Game-changing

A Bay Area scientist made a game-changing find — entirely by accident

'I initially didn't want to have anything to do with them, to tell you the truth'

By Kasia Pawlowska

Brent Hughes, an assistant professor of marine ecology and conservation at Sonoma State University, is a self-proclaimed “algal nerd.” But last week, while speaking at a Garden Club of America event, he wasn’t just talking gardens or algae — he was talking otters.

Hughes’ dive into studying otters was accidental. While studying eelgrass at San Jose State University’s Moss Landing Marine Laboratories around 2008, he noticed the marine plant was actually starting to recover amid a large, normally destructive algal bloom.

“It was bizarre,” Hughes told SFGATE over the phone after the Garden Club of America meeting. “We didn’t immediately go, ‘Oh, it must be the sea otters.’ That was literally the last thing [we considered].”

He tried to find an explanation — El Niño, seasonal temperature fluctuations — yet there was nothing to account for the abnormality. The “a-ha” moment finally took place when he got hold of a data set from a tour operator at Elkhorn Slough Safari, which operates out of Moss Landing.

“Capt. Yohn was giving all the tourists on the boat little hand counters, you know, the clickers?” said Hughes. He instructed passengers to click every time they saw a sea otter, so they could later compare who saw the most. “He was doing this almost every day, sometimes several times a day, for 15 years, and he was actually recording the data.”

An unplanned career shift

Hughes had been on the brink of giving up on his eelgrass study and had no idea he was about to make a startling discovery when he overlaid the sea otter data with the area where the marine plant had recovered.

“They kind of followed each other in time, and it was almost like the two time series fit together like a glove,” said Hughes, recognizing that the creatures were somehow positively impacting the underwater meadows. After that, he knew he had to keep following the furry carnivores.

“It was totally by accident and serendipity,” he said. “I’m a little bit different from most sea otter biologists or ecologists because most people want to study sea otters, but I initially didn’t want to have anything to do with them, to tell you the truth.”

The discovery led Hughes and his team to start a study in 2013 about the salt marsh at Elkhorn Slough and the sea otters’ impact on it, which was finally published this year in the February issue of the journal Nature.

Now, his focus is decidedly more esoteric: “I basically study sea otters where they don’t currently exist.”

Bringing sea otters back to the bay

North of San Francisco, people don’t see sea otters in the wild often. They do show up once in a while — usually juvenile males swimming up from Monterey — but functionally, they don’t reside here. So Hughes, along with a number of other scientists, agencies and nonprofit organizations, has been studying San Francisco Bay and other estuaries surrounding Point Reyes National Seashore.

“We’re asking the question, ‘Well, would this be good for sea otters?’ And then if so, what would be the impact of the sea otter potentially returning here?” he said. Hughes and his team published a paper in 2019 in the journal PeerJ that shared a model predicting that San Francisco Bay could currently support about 6,600 sea otters. While the number seems exciting, it pales in comparison to the estimated tens of thousands of sea otters the region once had.

Hughes’ other recent studies have focused on the risks facing the sea otter in San Francisco Bay — and there are plenty. Between boat traffic and contamination, it’d be a very treacherous place for sea otters to reside. The possibility of a habitat farther north offers more hope.