Here's a scary thing, marginal to this discussion: On a Nova show last year,
they said that some killer whales' body tissue contains so much toxic crap
(by parts per million or however it's measures) that if the animals were
land-based waste, they'd be subject to special handling by whoever needed to
discard them. I'm sure the fish we eat don't have the same issues, though,
because they swim in special water, unlike the whales.