El Barril fisherman transports two Carcharinids for processing (Photo: Joseph Bizzarro)
Shark and ray resources worldwide are today experiencing their highest rate of reduction due to fishing activities than any other time in history. The future of this trend is uncertain. Elasmobranch fishes have life history characteristics that make them particularly vulnerable to overfishing (Holden 1974). These characteristics include slow growth, delayed ages at maturity, low fecundity, and long gestation periods, as well as low absolute numbers in apex predator species. Because of these limitations, fishing of sharks and rays can lead to depletion of stocks, negatively influencing these resources and their ecological value over broad regions. In the U.S., these limitations have led to recent problems and a resulting need for management of elasmobranch fisheries on both Atlantic and Pacific coasts (Cailliet and Bedford 1983, Cailliet et al. 1983, NMFS 1993).
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Mexican elasmobranch fisheries have expanded to become the largest in the Americas (Bonfil 1994). Since 1981, the Mexican shark fishery has yielded almost 30,000 t per year (Castillo et al. 1996). Most of the yield is from the Pacific Coast where a primarily artisanal fishery targets large sharks ("tiburones"), small sharks ("cazones"), which include juveniles of larger species, and rays (Castillo 1992, Villavicencio 1996). The Gulf of California (Sea of Cortez) region is thought to serve as a crucial nursery habitat for a diverse assemblage of sharks and rays. However, the fisheries there are largely unregulated and catch records are scarce. Information regarding the basic biology of most targeted species is limited at best. These combined factors create conditions under which the depletion or collapse of the Gulf of California’s targeted elasmobranch populations is possible. | 
Racks of salted shark flesh drying in the sun at El Barril, Baja California Norte, Mexico. The primary catch during the summer of 1998 survey consisted of dusky sharks, Carcharhinus falciformis, and adult hammerheads, Sphyrna sp.. (Photo: Wade Smith) |
To improve the understanding, conservation, and management of shark and ray fishery resources in the Gulf of California, a two-year multi-institutional collaborative project involving researchers and fishery resource professionals from Mexico and U.S. has been initiated. The overall objectives are to:
1) determine the locations and activities of the main shark and ray
fishing camps in the Gulf of California
2) determine catch composition of sharks and rays from the various shark
and ray fishing camps in the Gulf of California. In addition to species
composition, abundance, catch locations, sizes, weights, and sexes of specimens,
specimens are being collected for studies on reproduction, age and growth,
and feeding habits to obtain critical life history information and
3) design and implement a shark-tagging program to determine the extent
and characteristics of shark nursery areas and the degree of exchange of
shark into and out of the Gulf.
The information resulting from the assessment of elasmobranch fisheries within the Gulf of California will be used to formulate management strategies for the conservation of sharks and rays which will be incorporated into a regional management plan currently under development by the Mexican fisheries agency, Instituto Nacional de la Pesca.
Local fishermen targeting batoids dress their catch on the beach
at Las Animas, Baja California Norte, Mexico (Photo: Joseph Bizzarro)
Created by: Erica Burton
Comments:webmaster@mlml.calstate.edu
Last Revision: 28 January 2004