Throphic Model for the Ecosystem of La Paz Bay, Southern Baja California Península, Mexico.

Abstract

A trophic ecosystem model of La Paz Bay, on the southern Baja California Peninsula, was improved from one previously constructed by adding 13 functional groups. In the bay, small-scale fisheries take place, which are aimed at finfish, shark and clams. Also there is a pilot shrimp trawl fishery. At the mouth of the bay, communicating with the Gulf of California, there is the insular complex of Espíritu Santo, which was declared as a protected area by the federal government. The aim for the construction of a model of La Paz Bay is to help run scenarios of the fleets and MPA operating together to support fisheries management within an ecosystem context. We present a full description of the ecosystem structure and basic functions based on Ecopath software. The Ecosim model is used to calibrate time series of relative abundance of several groups, which served as the basis for spatial modeling. Preliminary simulations suggest a limited effect of the MPA around Espiritu Santo Island on marine birds, sharks and red snapper.