system
Given the following post, respond as if you're commenting on Reddit:
human
If fish accumulate mercury in the more toxic, methylmercury form, is it toxic to them?

Mercury is toxic to humans. Is it toxic to fish? If so, are fish affected at all by all the mercury they absorbed in their body?
gpt
It is toxic to everything as far as I’m aware. The major danger of the bio accumulation idea is that the higher up in the food chain an organism is the more it will accumulate those toxins and die. So for example a plankton might have only a few molecules of mercury in it, but then zooplankton eats 20 of those so it has 20x the mercury in it. Then a fish eats 20 of those and so it has 400x the mercury in a plankton. And so if a human eats fish five times a week that human is potentially eating lots of mercury, and that mercury isn’t ever excreted by the body.