It’s a one-of-a-kind census effort on the California Coast that started nearly a decade ago. It asks: How is the population of an endangered species of fish faring?
"A Giant Sea Bass has the same life history essentially as a human. The longest we have seen is 76 years, and it can get up to well over 600 pounds," said Andrew Pettit, a researcher with UC Santa Barbara’s Benioff Ocean Science Laboratory. "Because they live such a long time, and have such a long time before they can reproduce, they're a slow-growing species and are really susceptible to going extinct or being overfished."
He said the fish are an important barometer of ocean health.
"The Giant Sea Bass, as an apex predator, helps regulate the kelp forest and manage both the prey population and any of the basal resources," explained Pettit. "When you don't have this apex predator, you don't have the ecosystem in check, and it's exactly like a canary in the coal mine when the ecosystem starts to get out of whack."
How do you tell how the Giant Sea Bass are doing? Researchers decided you catch them, not with a spear gun or net, but with cameras. To do that, they would enlist the aid of Southern California’s diving community.
"The question for years was how on earth are we going to be able to determine the population of an elusive fish that is endangered?" asked Pettit. "We realized that Giant Sea Bass have unique spots, and this is huge, because we were actually able to identify them underwater in a non-invasive way. They're also an iconic species within California, within the recreational diving and fishing community.
"With the introduction of social media and images, we can outsource this idea to the public so they can actually submit their own photos of Giant Sea Bass," said Pettit.
Phil Garner is among the divers who have also become citizen researchers.
"Diving in Southern California, most of the fish are tiny little dots to less than a foot long," said Garner. "All of a sudden, here comes a fish that outweighs you by a few hundred pounds. It's like the Goodyear Blimp floating underwater, coming up right to you."
Garner added that over the last few years, he's photographed nearly 200 Giant Sea Bass. "A lot of the fish, we'll recognize, because we see them all the time, and they actually come up, and look at their reflection in our camera ports."
The researchers developed a formula using the photos to calculate the number of fish living in the ocean from Point Conception to Mexico.
"It's been a huge success. A lot of the divers submitted photos. I think there are over 300 community scientists to date, " said Pettit. We now have over 2,000 images of this incredible species."
According to Pettit, they’ve discovered some Giant Sea Bass, which are especially photogenic, and have been captured on camera multiple times.
"Whenever a person is able to submit a photo, they get an alert, saying, okay, we have identified this fish," said the researcher. "So, let's say you've identified 'GSB-100.' If that fish is reseen, the person gets an e-mail saying your fish has been reseen here."
Pettit said it’s heartening that the Giant Sea Bass population is increasing. The study estimated that there were about 1,200 of the fish in the region between 2015 and 2022.
But a century ago, before overfishing, there were tens of thousands. In the 1930s, an estimated 4,500 were caught off our coast annually.
The now limited population has also raised concerns about their biodiversity. The researchers feel we have a long way to go to get the population of the fish back to normal.
