By-catch of sharks in Patagonian coastal trawl fisheries

In coastal Patagonia, Argentina, an unknown number of species of sharks are frequently caught in bottom-trawl nets. Between 1993 and 1996, 454 trawls by Patagonian coastal fisheries (41 degrees-51 degrees S) were analysed; 26 4 included sharks. Of the seven species of sharks caught, the most frequent was the smoothhound Mustelus schmitti, mainly in Bahia Engafio (off Chubut ). The argentine angelshark (Squatina argentina) and the tope (Galeorhinus galeus) were common in the north of Patagonia, the piked dogfish (Squalus a canthias) in the central zone, and the narrowmouthed catshark Schroedericht hys bivius in the south. The broadnose sevengill shark (Notorhynchus cepedi anus) was rarely caught. A single basking shark (Cetorhinus maximus) was ca ught in San Matias Gulf(off Rio Negro). Although undesirable, the by-catch of sharks is growing as a result of the increase in the fishing activities of the region, and the sustainability of the shark populations in Patagonia n coasts is a matter of concern.