SANTA CRUZ — Ocean acidification has been called the “evil twin” of global warming because the same carbon dioxide emissions that cause climate change also dissolve into seawater, threatening the world’s oceans. And the biologically rich Monterey Bay is more at risk than most bodies of water.
The reason is that the California Current, spanning the west coast of North America, is acidifying twice as fast as the rest of the world’s oceans. Globally, the oceans are already 30 percent more acidic than they were 200 years ago. By the end of the century, scientists say, they are expected to be 150 percent more acidic. But experts predict that Monterey Bay might reach those levels much sooner — in only 35 years.
“If the oceans die, we die,” said Jason Scorse, director of the Center for the Blue Economy of Monterey. “And if the oceans die, it’s mostly going to be (because of) ocean acidification.”
Most of the attention at the international conference on climate change in Paris — which concluded Saturday with a historic deal to cut greenhouse gas emissions — focused on global warming. But marine biologists and many environmentalists say that they were happy to also see serious discussion of the “sleeper” issue of ocean acidification, which threatens entire food webs and ecosystems.
Scientists and public officials say that human life depends on healthy oceans — which regulate climate, provide half of the world’s oxygen and supply people with food, jobs and recreational activities. Entire economies are built around oceans, which create 2.9 million jobs in the United States — a half-million of those in California.
“We are tied to what we eat and drink — and how we interact with our environment,” said Charles Boch, a marine biologist at the Monterey Bay Aquarium and Research Institute, or MBARI.
Monterey Bay is particularly threatened from ocean acidification because of the natural process of upwelling — which brings the cold, deep water from arctic currents to the surface. That cold water is naturally more acidic than the Pacific’s surface waters.
Upwelling also churns up nutrients that draw in fish, whales and other marine life, feeding Monterey Bay’s vibrant ecosystem. So, in a cruel irony, the same phenomenon that sustains the bay also makes it more vulnerable to ocean acidification.
“Animals come from all over to eat here,” said Andrew Devogelaere, research director of the Monterey Bay National Marine Sanctuary. “Turtles swim from Indonesia to eat our jellyfish. Birds fly from New Zealand. Monterey Bay is special because of the rich nutrients, rich sea life, the diversity of sea life and the diversity of habitat.”
But scientists are alarmed about the potential damage to marine life because oceans act like sponges, absorbing carbon dioxide from the atmosphere when it is released from burning oil and other fossil fuels. Upon contact with water, the carbon gas interacts with molecules in the water, forming an acid that eats away at not only coral but also the calcium skeletons of sea animals with shells, like oysters and abalone.
And scientists are particularly interested at studying impacts of increased acidity on juvenile marine life. It’s especially hard for the young animals to grow their shells, which dissolve in the acidic conditions. Boch has found that increased acidity lowers fertilization rates in the red abalone, a culturally and commercially important species in California.
“I grew up on the coast of California, and I have a lot of great memories of great interactions with the ocean, fishing, surfing or just even swimming,” Boch said. “Over time, even within my lifetime, things have changed. We can’t get abalone in Southern California, not commercially and not recreationally. That has gone away in our lifetime. I think that’s really sad. That’s just one case.”
Juvenile rock fish cannot swim as well in more acidic conditions, said Susan Sogard, with the Southwest Fisheries Science Center in Santa Cruz. That was the conclusion of a study she worked on with Scott Hamilton, a MBARI scientist.
The condition is nonlethal, Sogard said, but it may affect the survival of the species because the young fish might have trouble swimming away from predators or finding food.
“Whether it’s the plant kingdom or animal kingdom, the younger you are, the more vulnerable you are to the world,” Boch said.
California’s oyster farmers have already been affected, as the oysters struggle to make their shells. The farmers depend on hatcheries for “seed,” or baby oysters. And 10 years ago, they found that the survival rate of the young oysters had dropped dramatically, forcing farmers to increase prices.
“It’s this worrisome thing that there could be an endgame for the way we are operating now — that we won’t be able to naturally grow oysters in the bay,” said Martin Seiler, manager of the Tomales Bay Oyster Company in Marin County.
Another threatened species is crustose coralline algae, which grows on the rocks in kelp forests and provides a surface for other animals to grow. “It provides the glue that holds things together,” said oceanographer David Koweek, a Ph.D. student at Stanford University. These organisms have a calcium similar to coral skeletons, but are even more sensitive to acidic conditions.
Kristy Kroeker, a marine biologist at UC Santa Cruz, hopes to understand how Monterey Bay will look in the future with increased acidification. In her previous research, she has seen profound shifts in sea communities that change from colorful and diverse, to empty and unable to support the healthy growth of flora and fauna.
“The kelp forest ecosystem likely won’t crash entirely,” Kroeker said, “but there will likely be a loss in biodiversity.”
The ultimate answer is to reduce carbon emissions globally, but Monterey Bay scientists are already searching for more immediate solutions, such as planting more sea-grass meadows that naturally grow inshore of kelp forests, Koweek said.
When sea grasses photosynthesize, they take carbon dioxide out of the water, similar to trees taking carbon dioxide out of the air we breathe. And the scientists at Stanford’s Hopkins Marine Station are working on this in the water right outside their Monterey offices.
These interventions are helping to buy these animals time now while the world works on reducing emissions in the long term, he said.
Koweek said animals in coastal ecosystems have the ability to adapt, “but a fear with climate change and ocean acidification is that we are changing so fast that we are exceeding organisms’ ability to adapt.”
To address the issue, Reps. Sam Farr, D-Salinas, and Lois Capps, D-Santa Barbara, this year introduced the Federal Ocean Acidification Research and Monitoring Act to expand National Oceanic and Atmospheric Administration’s efforts to study the impacts. But the bill has stalled in the GOP-controlled House.
“The warning signs are coming out of this bay,” Farr said. “It’s alarming that the national politics isn’t listening. If we continue along this process, we are killing the oceans.”
