Alvin during a deep sea mission.
As humans venture out to new corners of the world, so do invasive species. This story is old: mice hid out on Viking boats, plant seeds followed scientists to Antarctica, and, now, limpets have hitched a ride on the deep sea submersible Alvin. This last finding, published in Conservation Biology, surprised scientists, who didn’t think that limpets could survive drastic pressure changes as Alvin surfaced between dives.
Since 1964, Alvin, the little sub that could, has made thousands of scientific dives—from surveying the Titanic to exploring hydrothermal vents. The sub and its sampling gear are cleaned between each dive, but this new limpet discovery suggests a mistake happened somewhere down the line.
Scientists on a dive mission in 2004 collected 38 limpets hundreds of miles from their known range and far from the hydrothermal vents where they usually live. A closer look at the preserved specimens confirmed the scientists’ fears. The morphology, DNA sequence, sex ratios, bacterial colonies, and isotopes of this population exactly matched those of a previous sample taken by Alvin in a different part of the Pacific.
For researchers, disturbing the very ecosystems they’re trying to study is bad for both science and the environment. They don’t want misinformation about where limpets live nor do they want invasive species to spread and disrupt the deep sea ecosystem. There’s talk of upping standards for cleaning equipment and using freshwater to get rid of any lurking marine creatures.
If limpets did indeed hitch a ride on Alvin—the evidence is worrisome but still only circumstantial—it’s impressive that these creatures adapted to bone-crushing pressures of the ocean’s depths survived a trip to the surface. The deep sea still has its mysteries.
[via Nature News]