Underwater robot cleans trash from the floor of Monterey Bay

How do you fetch trash from the sea at depths that pop ears, strangle sunlight and draw ominous critters like jumbo squid and deepwater rockfish? Meet Phantom HD2.

The underwater robot, equipped with mechanized arms and piloted from a boat above, has begun policing the floor of Monterey Bay in search of old fishing equipment and whatever else is lingering hundreds of feet below the surface.

“We know there’s a significant amount of gear down there,” said Karen Grimmer, deputy superintendent for the Monterey Bay National Marine Sanctuary and head of the Phantom HD2 project. “Fish and whales have been known to get trapped in marine debris. If you think about it, fishing nets are very strong. They can entangle wildlife for decades.”

The new cleanup effort comes two years after the state created a network of marine reserves along the Central Coast. Phantom HD2 is helping maintain these protected areas for the sea life living there. This month the robot completed its maiden voyage and returned with two lost fishing nets that together measured more than 100 feet, an abandoned 20-foot gill net and a runaway crab trap.

“We want to try to revert these reserves back to their original condition,” Grimmer said.

From the giant plastic garbage patch in the Pacific to runoff from coastal communities to the equipment cast overboard from ships, ocean litter is a growing problem.

“There is literally nowhere at sea you can go to escape trash,” said Kaitilin Gaffney, a program director at the Ocean Conservancy, which conducts worldwide beach cleanups. “It’s found at the most remote of Pacific islands to both poles. We’ve literally cluttered the seas.”

What Gaffney calls “ghost fishing” — discarded nets and lines that continue to catch and kill fish — is one source of the problem she says can and should be addressed.

Already, efforts like UC Davis’ California Lost Fishing Gear Recovery program are targeting near-shore waters in Monterey Bay. Divers are scouring piers for tackle, and crews aboard fishing vessels are rounding up equipment farther out.

“But there are limits to how deep divers with scuba gear can go,” said Kirsten Gilardi, with the recovery program, which is partnering in the Phantom HD2 project. “Gear that is in deeper water we’re still figuring out how to remove with other technologies.”

Last week Phantom HD2 and its supporting 59-foot boat and seven-member crew visited the southern edge of the Monterey Bay Submarine Canyon, a conservation area known as Portuguese Ledge. The crew was armed with underwater video showing, among the plumed anemones, crabs, lobsters and sponges, discarded fishing gear, which it proceeded to remove.