Ichthyofauna catch composition in a small-scale fishery from Isabel Island (Southeastern Gulf of California), Mexico

Isabel Island is a National Park located in Northern Mexico with an unprotected marine area that allows small-scale fishing. The impact of this activity on the ecosystem and exploited biological resources has not been evaluated in this area. From May 2013 to April 2014, the fishing camps on Isabel Island were monitored monthly. The most widely used fishing gear was the gillnet (96.4 %), hook-and-line (2.1 %) and long-line (1.5 %), all of which caught 2 388 organisms, corresponding to 19 families, 33 genera, and 46 species. The most frequently captured were Lutjanus peru (%IRI= 55.34), L. guttatus (%IRI= 16.01), L. argentiventris (%IRI= 11.53), Cynoscion reticulatus (%IRI= 3.23) and Hoplopagrus guentherii (%IRI= 3.02), representing 89.13 % of the total catch. The diversity was low (H'= 2.01) and dominated by few species (J' = 0.52), mainly snappers (Lutjanidae).