In 2010, however, MBARI marine biologists re-analyzed the hundreds of hours of video footage from Vrijenhoek's ROV dives. Using the VARS database, the researchers counted all of the different types of animals observed at the Monterey Bay whale falls over the last six years. They discovered that, rather than being whale-fall specialists, most of the animals were "background species," which were common elsewhere in Monterey Bay.
The results of this new research are described in a recent paper published in Deep-Sea Research. The paper was written by MBARI biologist Lonny Lundsten in collaboration with Vrijenhoek and six other researchers.
The research team also studied how the animals at each whale fall changed over time. Like previous researchers, they found that, during the first few months after the carcass reached the seafloor, a few species of scavenging animals, including sharks, hagfish, rattails, and crabs, removed flesh from the whale bones.
As the flesh disappeared, a more diverse collection of animals appeared, including some that fed on whale bones or on seafloor bacteria, as well as predators that hunted animals attracted to the carcass. Overall, however, the Monterey whale-fall communities did not seem to progress through a well-defined or consistent series of stages, as had been observed at other sites.
In fact, each of the whale falls followed a different sequence of community development, involving different key species. There were, however, similarities between the animal communities observed at similar depths. For example, the whale falls in shallower water were sometimes surrounded dense swarms of tiny, shrimp-like amphipods. In the same way, whales at similar depths were colonized by similar species of Osedax worms.
The presence of over a dozen species of Osedax worms reflects the fact that of these
|Contact: Kim Fulton-Bennett|
Monterey Bay Aquarium Research Institute