NEWS FLASH! (kind of)
Researchers in Sweden have just discovered a number of new species of something called a "bristleworm" - a creature that feeds at a rare but rich banquet table at the bottom of the ocean: Whales carcasses. These islands of nutrients are called "whale falls" in the marine bio biz.
When such a carcass does sink onto a particular part of the sea floor it represents the equivalent of 2000 years of nutrients that the same surface area would otherwise receive drifting to the bottom from the upper ocean.
( "When it rains it pours" - even in the ocean!)
These Whale Falls support diverse communities of organisms. Some wander by and take easy and opportunistic advantage, such as sharks or generalist scavenger fish. Others, however, live (quite literally) for this very unique culinary event.
Some specialize of the blubbler or flesh. Others, like the bristleworms discovered in this research feed of the specific bacteria that feeds of the whale flesh! Talk about an ecological niche.
As we see, trophic webs can develop from ot only autotrophic primary producers like plants! Decomposition and the predatation, parasitism, etc that follow also generate complex food ecologies.....