This seaweed is a bit of a worry

[Lilith7]

It may be that, in the future our climate becomes too extreme to grow food outside & it will have to be grown under cover. And perhaps our seas will become too polluted with stuff like this or actual rubbish we've gaily chucked out, & we might need to somehow create small seas inland away from the pollution & perhaps under cover so we can still have fish.

I don't envy our descendants...