Benthic ecosystem modelo f the Sinaloa continental shelf, Mexico

Abstract

The trophic network of the southern Sinaloa benthonic ecosystem was reconstructed for the period 1994–1997, using Ecopath with Ecosim version 5.1. The ecosystem is a resource for finfish and shrimp fisheries. The majority of the 37 functional groups were determined from the makeup of captures taken by commercial trawls similar to those used by the shrimp fishery. Incidental captures represented approximately 91% of the total and consisted mainly of fish from the families Sciaenidae, Haemulidae, and Serranidae, followed by macrocrustaceans (Portunidae) and invertebrates (Echinodermata). The trophic model obtained had a pedigree index of 0.57, which represents an acceptable quality from the data used. The ecosystem is represented by 4 discreet trophic levels; medium-level carnivores, including Pleuronectiformes, birds, Sciaenidae, Serranidae, and Centropomidae, contribute the majority of energy transfer in the third level. The mixed trophic impacts show that detritus positively affects the majority of functional groups, mainly the primary consumers (TL=2). The shrimp fleet also uses the Penaeidae as a resource. Primary producers exert a positive impact on groups taken by the finfish fleet, although to a lesser extent. The ecosystem is in a low state of maturity or development according to system attributes, which indicate an overhead of 2.3 times the ascendance.