Oyster racks pulled in cleanup of Drakes Estero
A pint-sized hydraulic excavator, dwarfed by its setting in the wild, windy expanse of the Point Reyes National Seashore, is slowly extracting the last remnants of eight decades of oyster farming in Drakes Estero.
On the 54th anniversary of the seashore’s creation in 1962, the excavator on Tuesday rode aboard a barge on the shallow, 2,500-acre estero, yanking waterlogged wooden posts from the soft muddy bottom like so many bad teeth.
Nearly 7,000 pressure-treated posts, each driven 5 feet into the mud, supported oyster-growing racks scattered about the estero, built mostly in the 1950s and ’60s and left behind when the Drakes Bay Oyster Co.was evicted from the north end of the Pacific Ocean estuary at the end of 2014.
Hailed by wilderness advocates and still resented by many in the West Marin community and beyond, the oyster company’s exit set the stage for a cleanup by the National Park Service aimed at restoring the biologically rich estero to as close to a natural state as possible.
Removal of the 95 wooden racks, which stretch for a cumulative length of 5 miles and weigh nearly 500 tons, is the last major step in the restoration, along with removal of plastic, wood, metal and oyster-shell debris beneath the racks - a $4 million project that could take until February to complete.
All the oyster farm structures - a weather-beaten oyster shack, dock, workers housing and pavement - were scraped from the shoreline last year.
“It’s a milestone, a spectacular thing,” said Tom Baty of Inverness, a retiree and sport fisherman who personally collected more than 3,000 pieces of plastic oyster farming debris from the estero and seashore beaches in five years.
As part of the only West Coast marine wilderness south of Alaska, the estero “should have been cleaned up,” Baty said. “I’m thankful it’s happening.”
“This is a gift to future generations,” said Cicely Muldoon, the Point Reyes seashore superintendent. “I think people are going to enjoy the wild waters of Drakes Estero forever.”
The Park Service never considered leaving the racks or debris in the estero, a popular kayaking spot that abounds with fish, birds and harbor seals, “simply because that’s unnatural,” said John Dell’Osso, a park spokesman.
Moreover, those hard surfaces provided the footing for an invasive tunicate, a primative marine animal, the government hopes to eradicate. The hope is that eelgrass beds will grow into the bare areas below the racks.
“Leaving any of that behind was never really an option,” Dell’Osso said, referring to the manmade leftovers from commercial oyster operations dating back to the 1930s.
The floating excavator and crews from T.L. Peterson Inc., a Red Bluff-based contractor hired by the Park Service, started work last week, pulling the racks closest to the shore.
By Tuesday, about 10 of the 95 racks had been removed, with piles of soggy timbers laid on the shore to dry before they are hauled to a landfill that can handle toxic waste, Dell’Osso said.
Most of the wood was treated to withstand a saltwater environment and still holds arsenic, zinc, copper and a creosote-like substance.
Workers first cut the racks apart, using tools that do not produce sawdust, to access the posts. A chain attached to the excavator’s arm is then wrapped by a diver around the post and cinched tight as the arm lifts upward.
Some posts come out readily, while others, heavily caked in mud, put up more of a fight, Dell’Osso said.
Noise from the operation has been “minimal” and could barely be heard on shore, Dell’Osso said. Sediment stirred up by the post removal settles within an hour or two, he said.
When all the racks are gone, excavators will scoop remaining debris from the estero bottom.
The Park Service will monitor the eelgrass, tunicates and the estero’s harbor seal colony during and after the restoration project, with a host of agencies, including the California Coastal Commission, National Marine Fisheries Service, Regional Water Quality Control Board and California Department of Fish and Wildlife also reviewing the impacts.
The contract work period is set to end by February, prior to the start of the next harbor seal pupping period.
The $4 million project cost was equally split between the Park Service and a donation from the National Park Foundation.
Previous cleanup work, including removal of about 37,000 pounds of oysters, clams and debris from the water, cost about $500,000.