An underwater robot is now charting the eelgrass meadows that carpet the floor of Richardson Bay, the first step in a plan that could bring nearly $2 million in new funding to restore the ecologically vital seagrass off Tiburon's waterfront.

The Richardson Bay Regional Agency began deploying the drone in August to map and monitor eelgrass beds across the bay. The agency has applied for a $1.9 million grant that would fund a second phase: using robotics to actually replant eelgrass, as The Ark first reported Wednesday, Aug. 5. For now, the robot only surveys.

If awarded, the grant would exceed the agency's entire annual operating budget, which stood at roughly $1.84 million as of 2023.

Why eelgrass matters here

Richardson Bay holds the second-largest eelgrass bed in the San Francisco Bay estuary. The bay as a whole contains one-third of all California eelgrass, according to the RBRA.

The seagrass supports fisheries, reduces erosion, sequesters carbon and provides feeding and resting grounds for harbor porpoises, seals, sea lions and tens of thousands of migratory waterbirds traveling the Pacific Flyway. It also filters water and buffers the shoreline against storms.

For years, illegally anchored boats damaged the beds. Anchor chains dragged across the bay floor "like a lawnmower," according to a 2024 statement from Rep. Jared Huffman's office, scraping away plants and leaving barren "crop circles." About 80 acres of eelgrass was lost.

Restoration already ahead of schedule

The robotic mapping builds on a restoration effort that has outpaced its own timeline. Funded by a $2.8 million EPA grant awarded in 2023, the RBRA and its partners had planted 14.5 acres of new eelgrass by July 2025, just a half-acre short of the 15-acre goal originally set for 2027.

"We continue to see positive change on Richardson Bay," Executive Director Brad Gross said in a July 2025 agency statement announcing the milestone. "Whether it's pulling two tons of marine debris off the Bay floor, or planting nearly 15 acres of eelgrass, we are helping to restore a healthy environment here for everyone to enjoy."

The partnership includes Coastal Policy Solutions, Merkel & Associates, Audubon California and Kathy Boyer's lab at San Francisco State University's Estuary and Ocean Science Center on Paradise Drive in Tiburon. Keith Merkel, president of Merkel and Associates, called the Richardson Bay effort "the largest successful eelgrass restoration in the Bay" in the same July 2025 release.

In May 2025, divers removed approximately 4,200 pounds of debris from the bay floor, including two sunken boats, marine batteries, outboard engines, a PlayStation, a microwave and an office chair.

Protection zone cleared

The Eelgrass Protection Zone, an area of Richardson Bay off-limits to anchoring, was established in October 2024. By March 2026, the last illegally anchored vessel had been removed. In 2022, more than 100 boats sat in what is now the protected zone.

The RBRA serves Belvedere, Mill Valley, Tiburon and unincorporated Southern Marin. The agency has not announced a timeline for the $1.9 million grant decision or the next phase of robotic planting.