Aquarium officials are flagging a rather alarming development.
As the subject line of the email tells it: "Pelagic Red Crabs Take Over Monterey Bay Aquarium's Great Tide Pool."
But it shouldn't be confused with a hostile invasion.
Or the great hot pink sea slug attack around this time last year.
This crab boom will mean more seafood for the likes of local marine mammals and big fish.
As Aquarium spokesperson Mika Yoshida reports: "Pelagic red crabs have been spotted along local beaches, and in the aquarium’s Great Tide Pool! These crabs are usually associated with El Niño conditions, and provide a tasty treat for lots of local sea life."
Those include the wild sea otter mom who touched off a media circus with #CutePalooza2015 last month when she chose to give birth to her insanely fuzzy otter pup in the same Great Tide Pool the crabs now are overwhelming.
They're also a popular bit of prey for skipjack, yellowfin and albacore tuna, which is why pelagic red crabs are also known as "tuna crabs."
Their role in the food web proves vital because they eat tiny plankton, which is too small for larger animals to eat, and make for a great source of food for them, including birds, whales, turtles, dolphins, fish feed on pelagic red crab.
They belong to the squat lobster family, crustaceans scientists call a cross between lobsters and crabs.
Check out "The coolest photo of the pelagic red crab infestation in Monterey Bay" and more on the recent explosion.
Most traverse the open ocean (hence the "pelagic" name), but the largest and oldest crabs, which get to be about 2, hang out way down on the floor of the continental shelf.
They normally live down by Baja California and points south.
The last time they appeared locally in these numbers was 1983.
As an MBA tumblr blog points out, "Warmer waters building with this winter’s El Niño—coupled with “The Blob” of tepid seas hanging off the coast since last year—could mean these crabs continue their current-driven journey even further north."
Learn more about a historic year in marine activity in 2015 with "A look back at the most remarkable year in Monterey Bay."
The post continues from there: "For local sea life, it’s a feeding frenzy fiesta. The arrival of the crabs has also brought a few of their close associates to the area, including the first bluefin tuna to come into the Monterey Bay in a decade!"
Which is nothing to be crabby about.