident with a change in climatic conditions, the absence of a major food source, namely capelin Mallotus villosus, of cod and ultimately the decline of the Labrador population.

Type
Research Article
Information
Journal of Helminthology , Volume 80 , Issue 2 , June 2006 , pp. 193 - 197
Copyright
Copyright © Cambridge University Press 2006

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References

Appy, R.G. & Burt, M.D.B. (1982) Metazoan parasites of cod, Gadus morhua, L. in Canadian Atlantic waters. Canadian Journal of Zoology 60, 1573–1579.CrossRefGoogle Scholar
Brattey, J., Bishop, C.A. & Myers, R.A. (1990) Geographic distribution and abundance of Pseudoterranova decipiens (Nematoda: Ascaroidea) in the musculature of Atlantic cod, Gadus morhua from Newfoundland and Labrador. Canadian Bulletin of Fisheries and Aquatic Sciences 222, 67–82.Google Scholar
Bush, A.O., Lafferty, K.D., Lotz, J.M. & Shostak, A.W. (1997) Parasitology meets ecology on its own terms: Margolis et al. revisited. Journal of Parasitology 83, 575–581.CrossRefGoogle Scholar
Carscadden, J.E., Frank, K.T. & Leggett, W.C. (2002a) Ecosystem changes and the effects on capelin (Mallotus villosus), a major forage species. Canadian Journal of Fisheries and Aquatic Sciences 58, 73–85.CrossRefGoogle Scholar
Carscadden, J.E., Montevecchi, W.A., Davoren, G.K. & Nakashima, B.S. (2002b) Trophic relationships among capelin (Mallotus villosus) and seabirds in changing ecosystem. ICES Journal of Science 59, 1027–1033.CrossRefGoogle Scholar
Chandra, C.V. & Khan, R.A. (1988) Nematode infestation of fillets from Atlantic cod, Gadus morhua, off eastern Canada. Journal of Parasitology 74, 1038–1040.CrossRefGoogle ScholarPubMed
Cross, T.F. & Payne, R.H. (1978) Geographic variation in Atlantic cod, Gadus morhua, off eastern North America: a biochemical systematics approach. Journal of the Fisheries Research Board of Canada 35, 117–123.CrossRefGoogle Scholar
Dempson, J.B., Shears, M. & Bloom, M. (2002) Spatial and temporal variability in the diet of anadromous Arctic charr, Salvelinus alpinus, in northern Labrador. Environmental Biology of Fishes 64, 49–62.CrossRefGoogle Scholar
Drinkwater, K.F. (2004) Atmospheric and sea-ice conditions in the Northwest Atlantic during the decade 1991–2000. Journal of the Northwest Atlantic Fisheries Science 34, 1–11.CrossRefGoogle Scholar
Hemmingsen, W. & MacKenzie, K. (2001) The parasite fauna of the Atlantic cod, Gadus morhua L. Advances in Marine Biology 40, 1–80.CrossRefGoogle Scholar
Khan, R.A. & Thulin, J. (1991) Influence of pollution on parasites of aquatic animals. Advances in Parasitology 30, 201–238.CrossRefGoogle ScholarPubMed
Khan, R.A. & Tuck, C. (1995) Parasites as biological indicators of stocks of Atlantic cod (Gadus morhua) off Newfoundland, Canada. Canadian Journal of Fisheries and Aquatic Sciences 52, 195–201.CrossRefGoogle Scholar
Lee, E.M. & Khan, R.A. (2000) Length–weight–age relationships, food, and parasites of Atlantic cod (Gadus morhua) off coastal Labrador within NAFO Division 2H and 2J–3K. Fisheries Research 45, 65–72.CrossRefGoogle Scholar
Lilly, G.R. (1984) Annual variability in the diet of Atlantic cod (Gadus morhua L.) off southern Labrador and northeast Newfoundland (Div. 2J p3K) in autumn, 1977–82. North Atlantic Fisheries Organisation Science Council Report. Document 84/VI/79, Serial No. N868, 18 pp.Google Scholar
Lilly, G.R., Almeida, M.A. & Lear, W.H. (1984) Food of Atlantic cod (Gadus morhua) from southern Labrador and eastern Newfoundland (div. 2J, 3K, and 3L) in winter. North Atlantic Fisheries Organisation Science Council Report. Document 84/VI/88, Serial No. N878, 9 pp.Google Scholar
Lilly, G.R., Parsons, D.G. & Kulka, D.W. (2000) Was the increase in shrimp biomass on the northeast Newfoundland shelf a consequence of a release in predation pressure from cod? Journal of the Northwest Atlantic Fisheries Science 27, 45–61.CrossRefGoogle Scholar
Mackenzie, K. (1983) Parasites as biological tags in fish population studies. Advances in Applied Biology 7, 251–331.Google Scholar
McClelland, G., Misra, R.K. & Mortell, D.J. (1990) Larval anisakine nematodes in various fish species from Sable Island Bank and vicinity. Canadian Bulletin of Fisheries and Aquatic Sciences 222, 83–113.Google Scholar
Morris, C.J. & Green, J.M. (2002) Biological characteristics of a resident population of Atlantic cod (Gadus morhua, L.) in southern Labrador. International Commission for Exploration of the Sea Journal of Marine Science 59, 666–678.Google Scholar
Polyansky, Y.I. (1955) Data on fish parasitology of the northern seas of the USSR. Trudy Zoologicheskogo Instituta Akademiya Nauk SSSR. 158 pp.Google Scholar
Rose, G.A., O'Driscoll, R.L. (2002) Capelin are good for cod: can the northern stock rebuild without them? International Commission for Exploration of the Sea Journal of Marine Science 59, 1018–1026.Google Scholar
Ruzzante, D.E., Wroblewski, J.S., Taggart, C.T., Smedbol, R.K., Cook, D. & Goddard, S.V. (2000) Bay-scale population structure in coastal Atlantic cod in Labrador and Newfoundland, Canada. Journal of Fish Biology 56, 431–447.Google Scholar
Templeman, W. (1974) Migration and intermingling of Atlantic cod, Gadus morhua, stocks of the Newfoundland area. Journal of the Fisheries Research Board of Canada 31, 1073–1092.CrossRefGoogle Scholar
Valtonen, E.T., van Maren, M.J. & Timola, O. (1983) A note on the intermediate hosts of Echinorhynchus gadi Zoega, in Muller (Acanthocephala) in the Baltic Sea. Aquilo Series (Zoology) 22, 93–97.Google Scholar