Long-term changes in the trophic level of the Celtic Sea fish community and fish market price distribution
Article first published online: 13 JUN 2002
Journal of Applied Ecology
Volume 39, Issue 3, pages 377–390, June 2002
How to Cite
Pinnegar, J. K., Jennings, S., O’Brien, C. M. and Polunin, N. V. C. (2002), Long-term changes in the trophic level of the Celtic Sea fish community and fish market price distribution. Journal of Applied Ecology, 39: 377–390. doi: 10.1046/j.1365-2664.2002.00723.x
- Issue published online: 13 JUN 2002
- Article first published online: 13 JUN 2002
- Received 15 May 2001; final copy received 22 February 2002
- stable isotope
- 1The intensive exploitation of fish communities often leads to substantial reductions in the abundance of target species, with ramifications for the structure and stability of the ecosystem as a whole.
- 2We explored changes in the mean trophic level of the Celtic Sea (ICES divisions VII f–j) fish community using commercial landings, survey data and estimates of trophic level derived from the analysis of nitrogen stable isotopes.
- 3Our analyses showed that there has been a significant decline in the mean trophic level of survey catches from 1982 to 2000 and a decline in the trophic level of landings from 1946 to 1998.
- 4The decline in mean trophic level through time resulted from a reduction in the abundance of large piscivorous fishes and an increase in smaller pelagic species which feed at a lower trophic level.
- 5Similar patterns of decline in the trophic level of both catches and landings imply that there have been substantial changes in the underlying structure of the Celtic Sea fish community and not simply a change in fishery preferences.
- 6We suggest that the reported changes in trophic structure result from reductions in the spawning stock biomass of traditional target species associated with intensive fishing, together with long-term climate variability.
- 7The relative distribution of fish market prices has changed significantly over the past 22 years, with high trophic level species experiencing greater price rises than lower trophic level species.
- 8Although decreased abundance of high trophic level species will ultimately have negative economic consequences, the reduction in mean trophic level of the fish community as a whole may allow the system to sustain higher fishery yields.
- 9Management objectives in this fishery will depend on the relative values that society attaches to economic profit and protein production.