Sharks and food webs

Tiger sharks and other large sharks are top predators that help maintain the health of marine ecosystems. But sharks populations are in trouble globally. The decline of the shark population produces unexpected and devastating consequences for the food web.

Research initiated by the PEW Shark Campaign has shown correlations between the balance of shark population and the fish stock of commercially important fish species such as tunas and jacks. The impact of those researches is of special importance for understanding how actions should be taken to protect the shark species and the health of the oceans.

Production Credits:

  • Advisor: Villy Christensen

  • Production: Jeroen Steenbeek

  • Visualization: Dalai Felinto and Mike Pan

  • Funding: The Pew Environment Group

Based on the following studies:

Stevens, J.D., R. Bonfil, N.K. Dulvy and P.A. Walker. 2000. The effects of fishing on sharks, rays, and chimaeras (chondrichthyans) and the implications for marine ecosystems. ICES Journal of Marine Science 57:476-494., J.J. 1984. Model of a coral reef ecosystem: The ECOPATH model and its application to French Frigate Shoals. Coral Reefs 3:1-11., A.M. and E.E. DeMartini. 2002. Contrasts in density, size, and biomass of reef fishes between the northwestern and the main Hawaiian Islands: the effects of fishing down apex predators. Marine Ecology Progress Series 230:253-264.