The yellow clam (Mesodesma mactroides): a case study of a coastal resource in risk from the South Western Atlantic Ocean

BASTIDA, R. O.; IENO, E.; MARTIN, J. P.; MABRAGAÑA, E

Journal of Medical and applied Malacology

Año: 2000 vol. 8

The aim of this study is the report the general situation of the yellow clam (Mesodesma mactroides) along the coast of Buenos Aires Province (Argentina) during the summer of 1995 and 1996, as well as the occurrence of a massive mortality of the species in Oct/Nov 1995. In order to assess the status of the population, we applied the methods followed by Olivier & Penchaszadeh, 1971 and Bastida et al., 1991. The results obtained in the first stages of this work denoted an inproverishment of this commercial and touristic resource, worse than that reported by Bastida et al. in 1989. During October and November 1995 an unexpected mortality occurred which has not been reported in Argentina before. This phenomenon also extended to Brazilian and Uruguayan beaches Sampling programs carried out after this event revealed that all size classes were affected. However, a few srecruits appeared in different beaches. Mortality causes remain still unknown both in Argentina and in the other countries. Anyway causes due to phytoplankton toxins, chemical contaminants and parasitism, were rejected. However, specific viral disease could be associated with observed mortality. Every precaution must be taken to reduce the risk of this benthic resource, thus harvest in these areas should be forbidden. This makes necessary a regional agreement to continue the study of this species. We recommend, in the immediate future, extensive clam aquaculture in order to increase population stocks.