U.S. Navy, Port of San Diego monitoring health of San Diego Bay eelgrass

All across San Diego Bay, you can see what’s obvious: Navy carriers, the shipyard, other port facilities, and, of course, just how beautiful San Diego Bay is. What you can’t always see is something really important to the health of the bay, but it’s below the surface.

“Here in San Diego Bay, I believe we have one of the healthiest bays up and down the coast,” Frank Ursitti, a managing partner of H&M Landing in Point Loma, said.

For Ursitti, that’s important for his industry, and for all anglers and the fish they reel in too.

But there’s one ingredient to the strength of the bay they can’t always see.

”Healthy eelgrass ecosystem creates a healthy bay ecosystem,” Jessica Curran, a marine biologist with Navy Regions Southwest, told NBC 7.

Eileen Maher, Director of Environmental Conservation for the Port of San Diego, would say the same thing, too. Both agencies have been working on conserving and expanding eelgrass habitats across the San Diego Bay.

“It’s the base of the food chain for San Diego Bay,” Maher said.

The long, thin blades of eelgrass are found around the perimeter of the bay. Sometimes 0.5 ft. deep, according to Maher. Curran says they typically reach 12 feet below the sea surface but have been found as deep as 20 feet.

They’re also at the base of the food chain, filtering water and absorbing carbon. But they play an even bigger role in the lives of humans than you might think.

“It provides habitat for, as a nursery, for juvenile fishes, for invertebrates, and those species grow up to be large fishes and large invertebrates and the types of things that we eat,” Curran said. “So, eelgrass is directly connected to providing habitat for recreational and commercial fisheries.”

The United States Navy and the Port of San Diego have been monitoring the eelgrass since the 1990s. According to Curran, it’s part of the San Diego Bay Integrated Natural Resources Management Plan.

 “That is a joint document that is really a road map that talks about how each agency separately and together are going to manage their resources in the bay,” Curran said.

Curran added that by protecting the eelgrass, the Navy is supporting the military mission and balancing environmental stewardship and minimizing their impact.

For Maher and her team, this work falls in line with the Port’s Tideland Trust.

“Our Tidelands Trust requires us to balance commerce, recreation, fisheries, navigation, and environmental stewardship,” Maher said “I think we do that very well.”

According to Maher, San Diego Bay has 2,600 acres of eelgrass. That’s about 50% of all the eelgrass in Southern California and 17% across the state. Although you can’t always see its impacts, according to the Port of San Diego, eelgrass beds in the bay can store 1.7 million metric tons of CO2. That’s nearly the same amount nearly 370,000 emitted annually.

“So it takes those impacts away from the atmosphere and puts it into the base sediments,” Maher said.

Maher says the goal is to expand the habitats, but the older beds have the ability to store more carbon.

“So it helps to pull it out of the atmosphere and it’s a food source for the eelgrass, it’s in shallow habitat because it also needs sunlight,” Maher said. “Because like normal plants, it also uses photosynthesis and the sun’s energy for nutrients.”

When it comes to protecting these plants, these agencies are mapping and tracking the growth of eelgrass, protecting it during construction projects across the bay, too.

“Where it is, where it’s not, how it’s changing over the years, so we can take that information and use that to plan where we’re training, where we’re operating, also our shoreside construction on our shoreside facilities that we can either avoid or minimize impacts to eelgrass,” Curran said.

And since this monitoring all started, and most recently, their work has been a success.

”It’s been really cool over the last couple years that we’ve done the eelgrass surveys, that we’ve seen it really go into these places it’s never gone before,” Curran said.