Lenfest Ocean Program

Supporting Science and Communicating Results

Published Paper

Ecosystem Effects of Invertebrate Fisheries

Eddy, T. D., Lotze, H. K., Fulton, E. A., Coll, M., Ainsworth, C. H., de Araújo, J. N., Bulman, C. M., Bundy, A., Christensen, V., Field, J. C., Gribble, N. A., Hasan, M., Mackinson, S. and Townsend, H. (2016), Ecosystem effects of invertebrate fisheries. Fish and Fisheries. doi: 10.1111/faf.12165

Key Findings:

  • Since the 1950s, the catch of invertebrate fisheries in the world’s oceans has increased six-fold, to over 10 million tons annually, due largely to declines or more restrictive management of finfish fisheries. In the water, invertebrates are a critical food source for finfish, mammals, and birds. Yet many invertebrate fisheries lack stock assessments and management plans—key tools for understanding a fishery and ensuring its sustainability.
  • To study the consequences of invertebrate fisheries, researchers used 12 ecosystem models based on real data from around the globe. They analyzed 73 invertebrate groups and simulated fishing intensity ranging from none to local extinction. Effects were measured on other groups in the ecosystem, including species of commercial or conservation interest.
  • They found that fisheries for cephalopods (squid, octopus, and cuttlefish) and lobsters had the strongest ecosystem effects. These were comparable in magnitude to the effects of fisheries on forage fish—small, schooling species that are critical prey in many ecosystems.  
  • The researchers also found that invertebrates are generally more sensitive to fishing than finfish. On average, invertebrates produce maximum sustainable yield (MSY) when their abundance is at 65 percent of its unfished maximum, compared to 45 percent for finfish.
  • The models highlight a potential win-win scenario: Reducing fishing pressure to maintain invertebrate biomass at 75 percent of unfished biomass could greatly reduce ecosystem impacts while still producing 90 percent of maximum catch.
  • Unlike forage fish, many invertebrates do not follow the traditional fisheries science prediction that only highly connected or highly abundant species will have high ecosystem impacts. This demonstrates the need to manage ecosystems as a whole rather than separately by their parts, since the consequences of fishing and other human activities can be unpredictable.

The full publication is available here:

http://onlinelibrary.wiley.com/doi/10.1111/faf.12165/abstract.

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Elizabeth Striano

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