Most seafloor animals feed on the organic remnants of algae and animals that live in the sunlit surface waters. This takes the form of marine snow – particle that fall to the bottom. One problem is that this doesn’t happen very often.
Scientists have shown that wood that falls into the sea can provide an unexpected nutritional source. Here wood-boring clams function as ecosystem engineers and they make the organic matter in the wood available to other animals. This was discovered by
examining wood falls in the deep waters of Monterey Canyon.
The ecosystem differences were shown by variety of statistical analyses on the different types of animals found in different areas of the sea. Remarkable differences were found in areas where there was dead wood and where clams were present. Essentially, as the wood got older and more heavily colonized by wood-boring clams
), the types and abundances of other animals also changed. As they eat their way through a sunken log, boring clams create lots of small holes in which other animals can hide. Their wood chips and feces provide food for a variety of smaller animals. And the clams themselves provide food for specialized predators.
The study was carried out by biologists at the National Evolutionary Synthesis Center and the Monterey Bay Aquarium Research Institute (MBARI). The findings have been published in
the journal Biology Letters
, in a paper titled “Beta-diversity on deep-sea wood falls reflects gradients in energy availability”.