ISSN:
1432-1793
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Mussels, Mytilus edulis L., were subjected to high temperatures, low salinities and dissolved zinc in order to investigate possible environmental hazards of a discharge of heated effluent near Newport on the Yarra River estuary, Victoria, Australia. Exposure to zinc at 0.8 mg l-1 for 14 d in otherwise favourable conditions significantly increased mortality resulting from subsequent exposure to temperatures between 29° to 31°C for 24 h without added zinc. Mussels collected from water of temporarily lowered salinity (8‰–16‰ S) showed significantly lower thermal resistance than controls collected from marine salinities (35‰ S). Mussels taken from a marine environment and exposed to 10‰ S died at a rate which increased with temperature. Mussels acclimated for 14 d to combinations of 10°, 16° and 22°C and 22‰ and 35‰ S, and subsequently exposed to increased zinc concentrations accumulated zinc to levels which were independent of temperature and salinity. The zinc was lethal more quickly at 22°C and 35‰ S than at the lower temperatures and salinities. The modes of toxic action of the salinity, zinc and temperature factors are discussed and it is argued that zinc which has been found accumulated in mussels near Newport could be reducing their resistance to raised temperatures and perhaps other stresses, probably as a result of effects on lysosomal functioning. The evidence suggests that the heated effluent will accelerate any toxic effects of zinc or low salinities which occur near Newport and so poses a hazard in winter as well as in summer.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00397600
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