Sea Slugs From Outer Space

Janice_Kaspersen_Blog

You might never look at gummy bears in the same way again. This summer, fishing crews all along the West Coast of the US and Canada are finding an abundance of pyrosomes—colonies of jelly-like sea creatures, or zooids—that have been compared, in texture and appearance, to the dense, transparent candy. Typically found only in tropical waters, they were spotted near California five years ago and have been spreading; they’re now common as far north as Alaska.

Pyrosomes – colonies of thousands of individual organisms called zooids – are pictured aboard a National Oceanic and Atmospheric Administration research vessel in the Pacific Ocean off the coast of Oregon in this May 2017 handout photo obtained by Reuters June 26, 2017. Hilarie Sorensen/NOAA Fisheries/Handout via REUTERS

Scientists believe warmer ocean temperatures are leading to the creatures’ spread. Although each zooid is usually no more than a couple of inches long, some grow to as large as 2 feet, and if that’s not disturbing enough, they’re also bioluminescent. So far, the most troubling result is that they become entangled in fishing nets. However, because they eat phytoplankton, some biologists are concerned that they might start depleting the food supply for krill, which in turn is the food source for many fish, whales, and seabirds. “We just don’t know what the long-term implications are,” says a NOAA scientist.

Stormwater runoff from impervious surfaces has sometimes been blamed for increasing the temperature, and thus altering the habitats, of lakes and rivers. But although stormwater does have some important implications for what happens in the oceans, this one’s not on us. This 2016 report from the International Union for Conservation of Nature and Natural Resources examines in detail the causes and implications—some far more serious than pyrosomes—of ocean warming, which the authors say “may well turn out to be the greatest hidden challenge of our generation.”SW_bug_web

Comments
  • Hal Lunsford.

    The warming oceans are like knocking a few brick out of the wall of brick in your home each day. It may not fall today, but the ecosystem is like that wall, which will fall down one day along with the ocean’s abundant seafood that we depend on to survive.

    Reply

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