Incidental mortality of patagonian dusky dolphins in mid-water trawling: retrospective effects from the early 80´s

DANS, SILVANA LAURA; ALBERTO CRESPO, ENRIQUE; ANÍBAL GARCÍA, NÉSTOR; MARINA REYES, LAURA; NOEMÍ PEDRAZA, SUSANA; KOEN ALONSO, MARIANO

Report Of The International Whaling Commission

International Whaling Commission

Lugar: Cambridge, UK; Año: 1997 vol. 47 p. 699 - 704

The highest rates of incidental catches of dusky dolphins off Patagonian coast mostly occur in mid-water trawling for shrimp. At present, this fishery is declining in use, but it was widely used during the 1980s. The objectives of this paper are to estimate the number of dusky dolphins annualy caught in this fishery during the period 1982-1995 and to analyse the structure of the catches and possible effects on the population. The use of this gear for shrimp began in 1982. During 1984, the fishing effort reached a peak and the number of dolphins caught was estimated at between 442-560, decreasing during the following years. The use of mid-water nets for shrimp was recorded up to 1994, when mortality estimates reached a minimum ovalue equal to 36 dolphins per year.