Along the beaches of northern California, and the past year has seen a boom in crowds on the hunt for one of the region’s favorite edible delights: clams.
But among the buckets and shovels, clam hunters are increasingly coming armed with a powerful new tool: hand-operated, water-squirting pumps that allow them to take more clams, faster than ever before.
The surge in the use of these hydraulic pumps, which have the capacity to collect a day’s worth of clams in just a few minutes, has raised concerns about their effects on the coastline and clam populations. As a result, the state is cracking down – opting in March to temporarily ban their use until the impact can be fully understood.
“With any good fisherman, you’re always looking for a better tool,” says Sonke Mastrup, an environmental program manager at the California Department of Fish and Wildlife. “Clamming has been at a steady pace for a long time. A couple years ago we had to close down the abalone fishery because the collapse of the kelp forest, and a lot of the abalone pickers shifted to clamming.”
Fishing and hunting license sales increased 10% in California during the pandemic, reversing years of decline. Clamming has grown in popularity for several reasons: people are looking for safe activities to do outdoors, but also some are clamming for subsistence and trying to get money from selling the shellfish (which is illegal without a commercial license). The most common clams dug on the beaches are Pacific gaper clams, fat gaper clams, and butter clams. They can make a tasty dinner alone or chopped up in a clam chowder.
The new hydraulic pumps work like a bicycle pump, liquifying the sediment around the clam and allowing people to easily pick them up in shallow water. A team of clammers can catch their allotted amount of gaper clams and butter clams in just minutes. Legal catch limits are 10 per day.
While the pumps aren’t a new problem, their prevalence has risen. Two years ago, Mastrup says, you might see one or two pumps among 50 groups. But this year, about 80% of the clammers are using the hydraulic pumps.
That can be a problem because the pumps are just too efficient, meaning clammers hit their daily limit very quickly. They don’t often bury the smaller clams they’re not taking home, and leaving them on the warm sandy beach can kill them. Using the pumps can disturb the eelgrass bed – floating underwater plants that play an important role in feeding and sheltering creatures – since the catchers are often walking in shallow water rather than standing on the shore.
“If you were digging, it takes a few minutes to pop out a clam, but it takes only 10 to 15 seconds with the pump,” says Mastrup. “The clams come out beautiful, with no shovel cuts. As a clammer I’m jealous, but as a resource manager, it might be too good. Our clam fishery was sustainable with the old tools and methods.”
These local clams, including gapers and butter clams, take about three years to mature fully and can live to a whopping 20 years.
There has been an increase in tickets during the pandemic due to illegal commercial selling and people taking over the legal limit, Mastrup says. The state has written tickets for people selling gaper clams illegally as geoducks – a particularly valuable relative that lives in the Pacific north-west and doesn’t look much like the more common gapers. “There’s a big difference but most people don’t know the difference, and they were getting $30 to $40 pound off gapers,” he said.
And while clam populations have typically been stable, Mastrump says there are concerns the pumps are destroying the clam beds and could disrupt next year’s supply.
Clams aren’t the only coastal species under pressure from collectors. Farther south, Jennifer Burnaford, a marine ecologist at Cal State Fullerton, has been monitoring rocky habitats where mussels cling while waves pound the shore. During the pandemic, people flocked to areas to pick mussels, sometimes because they were looking for an inexpensive way to feed their families – putting strain on the delicate ecosystem.
One of her students has been studying the impact of climate change on the ability of mussels to attach to rock surfaces by counting and measuring the creatures. It turns out this work also enabled her to gather data on the distribution of the mussels at various locations before and after the pandemic shellfish-gathering surge.
The data show that large mussels, over 50mm in length, are largely gone, though the smaller ones are still present. Bigger mussels have more reproductive output than smaller ones – so the ones who remain won’t produce as many offspring. Another effect of pulling out bigger mussels is that they use protein anchors to attach to the rock surface and to each other. When removed, that can weaken attachment to all the others, Burnaford says. “Yanking the big ones up can have a cascading effect on everyone else.”
Burnaford is quick to say that the scientists can’t attribute a definitive cause to the decline in the larger mussels, though it’s been documented that there are quite a few people going out and collecting mussels at the site she’s been studying. Burnaford is part of of a multi-agency group monitoring rocky ecosystems on the US west coast that is trying to answer some of these tricky questions.
She hopes a social media campaign and wardens educating people will help the visitors understand just how special the coastline is. The intertidal zone is full of these amazing organisms that can tolerate air, sun, and full-strength sea water. “People don’t even know they’re alive – you look at a barnacle and it’s a bump on a rock but that’s a living organism. I want to make sure people can learn about what’s out there so they don’t accidentally or inadvertently harm something.”