Visualizing the Food-Web Effects of Fishing for Tunas in the Pacific Ocean

摘要: We use food-web models to develop visualizations compare and evaluate the interactions of tuna fisheries with their supporting food webs in eastern tropical Pacific (ETP) central north (CNP) Oceans. In ETP CNP models, individual slightly different that are defined by assemblage targeted species. Distinct energy pathways required support species and, consequently, specific target assemblages. These simulations suggest catches tunas, sharks, billfishes have lowered biomass upper trophic levels both systems, whereas increases intermediate lower level animals accompanied decline top predators. Trade- offs between fishing predation mortality rates occur when multiple interact respective may lead smaller changes than if only effect a single fishery is considered. Historical hypothetical management scenarios further demonstrate effects longline purse seine been strongest levels, but respond more strongly purse-seine fisheries. The apex predator guild has responded most longlining. Simulations alternative strategies attempt rebuild shark billfish populations each ecosystem reveal (1) longlining effectively recover do seining (2) restrictions on shallow-set gear finning predators simple reductions effort.