In the Great Bear Rainforest in British Columbia, the trees get 80% of their nitrogen from salmon leftovers discarded by bears..
My mum's cat used to leave goldfish carcasses in the vegetable garden. Probably had much the same effect..
and there are maggots that eat those carcasses, and parasitoids on those maggots, and hyper-parasitoids on those parasitoids... The hyper-parasitoids are at a higher trophic level than Orca...
But they're food for predatory heteroptera which are bird food so the birds in this rather smelly forest are accumulating neonicotinoids like nobody's business..
The circle of life.