Toxicity of edible mussels (Mytilus edulis) growing naturally in an estuary during a water bloom of the blue‐green alga Nodularia spumigena

Possible accumulation of toxicity by edible mussels growing in a water bloom of Nodularia was investigated during the annual eutrophication of a brackish/marine water estuary in Western Australia. At a cell density of 100,000 cells/mL water, during the growth phase of the bloom, the gut and gut contents of mussels showed the highest toxicity of about 90 mg dry weight of tissue lethal to 1 kg mice by sterile (boiled) i.p. injection. Death was due to hepatotoxicity. It was concluded that edible mussels should not be collected for human consumption during a toxic blue‐green algal bloom.