Well, some of us would be eating those chocolates instead of passing them around, and instead of accumulating, they will just pass into our group here and not accumulate in any one group because they're absorbed by us.

And they go in the base of that pyramid, and they drift up they're passed up that way, on to predators and on to the top predators, and in so doing, they accumulate.

The dolphins eat the fish that have PCBs from the plankton, and those PCBs, being fat soluble, accumulate in these dolphins.