The simple answer is that it falls from above. Most life in the deep sea environment relies on various pieces of food falling from the sunlit surface waters. This falling food can take many forms, much of it falls as marine snow, tiny dead and rotting animals, fish scales, and poop. At the end of their lives, larger creatures also fall to the seafloor, such as sharks, squid and whales. In a barren food desert, whale carcasses can become islands of feasting.