I have been fishing in battery point and around that area, in the Derwent  Estuary River, I see signboard saying that you can't eat the scale fish and shellfish as the water is heavy metal contamination. Does that mean we can't eat the fish? But again on the right, it shows the fish you can take in homes and in bags.

I have attached an image of that signboard that I talk about. Just zoom in see the written content. Please, guys, any suggestion will be much appreciated.