Laboratory photo of one of the newly discovered
bone-eating worms, Osedax frankpressi, which has been
removed from a whale bone On the heels of two humpbacks leaving the Sacramento River for the ocean, you may have seen this other news report on a rotting gray whale carcass on waterfront property at Point Richmond. (There's a historical irony here too, because Point Richmond was also the site of the last whaling station in the US). As Bay Area residents know all too well, whales are frequent visitors to the SF Bay, and often times they do strand themselves, die or simply get carried into the Bay by prevailing ocean currents.
Dead whale carcasses can be an awful mess (literally, logistically, and administratively), but 30 years ago, a group of scientists in a deep-sea submersible discovered something amazing in the Santa Catalina Basin: dead whale carcasses that sink to the bottom of the ocean floor can support a unique deep-sea community of invertebrates and scavenging vertebrates in an environment completely divorced from the light of the sun. What's amazing is that some of these whale-fall invertebrates have evolved a means of harnessing the lipid-rich resources of the whale carcass via chemosythentic bacteria that live symbiotically -- that is, right within their own bodies. Some species of molluscs that do this are the same ones that have been found at deep-sea hot vents; others, like Osedax, seem to be restricted to whale-falls.
Because whale-falls are oases of nutrients in an otherwise low-nutrient environment (the ocean floor), scientists have proposed that whale-falls have provided "stepping-stones" for deep-sea invertebrates to disperse across ocean basins, and to over nutrient-rich environments like hot vents and cold seeps. If whale carcasses are crucial to the deep-sea organisms, we might expect that a century's worth of whaling -- and the removal of whale carcasses from the oceans -- had serious effects on these deep-sea communities. Unfortunately, as with many enigmas of marine ecosystems, we still don't enough about the oceans right in our backyard to know the answers to these riddles.
Nick Pyenson is a PhD candidate at the University of California, Berkeley, in the department of integrative biology and the museum of paleontology.