Taking the lab to the field
Research in many terrestrial habitats called FACE (Free Air CO2 Enrichment) experiments were performed over decades to explore how an increase carbon dioxide will affect plants on land, from forests to deserts to grasslands. These FACE studies have been a key approach in understanding the likely consequences of global change on terrestrial plant communities.
George and his colleagues were inspired to try a similar experiment in the ocean, creating a Free Ocean CO2 Enrichment (FOCE) system to look at the effects of increased carbon dioxide concentrations on marine animals. They put a clear plastic box in the ocean—sort of an underwater flume—pumped in carbon dioxide to raise the seawater’s acidity, and observed the animals inside.
“The idea of the chamber in the ocean is to open up the whole system to as many potential variables as possible,” George says.
As on land, the approach has been tried in a variety of ocean locations and habitats, from off the coast of France to the Great Barrier Reef, and from waters more than half a mile deep to just underneath Antarctic ice.
“MBARI has had a hand in pretty much every one of these efforts,” Jim says.
Local challenges
One area that’s been difficult to study is visible from the Aquarium’s back deck, looking out toward neighboring Hopkins Marine Station. It’s about 20 meters below the surface, in a sandy spot near a kelp bed.
The challenges at this site include relentless wave action, sand that’s constantly moving and poor visibility. There are also animals “curious and nimble enough that we’ve had to put locks on the [flume] opening,” George says. Crabs left in a clear box are evidently enticing to predators, although the researchers aren’t sure whether seals, sea lions or octopuses are taking advantage.
Then there’s an apparent leak in the hose—roughly 1,000 feet long—that pumps treated seawater from the Aquarium out to the chamber. The team has been waiting for calm conditions so divers can find and patch the leak. George and Jim expect to get the system online by summer.
George hopes to study the impact of changing ocean chemistry on sanddabs, a type of small flounder that’s abundant—and an important commercial seafood species—in Monterey Bay.
The resulting data may help the public and policymakers better understand what a more acidic ocean will look like, and what we can do about it.
“Coral reefs around the world are disappearing, due mostly to global warming,” Jim says. “In addition to their importance as sources for fisheries, biodiversity and ecotourism, the loss of coral reefs will remove the shoreline protection afforded by offshore reefs, leading to increased storm damage to coastlines.”
Acidification could also inhibit the reproduction of commercially raised shellfish, affecting a source of seafood needed to help feed a growing human population.
Learn more about MBARI’S ocean acidification research.