Año 1987, Número 7- 21-42

Año 1987, Número 7- 21-42

Cousseau, M.B.; Angelescu, V.A.; Perrotta, R.G. 1987.  Algunas características de la estructura y del comportamiento migratorio de los cardúmenes de caballa (Scomber japonicus marplatensis) en la plataforma bonaerense (Mar Argentino); período 1965-1984.
Rev. Invest. Desarr. Pesq.. 7: 21-42.
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Three periods were distinguished during the analysed years: the first one (1965-1975) may be defined as “normal fishing seasons” occurring from October to March, with catches between 8,000 and 14,000 tons. The second period (1975-1981) was characterized by a decrease in landings of more than 90 % and shorter fishing season (December to January). The third period (1981-1984) has shown a gradual increase in the catches but the presence of the schools into the fishing area was still brief and irregular. Two hypotheses have been proposed in order to account for this behaviour. One of them assumes that the fishing effort applied during more than 50 years on spawning schools has affected the reproductive potential of the species. According to the second hypothesis, the effect of the changes in environmental conditions on the mackerel school movements, would have been the cause of a shift on the spawning grounds outside the fishing area.