Where it comes to our oceans, this is another of those balance things that humans need to be aware of at the least. In Oregon, oceanic biologists test for this and put out results online or you can call. I was taught as a child-- don't eat shellfish with months not having an R in their name. It's not quite that simple now but it is simple to go online and check if they have tested and they're still safe for humans to eat.
On the other hand as the oceans warm, which is what this is about, when will it be safe or will 'red tides' be more than during warm summer days?