Sunken Logs Create New Worlds for Seafloor Animals
When it comes to food, most of the deep sea is a desert. Even bits of dead wood, waterlogged enough to sink, can support thriving communities of specialized animals. A new paper shows that wood-boring clams serve as "ecosystem engineers," making the organic matter in the wood available to other animals that colonize wood falls in the deep waters of Monterey Canyon, located in California's Monterey Bay.
In 2006, marine biologists Craig McClain and Jim Barry used the remotely operated vehicle Tiburon to place 36 bundles of acacia wood on the canyon floor, 3,200 m below the sea surface. Five years later, they retrieved the bundles and McClain painstakingly picked out every animal that had colonized the logs.
McClain performed a variety of statistical analyses on the different types of animals found in each of the bundles, looking for differences and similarities. The results were surprising. Even though all of the bundles contained exactly the same type of wood and were placed on the seafloor at the same time, within a few tens of meters of each other, there were huge differences in the numbers and types of animals from one bundle to another. …