If a bio-accumulation were to get into the ocean, it would destroy the environment. It would probably not quite kill the plants, but it would kill hundreds of thousands of fish. And that would cause the birds, dolphins, and large whales occur bio-magnification. If bio-magnification happened then more and more chemicals would enter that animal. If that happens than the tertiary/apex animals would eat each other, that would cause a huge blood bath and I don’t know what would happen. But if the sharks, and killer whales killed each other than the decomposer would only decompose what was left of the animals/biomass and it would wildly grow over the whole ocean, and would suffocate other plants. But if any toxic waste got into any biome, it would cause the same type of reaction as the underwater biome.