RESUMEN
The current work documented a significant and widespread increase in the abundance of the Sydney rock oyster Saccostrea glomerata, in Sydney estuary (Australia) by undertaking surveys of oyster density in the estuary in 1989 and annually from 1994 to 2006. Oyster density at six control sites located in nearby National Parks unaffected by boating and stormwater discharges were compared to 17 study sites widely distributed within Sydney estuary. No oyster populations were evident in Sydney estuary in 1989; however, by 1994 oysters had colonised areas of the lower and central estuary and by 2002 densities were statistically similar to control sites. The timing of estuary-wide increases in oyster abundance suggests that the partial banning of tributyltin in 1989 for vessels under 25 m long may have played a major role in the increase of S. glomerata in this estuary.
Asunto(s)
Estuarios , Ostreidae/crecimiento & desarrollo , Animales , Australia , Conservación de los Recursos Naturales , Monitoreo del Ambiente , Nueva Gales del Sur , Densidad de Población , Contaminación del Agua/legislación & jurisprudencia , Contaminación del Agua/prevención & controlRESUMEN
Two years after the banning in New South Wales (Australia) of tributyltin (TBT)-based antifouling paints for vessels under 25 metres in length, the impact on the Sydney rock oyster, Saccostrea commercialis, has been assessed. Reduced growth and shell deformities present before banning were found to be absent and healthy oysters contained TBT at concentrations close to the detection limit of 0.2 micrograms Sn kg-1. High tissue concentrations of both copper and zinc, prior to banning were also significantly reduced. This behaviour was predicted by field experiments which showed that TBT had a synergistic effect on the uptake of copper. The distribution of both TBT and copper in the various organs of the oyster were examined in an attempt to explain this synergism.