Abstract
We present evidence of a largely undocumented environmental effect of coastal sea-cage fish farms on wild fish. We estimated the total abundance and biomass of wild fish aggregated in the immediate vicinity of nine fish farms in the Mediterranean Sea and one farm off the east coast of Australia. Estimates of wild fish aggregations ranged from 2000 to 86000 individuals and from 100 kg to 38.5 tons of fish per farm and were always greater than control locations. Particularly large aggregations (>30000 fish, > 12 tons) occurred at half of the farms. Aggregations were temporally stable for weeks to months and most wild fish associated with farms (88%) were of adult size. Potential effects of such large aggregations of wild fish in the immediate vicinity of fish farms include increased vulnerability to fishing and pathogen transfer between caged and wild fish. We suggest specific legislation should be enacted wherever large aggregations of wild fish occur around fish farms to enhance the positive and reduce the negative effects of association.
Similar content being viewed by others
References
Bayle, J. T., C. Valle & A. Verdù, 2002. EcoCEN: application for managing fish visual counts. Informes y estudios COPEMED, no. 7.
Bjordal, A. & A. B. Skar, 1992. Tagging of saithe (Pollachius virens L.) at a Norwegian fish farm: preliminary results on migration. ICES Council Meeting Papers 1992/G: 35.
Bjorn, P. A., B. Finstad & R. Kristoffersen, 2001. Salmon lice infection of wild sea trout and Arctic char in marine and freshwaters: the effects of salmon farms. Aquaculture Research 32: 947–962.
Carss, D. N., 1990. Concentrations of wild and escaped fishes immediately adjacent to fish farm cages. Aquaculture 90: 29–40.
Castro, J. J., J. A. Santiago & A. T. Santana-Ortega, 2002. A general theory on fish aggregation to floating objects: an alternative to the meeting point hypothesis. Reviews in Fish Biology and Fisheries 11: 255–277.
Chiappone, M. & S. Sullivan, 2000. Marine reserve design criteria and measures of success: lessons learned from the Exuma Cays Land and Sea Park, Bahamas. Bulletin of Marine Science 66: 691–705.
Crozier, W., 2000. Escaped farmed salmon, Salmo salar L., in the Glenarm River, Northern Ireland: genetic status of the wild population 7 years on. Fisheries Management and Ecology 7: 437–446.
Dempster, T., P. Sanchez-Jerez, J. T. Bayle-Sempere, F. Giménez-Casalduero & C. Valle, 2002. Attraction of wild fish to sea-cage fish farms in the south-western Mediterranean Sea: spatial and short-term temporal variability. Marine Ecology Progress Series 242: 237–252.
Freon, P. & L. Dagorn, 2000. Review of fish associative behaviour: toward a generalisation of the meeting point hypothesis. Reviews in Fish Biology and Fisheries 10: 183–207.
Gausen, D. & V. Moen, 1991. Large-scale escapes of farmed Atlantic salmon Salmo salar into Norwegian rivers threaten natural populations. Canadian Journal of Fisheries and Aquatic Science 48: 426–428.
Harmelin-Vivien, M., J. Harmelin, C. Chauvet, C. Duval, R. Galzin, P. Lejuene, G. Barnabe, F. Blanc, R. Chevalier, J. Duclerc & G. Lasserre, 1985. Evaluation visuelle des pueplements et populations de poissons. Methodes et problemes. Revue D Ecologie 40: 467–539.
Josse, E., L. Dagorn & A. Bertrand, 2000. Typology and behaviour of tuna aggregations around fish aggregating devices from acoustic surveys in French Polynesia. Aquatic Living Resources 13(4): 183–192.
Katz, T., B. Herut, A. Genin & D. L. Angel, 2002. Gray mullets ameliorate organically enriched sediments below a fish farm in the oligotrophic Gulf of Aqaba (Red Sea). Marine Ecology Progress Series 234: 205–214.
McClanahan, T. & S. Mangi, 2000. Spillover of exploitable fishes from a marine park and its effect on the adjacent fishery. Ecological Applications 10: 1792–1805.
Naylor, R., R. Goldburg, J. Primavera, N. Kautsky, M. Beveridge, J. Clay, C. Folke, J. Lubchenco, H. Mooney & M. Troell, 2000. Effect of aquaculture on world fish supplies. Nature 405: 1017–1024.
Sanchez-Mata, A. & J. Mora, 2000. A review of marine aquaculture in Spain: production, regulations and environmental monitoring. Journal of Applied Ichthyology 16: 209–213.
Theodorou, J., 1999. Greece focuses on marketing seabass and seabream. Seafood International 14: 35–36.
Volpe, J. P., E. B. Taylor, D. W. Rimmer & B. W. Gluckman, 2000. Evidence of natural reproduction of aquaculture-escaped Atlantic salmon in a coastal British Columbia river. Conservation Biology 14: 899–903.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Dempster, T., Sanchez-Jerez, P., Sempere, J.B. et al. Extensive Aggregations of Wild Fish at Coastal Sea-Cage Fish Farms. Hydrobiologia 525, 245–248 (2004). https://doi.org/10.1023/B:HYDR.0000038870.13985.0f
Issue Date:
DOI: https://doi.org/10.1023/B:HYDR.0000038870.13985.0f