The main role that Atlantic cod have in the ecosystem is their involvement in the food chain. Atlantic cod feed upon a variety of organisms such as invertebrates, crustaceans, and zooplankton. Larger marine organisms (i.e. sharks, seals) prey upon and consume Atlantic cod. The interplay between predators and prey is the key way in which cod influence their ecosystem. No information concerning specific relationships (mutualism, parasitism, etc.) was available. ("Assessment and Update Report on Gadus Morhua (Atlantic Cod)", 2003; Campbell, 2005)