Deep water seamounts are rich with diversity. Courtesy NOAA.

Video Expedition Hopes to Capture and Protect Deep Sea Diversity off Southern California

Once considered to be a cold, dark desert nearly devoid of life, the deep sea is now known to support more species of marine life than the shallow reefs of the tropics. A menagerie of corals, sponges and undiscovered creatures—some of them previously unimaginable, others known only from the fossil record, lies hidden in near complete darkness beneath hundreds, or thousands, of feet of water.

So, unlike the tropical coral gardens we’re all familiar with, the richest areas of the deep seafloor remain out of sight, out of mind, and largely unprotected. Geoff Shester, California Campaign Director and scientist for Oceana is hoping to remedy that to some extent. He is heading out on a five-day expedition to video document the diversity of deep sea life in the Pacific waters off Southern California. He’ll be part of a research team that includes members from the organization Marine Applied Research and Expedition which runs the remotely operated vehicle (ROV).

“Much of the West Coast seafloor north of Southern California has been flattened already by bottom trawling,” he says, “And we don’t know what we’ve lost because we didn’t know what was there in the first place. All we have is anecdotal stories of fishermen from years ago hauling up huge coral trees.”

Bottom trawling is the most destructive form of fishing that threatens marine biodiversity on the ocean floor. The huge nets trawlers drag across the bottom of the ocean are held open by heavy rollers and steel doors that weigh thousands of pounds. The gear scrapes up everything in its path from coral and sponges to many tons of unwanted fish and invertebrates that are thrown back dead or dying. 

The area where Geoff and the research team will be going near the Channel Islands is replete with underwater ridges and mountains that previous research has shown to be teeming with life. Recently, multi-beam sonar surveys from NOAA have revealed new reefs and rugged habitats that are likely hotspots for biodiversity.

“You can think of it like hunting for treasure,” Geoff says, “because there are still so many undiscovered treasures out there for biodiversity as well as places that are essential for the production of the fish that people do want to catch. Well, we just got the treasure maps that no one had before.” Searching the depths to 1,500 feet, the team’s remotely operated vehicle will capture video of that vast unexplored world. It will be just a tiny glimpse, but if it reveals a trove of diversity, Geoff says it will send an urgent message about the need to protect what lies beyond their scope. “Often times fishery managers will not believe data alone, but they’ll believe it if they see it in a photograph.”

Federal fishery managers are required to protect habitat essential to the survival and recovery of fish species. Oceana is working to expand current protections to close the entire remaining untrawled area of the Southern California Bight to bottom trawling. That’s about 16,400 square miles.

Bottom trawl fisheries off the U.S. West Coast target groundfish such as rockfish, sablefish, and Pacific cod as well as other species like prawns and sea cucumbers. In Southern California, bottom trawling has not yet expanded beyond nearshore waters, but Geoff says there is reason to believe it will as depleted stocks begin to recover and markets grow.

He stresses that the proposal is not just about protecting deep sea ecosystems for environmental reasons. These places provide vital habitat for commercial and recreationally caught fish species and are critical to sustaining the fishing industry and the lives that depend on it. “We’re not saying don’t fish. It’s trying to figure out how we can fish without ultimately depleting the source of what makes the fishery productive in the first place.”

“We can get out in front of that if we can show the footage, and document to the decision makers the reason we need to take a precautionary approach. Given the fragile, spectacular ecosystems at stake, we have an opportunity now to protect them before they are lost forever.”

The team heads out August 8th. We’ll keep you posted on what they find.