Seasonal, annual, and long-term trends in commercial fisheries for aggregating reef fishes in the Gulf of California, Mexico

Abstract

In order to assess the contribution of fish spawning aggregations and aggregating species to commercial marine fisheries in the Gulf of California, we: (1) investigated associations between the timing of spawning aggregations and monthly trends in commercial landings and ex-vessel revenues for aggregating reef fishes in the southwest Gulf of California and (2) compared present (2000–2005) and past (1956–1961) landings of aggregating species groups from the entire Gulf. Species known to form seasonal spawning aggregations comprised the eight most important commercial reef fish fisheries of the southwest Gulf with respect to landings and ex-vessel revenues, and three of these species increased in annual landings between 1999 and 2007. Peaks in mean monthly landings and revenues for five of eight aggregating species coincided with the timing of their spawning aggregations, whereas commercial fisheries for the remaining three species did not specifically target spawning aggregation periods. Comparisons of past and present landings showed an expansion of targeted species groups, increased landings for most aggregating species groups, and declines in the landings of several large-bodied species groups. Our results suggest that targeted management of spawning aggregations is needed for some but not all species, assessments on the interaction between fisheries and spawning aggregations are needed for most species, and restrictions on certain gear types are necessary to create sustainable fisheries for aggregating fishes in the Gulf.