In brief: Michel André and colleagues discovered that loud sounds can severely damage the statocysts (sort of like our inner ears) of several different species of cephalopods, including two squids. The sounds they used in their experiments are comparable in frequency and strength to the noise pollution that humans are constantly pumping into the ocean with shipping, drilling, etc., and the scientists say their results "indicate a need for further environmental regulation of human activities."
By now, I think a lot of people are familiar with the idea that loud noises can bother whales and dolphins--but squid? Until quite recently, we weren't even sure squid could hear. And it's still anyone's guess whether the sounds emitted by hunting whales have any effect on their squid prey.
So a study that shows conclusive evidence for loud noises damaging squid is pretty exciting. The story was picked up by the popular science sections of Nature, Science, Discovery, and many other outlets.
Everyone has a different angle on the story, which makes for fun reading. However, the first article I read was Discovery, and it horrified me. Here's the opening paragraph:
Thousands of Humboldt squid died off the coast of Oregon in 2004 and hundreds again in 2008. The culprit was originally considered a shift in deep-sea currents, but a new study pinpoints the physical trauma noise pollution can inflict on cephalopods and raises new concerns over the incidents of squid strandings.Given my passion for dispelling the endless myths about Humboldt squid, you can imagine my knee-jerk reaction . . .
Humboldt squid strandings haven't been restricted to Oregon! There was a big stranding in La Jolla in 2002! And no one knows why any of them happened, though explanations have ranged from the plausible (temperature changes) to the ridiculous (earthquakes). I've never heard anyone propose "a shift in deep-sea currents."
The implied link between Humboldt squid strandings and noise pollution is simply disingenuous. We don't have any statocysts from stranded Humboldts to examine, so there's absolutely no evidence one way or another.
The ScienceNOW hook was much more accurate and informative. They talked about strandings of giant squid (not Humboldt squid) in Spain that had been legitimately linked to noise:
At the time of the strandings, ships offshore were exploring for oil and gas with air guns, which produce high-intensity, low-frequency sounds. Some researchers suspected that the loud noises were harming the squid, just as they are known to harm marine mammals.The ScienceNOW article is my favorite, in fact. It was this article that reminded me whales aren't the only animals people have already studied for effects of noise pollution:
In recent years, scientists have gathered evidence that sonar and other humanmade noises may hurt everything from whales to crustaceans.Crustaceans--crabs and lobsters and shrimp--have long been known to make noise by snapping and tapping their hard exoskeleton. (If you don't like your friends to crack their knuckles, snapping shrimp would probably drive you nuts.) And research has shown, not too surprisingly, that crustaceans respond to noise as well as generating it.
That's a bit of a contradiction with the squid press release, which quotes André as saying:
This is the first study indicating a severe impact on invertebrates, an extended group of marine species that are not known to rely on sound for living.Whoops, guess he forgot that crustaceans are invertebrates too!