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 details of these interactions are still poorly known. For example, after boring clams, the most common animals McCain found in his bundles were tiny, shrimp-like crustaceans known as tanaids. The authors speculate that these tanaids may prey directly on the boring clams. Alternatively, the tanaids may consume the fecal pellets of boring clams and the bacteria associated with them (any organic matter is precious when you're three kilometers below the ocean surface).
The statistical analyses also showed that large logs supported more diverse communities of animals than small logs. The researchers speculated that larger logs may provide food for a longer time period, which attracts more secondary colonizers, such as deep-sea snails. McClain explained, "Snails, contrary to what you might expect, are metabolically expensive. They may need a lot of energy, such as that found a large wood fall, to support a viable population."
One of the most surprising discoveries was that, even after five years, some bundles contained only a few small, young boring clams, and o
|Contact: Kim Fulton-Bennett|
Monterey Bay Aquarium Research Institute