Major shoreline project transforming San Francisco's Presidio, could benefit sea life habitat

ByDan Ashley and Tim Didion KGO logo
Saturday, July 11, 2020
Sea life habitat built into Presidio project
A major shoreline restoration project is transforming San Francisco's Presidio. It's a melding of architecture and ecology that could have major benefits for sea life.

SAN FRANCISCO (KGO) -- Anyone can see the massive changes in the works near San Francisco's Crissy Field. But hidden in this historic shoreline restoration is what you might call the world's tiniest affordable housing project.

"But it's perfect for the kind of life we're trying to attract to the marsh," says project manager Genevieve Bantle of the Presidio Trust.

A team of engineers, architects and biologists are joining forces up to create a cutting edge sea life habitat. It's being built right into the cement culverts that will feed a newly restored marsh area, flowing between the Bay and the Presidio.

Besides a rougher surface, the cement is also being fitted with movable fiberglass panels to give oysters and other sea creatures an additional anchorage to attach themselves to. The design was developed by researchers from the California College of the Arts, who tested the concept underneath their floating lab, anchored in San Francisco Bay. The result is a kind of bio-design architecture.

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"As the Bay was developed over the last century plus, we lost a lot of structure, a lot of the Bay shoreline is gone," says Jonathan Young, a wildlife ecologist with the Presidio Trust.

Young says the oyster friendly panels are only one of the ways they're creating habitat in the marsh, which is known as Quartermaster Reach. High in the Presidio's hilly slopes, Young and his team have been crushing oyster shells, donated by local seafood restaurants. The broken shells are being re-cast into pods that will form a kind of reef, attracting oysters to its calcium rich crevices when they're placed in the water.

"These baby larval oysters that are floating around, they're going to find them, and they're going to settle and kind of create this feedback loop of more oysters are going to attract more oysters and so on and build up this reef naturally," Young explains.

Back at the construction site, nearly three dozen fiberglass panels are schedule to be placed in the cement culvert. The crushed-shell oyster pods will be placed separately. If successful, the project could help bolster the marine food chain, helping to bolster a thriving ecosystem from the Presidio to San Francisco Bay.

"And will really create a unique place for the people of San Francisco," says Genevieve Bantle.

Once the fiberglass panels are in place, researchers say they'll still be able to move them around, to find the best locations for the oysters to thrive.