Over the past week, Hofmeister and a team of divers from the Bodega Marine Laboratory have been performing predator surveys in a range of stocked habitat plots along the California coastline. Last year, to test the waters, the team released 3,200 farm-raised red abalone in Long Beach—a process they call outplanting. “We saw a very quick and immediate increase in octopus right next to our abalone a few days after we put them out there,” Hofmeister says. “We call it ‘ringing the dinner bell’.”

Octopuses are abalone’s most voracious predator in deep water, but crabs, lobsters, and fish will target them, too. Captive-bred abalone released into the wild, researchers theorize, are stressed in their new environment and haven’t developed fast-acting fear responses yet. The abalone’s first lines of defense are passive: camouflage and a hard shell. If pursued by a slow-moving predator, like a starfish or predatory snail, abalone can retreat, if only at a literal snail’s pace. When faster-moving threats approach, abalone can engage their mollusk death grip, clamping down on a rock and holding on for dear life. But studies show that farm-raised abalone don’t clamp down fast enough. And even if they do, some predators, like octopuses, are able to bore through their shells.

Hofmeister pulls out her waterproof chart and begins performing casual necropsies on each of the red abalone shells she’s collected. “Damage to the shell can give us an indicator of what ate it,” she says, picking up a tiny green and gray shell with chips along the edge. “This was probably a crab or a lobster, because they’ll use their sharp claws to flip the abalone off the rock.” Octopus kills, she continues, can be identified by the pin prick-sized hole it makes through the middle of the abalone shell with its rasping tongue to reach the main muscle, where the octopus injects a paralyzing toxin. This allows the octopus to pry the abalone off the rock and devour it. “There is not much we can do to increase the armor of the abalone,” Hofmeister says. “If we can find a way to deter octopus, that might be our best bet.”

So far, about 700 of the 7,200 outplanted red abalone from the trial have been accounted for across nine sites in coastal Los Angeles and San Diego, 400 of them dead and 300 alive. The site Hofmeister is monitoring today seems to be showing better survival rates than other locations as well as fewer predators. As she packages each abalone shell in a small plastic bag, another dive team swings by in their boat and passes over a white plastic bucket containing a California two-spot octopus (Octopus bimaculoides) collected at one of their survey plots.