Linking Ecology, Economics, and Fleet Dynamics to Evaluate Alternative Management Strategies for US West Coast Trawl Fisheries

This work bridges this symposium’s morning session (Modeling of Human Behavior and Fish Populations) and the afternoon session (Ecosystem Models to Address Fishery Management Needs). We present a model intended to provide U.S. West Coast fisheries managers with a tool to test the efficiency and robustness of alternative fishery management strategies in an ecosystem framework. In January 2011, the Pacific Fisheries Management Council implemented an individual quota (catch share) system for the West Coast groundfish trawl fleet. Under the individual quota system, each vessel now has dedicated access to a portion of the quota for groundfish, such as rockfish and flatfish. The modeling work presented here investigates the ecological and economic effects of this new management regime. We use an integrated ecosystem model of the US West Coast (Atlantis) to simulate the abundance of target fish species and other biological groups. We simulate fleet dynamics for the 12 major groundfish fleets, with each fleet choosing fishing locations that maximize net revenue. Net revenue includes landed value of the catch, minus the cost of quota and fixed and variable costs. We explicitly include the penalty that fishers expect if they exceed their quota. The main findings are: 1) Even with crude spatial resolution, under the individual quota scenario the simulated fleets show some improved targeting behavior, avoiding overfished rockfish species and aiding recovery of these stocks.  2) The penalty fishermen expect for exceeding quota has a large effect on fleet behavior, pointing to the importance of monitoring and enforcement. In addition to providing insights into how alternative fishery management policies will affect the profitability and sustainability of fisheries, the model illustrates the wider ecosystem impacts of fishery management policies.