From Primary Predator to Picked-on Prey: Shark Fishery in the Pacific Ocean

by Hannah Tannenbaum

In 2001 sharks were first listed as endangered species, and since then several measures have been enacted towards their protection. However, the majority of shark fishing is an incidental byproduct of purse seine and long-line fisheries which operate outside of national Exclusive Economic Zones (EEZ). Therefore the effectiveness of international treaties banning shark finning is hard to discern. Another major difficulty in assessing the effectiveness of conservation is the paucity of data on shark population size and structure. Clarke et al. (2013) collected and analyzed onboard observer data on shark catches from 1995–2010 in order to evaluate the threat to sharks from commercial fishing, and determine changes in shark populations after finning bans were established. The authors analyzed data on blue, oceanic whitetip, silky, and mako sharks because of their tendency to appear as bycatch in the Pacific tuna fishing industry. Through the analysis of observer data, no clear trend of reduced catches was found consistently for any species, any area, for either type of fishery. The authors suggest that shark retention bans may have a greater impact on population size than finning bans, and that management and monitoring must be made more consistent in order to properly evaluate conservation. Continue reading