| Summary: | Bathymetric changes in groundfish catch composition are analyzed, on the basis of routine reports of 106 bottom longline strings. The project was conducted from 12 December 1986 to 29 November 1987, covering areas from coastal waters to the outer shelf of the continental shelf off Argentina from 36° to 55°S. As a preliminary step to the analysis, the validity of each factor as probable explanatory variable in each area, was analyzed with consideration as to their range and variation. Obtained results show that the kingclip (Genypterus blacodes), a main objective of the project, could become one of the most profitable target species of the high-sea bottom longline, in areas along the outer edge of the continental shelf, at bottom depths slightly below 200 m. In this area the "bacalao criollo" (Salilota australis), was one of the most profitable by catch, or subsidiary target species to the kingclip. When lines were settled in the areas and depth zones covered by this and a preceding operation obtained results indicate that the Argentine hake (Merluccius hubbsi)could be neither the target species nor by-catch, due to the extremely poor catches. The Patagonian toothfish (Dissostichus eleginoides)lives in deeper grounds than those covered by most of the strings settled during the present projetc. The Argentine seabass (Acanthistius brasilianus)was considered one of the probable target species for coastal boats using bottom longline operations in inshore waters along the Patagonian coast. Smoothound (Mustelus spp.)were hooked abundantly over wide areas and have the potential of becoming one of the target species or a profitable by-catch. Grenadier fish (Fam.Macrouridae, several spp)were hooked abundantly by those parts of the strings that extendet to deeper grounds. Rosefish blackbelly (Helicolenus dactylopterus), Brazilian sandperch (Pseudopercis semifasciata), hagfish (Myxine spp.)and Argentine conger (Conger orbignyanus)were caught during the present operation, either in limited areas or at a low density, thus ...
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