A pandemic-era crush of new interest in clamming on the California coast and widespread adoption of simple hydraulic pumps that allow people to harvest the shellfish faster and in greater numbers has put abundant clam stocks in newfound jeopardy, prompting state regulators to step in with emergency prohibitions.

The state Fish and Game Commission this month temporarily banned use of the hand-operated, water-squirting pumps that have become the dominant tool of clammers since their introduction about five years ago. The pumps have allowed more shellfish prospectors to haul in their limit of clams, day after day, and helped fuel illegal harvesting of noncommercial species that are winding up on the black market, officials say.

Use of the hydraulic pumps was growing so quickly that regulators feared they might be too late if they allowed the busiest season of the year to come and go before they took action on the devices. A 2019 survey of clams taken in Tomales Bay, one of the state’s hottest clamming areas, showed 85% were obtained with the use of the new tool, which earlier surveys showed coincided with more frequent bag limits.

“It’s not to say we won’t allow it in the future, maybe under some restrictions,” said Sonke Mastrup, environmental program manager for the state Department of Fish and Wildlife’s invertebrate program. “We just need time to explore it before we let things get any further down the tracks.”

The emergency rule, adopted Feb. 10 by unanimous vote of the state Fish and Game Commission and set to take effect in early March, temporarily bans use of the two-man pumps for as long as a year so the agency can analyze their impact on intertidal clam populations.

State Fish and Wildlife personnel said they view the emergency action as a stop gap measure, given a spike in clamming activity since the start of the COVID-19 pandemic, when shelter-in-place restrictions sparked heightened enthusiasm for outdoor recreation, including visits to the coast.


Wardens are reporting an uptick in citations for illegal conduct facilitated by use of the pumps. That includes cases of individuals trying to pass off buckets of the shellfish as if collected by a whole group when, really, it was two people on a pump who got them all, officials said.

The clams are less frequently chipped or damaged as well, lending themselves to ready sale on the black market, where they have been passed off as high-value geoduck clams from Washington that can garner $30 to $40 a pound, Mastrup said. Game wardens have seized hauls of clams that have been rubber-banded — a trick that helps keep the water inside them, adding to their weight, officials said.

They believe illegally commercialized clams are filling the vacuum left by black market abalone, which have become harder to poach since the sport harvest was suspended in California beginning in 2018.

Pumps ease search, boost harvest

Even law-abiding citizens are making a much bigger dent in the resource than was previously possible.

Through use of the hydraulic pumps, clam prospectors have been able to ease the difficulty of digging up the shellfish, one of the chief obstacles that limited harvests and preserved stocks. And with the pumps catching on among a greater number of users, more people are likely to get a daily limit — and do so repeatedly throughout the season, officials said.

Clam-digging activities also have pushed into wider areas, extracting bivalves that previously were inaccessible and served as “de facto reserve populations,” while also putting protected eelgrass beds at risk, Mastrup and others said.


“The popularity of this pump really exploded,” Mastrup said. “So whenever you see a big shift or, in this case, an increase in recreational take of something that’s been kind of on autopilot at a stable state, you think, ‘OK, this might not be safe.’ “

Two classes of clam are legal to sport fish in California: gaper clams and Washington clams, both of them commonly harvested along the mud flats in Bodega Bay and, especially, Tomales Bay in Marin County. The latter, along with Humboldt Bay, has traditionally been one of the state’s most popular among about a half-dozen common clamming areas, according to state Fish and Wildlife.

Immature clam larvae settle at least a foot or two under the mud or sand, where they mature, growing to as much as 5 pounds. Tubelike siphons that extend to the surface allow them to filter food out of the ocean water. When the tide is out, their siphons make tiny holes on the surface of the beach or exposed sandbars, like the islands that appear at low tide in Tomales Bay, marking the clams’ presence.

Traditionally, clam diggers will use a shovel to remove the sand or soil around them — sometimes inserting a wide, stiff tube to prevent the area from caving in — until they get to the shellfish. A “good sportsman” will fill up the hole after harvesting a clam to protect any smaller clams around it, said Willy Vogler, a co-owner of Lawson’s Landing on Tomales Bay.

The hydraulic pumps look like large bicycle pumps and are typically assembled from parts available at most hardware stores, though increasingly they are turning up at tackle shops and elsewhere, Fish and Wildlife personnel said.

They include a cylinder with a water inlet at the base, compressor handle and a flexible tube with a rigid nozzle used to shoot a pressurized stream of water into the sand or mud flats around a clam. This liquefies the substrate, allowing the clammer to just reach for the targeted bivalve rather than having to dig down to one.


Since the base of the pump needs to be in several inches of water anyway, it also allows for clamming before and after low tide, as well as in areas that aren’t fully exposed during low tide.

Participants typically wear wet suits, with one lying in the water directing the nozzle and collecting clams. Being partially submerged also lends itself to concealing illegal conduct, including taking more clams than daily limits allow or high-grading for size — tossing smaller, legal clams back only after securing larger ones, which is illegal and nearly always results in the death of a clam that’s been dug up. By law, clam diggers can only keep the first 10 legal clams they dig up.

Harvest limits flouted

Fish and Wildlife personnel said wardens working in Tomales Bay on Saturday, Jan. 9, observed 180 people digging clams during an afternoon low tide, many of them working in teams with hydraulic pumps. Six groups contacted were cited for removing more than their allowed limit. The next day, 50 clammers came, and all the groups contacted were cited for high-grading, the agency said.

Wardens find they’re contacting and citing some of the same people time after time, Fish and Wildlife Lt. Ed Morton said.

On a single day last fall, seven poachers were fined between $582 and $3,372 for overtake of clams in Marin County Superior Court, Morton said.

“That’s almost $11,000 in fines, and people are continuing to do it, so that’s very concerning for the resource,” he said.


Even if everyone makes only his or her legal limit, the overall pressure on the clams is greater, since many, maybe most, clam diggers would go home without a getting a full bag limit using traditional means in the past.

A 2017 count of clammers conducted during low tides over three months put daily numbers between 339 and 554 people at Tomales Bay, state Fish and Wildlife said. Clam diggers need only a fishing license and don’t need to report their catch, so there is no real available harvest data, said Ian Kelmartin, an environmental scientist with the agency.

But if 400 people collected 10 clams each, that’s 4,000 a day — 8,000 if they are collecting 10 of both kinds.

Rush depletes shellfish stocks

Vogler, whose family’s operation at Dillon Beach has featured clam digging as a main attraction since the 1950s, said the impact has been clear.

Restrictions imposed by the California Coastal Commission cap Lawson’s Landing at 100 vehicles a day, but Vogler said it’s still possible to see that many more clams have been harvested over recent years, in part because of bigger groups coming through, with bigger buckets full of clams.

“Where there used to be just clams everywhere, like a carpet of clams, it’s not just that they’re getting hard to find, but there’s more space between them, and the size is going down,” he said. “Everyone around here, everyone who worked the landing, could see that it was happening.”


Something similar happened back in the 1990s, when visitors could ride the Lawson’s Landing Clam Clipper barge out to the sandbar for $10 a pop, 120 people at a time, eventually resulting in such diminishing clam numbers the barge was docked, Vogler said.

Vogler already had become concerned about increased harvests and use of the hydraulic pumps in 2019, as were Fish and Wildlife wardens, who were increasingly busy issuing citations and staging undercover enforcement actions. When Vogler consulted with the agency, they suggested he petition the commission to consider enacting restrictions on the hydraulic device.

The emergency approach was proposed when it became clear just how quickly the pressure on the clam population was exploding, Kelmartin said. “We’re not sure that it’s sustainable,” he said.

The emergency regulation prohibits use of the hydraulic pumps for the harvest of clams, sand crabs and shrimp, and requires each person to keep their clams in a separate container. It was approved for a 180-day period, with two possible 90-day extensions. Suction devices known as “shrimp guns,” “slurp guns” or “clam guns” are still allowed.

It is expected to take effect around March 8.