Publication Abstract

Impacts of fishing on diversity: from pattern to process

Impacts of fishing on diversity: from pattern to process

S. Jennings and J.D. Reynolds

1. Fishing has led to reductions in the diversity of fish and invertebrate communities in the north-east Atlantic.

2. Diversity can be measured in many ways. Some approaches emphasise species richness, while others emphasise the distribution of individuals among species and the evolutionary relatedness among species.

3. Reductions in fish diversity result from the direct mortality of target species rather than the indirect effects of fishing on trophic relationships.

4, Reductions in invertebrate diversity result from the effects of towed gears on the seabed. This effect is particularly apparent on stable substrates, but may not be detectable where mobile sediments are continually resuspended by waves and tides.

5. It is difficult to separate biogeographical patterns in diversity from patterns induced by fishing. Large-scale studies of fishing effects on invertebrate diversity can only proceed if the spatial resolution of fishing effort data is reduced to metres rather than tens of kilometres.

6. Links between fish or invertebrate diversity and the stability or productivity of marine communities are not known. We should aim to start describing both pattern and processes in order that we can describe the effects of fishing on ecosystem function.

7. Considerable resources are required for diversity studies and diversity is not a particularly sensitive measure of fishing effects. An alternative is to use multivariate methods to identify indicator species that are vulnerable to fishing. Studies of the abundance and distribution of these species would provide a cost-effective approach for identifying areas impacted by fishing.

Reference:

S. Jennings and J.D. Reynolds, 2000. Impacts of fishing on diversity: from pattern to process. pp235-250, In: Effects of fishing on non-target species and habitats: biological conservation and socio-economic issues (ed. M. J. Kaiser and S. J. de Groot). Oxford: Blackwell Science.

S. Jennings* and J.D. Reynolds

pp235-250, In: Effects of fishing on non-target species and habitats: biological conservation and socio-economic issues (ed. M. J. Kaiser and S. J. de Groot). Oxford: Blackwell Science