As if you needed it, there’s another reason to love our local sea otters: they’re fighting destructive crabs.
For decades, scientists have fretted about an invasion of green crabs who actually use theirĀ breathing apparatus (gills) to eat, which sounds super weird. And the crabs aren’t just weird, they’re harmful. To quote from the Smithsonian:
“[The green crab]Ā has no predators or competitors and also a killer appetiteācrab, fish, young lobster, and shellfish are no match for its nimble, yet crushing claws.”
Not Good Actors
In case you feel sorry for these food-inhaling critters, know that they are an invasive species, introduced to the US from Europe in the 1800s, and marine scientists are pretty disappointed with them. Green crabs don’t just eat critters like clams or fish. No, they gobble up whole ecosystems including sea grass, home to countless young of various species. No sea grass, no sea life.
The situation progressed from not great to really bad. Warming waters in the past decades led to an explosion in the green crab population and marine scientists from Maine to Baja California were freaking out.
Why Not Just Eat Them? Or…
Some suggested people start eating these pesky crabs. They’re eaten in Italy, but not usually in the USA: small, hard to catch, described as “bland.”
Of course, the green crabs even eat the tasty Dungeness and Blue Crabs that people prefer. They just can’t do anything right.
But here in Coastal California, we have a secret weapon: sea otters.
The southern sea otters we know and love were almost extinct in the last century, hunted for their luxuriousĀ fur. They only survived because a few dozen animals managed to shelter off the coast ofĀ Big Sur (yay Big Sur!).Ā But conservationists won out and as people stopped slaughtering otters for their furĀ they resurged. From as few as 50, now there are tens of thousands. They’re still “threatened” but no longer “endangered.”
And they’re eating the invasive green crabs by the bucketload.
Otters are big eaters. When you see them off our coast they’re almost always eating. They don’t have the layers of blubber that sea lions or seals have, so they keep warm by feeding their super-high metabolisms with as much as 25 lbs of food per day. That’s a lot of crabs.
A group of otters at Elkhorn Slough was found to be eating between 50,000 and 120,000 green crabs per year!
And Now It’s Looking Better
As the otters resurged, marine scientists noticed the green crab population starting to dwindle. In Elkhorn Slough, the whole ecosystem is starting to recover.
Ecologically, that seems like a good thing. A native species fighting back against a damaging interloper. And though we get the occasional otter surfboard stealerĀ like Otter 841, generally they are fun to watch. And honestly ā though this is subjective ā they’re a lot cuter than the green crabs.
šØ First Friday at CruzioWorks!šØ
