Bodega Marine Lab / UC Davis

Scientists from UC Davis are studying oysters and mussels to figure out if organisms will be able to adapt to climate change.

This week, scientists from around the world are meeting in Monterey to discuss what they call the “other” climate change problem: the oceans are becoming more acidic. It happens as oceans absorb the carbon dioxide we add to the air through burning fossil fuels. It can be bad news for oysters, mussels and the marine food web. How bad? Scientists are hoping that ocean conditions off the California coast will help them find out.

At the Hog Island Oyster Company, near Point Reyes, Terry Sawyer orders oysters from hatcheries in Oregon and Washington when they’re small. They grow up in big mesh bags that sit out in Tomales Bay, where they get plump in the cold waters of the Pacific.

But a few years ago, Sawyer started getting calls from those suppliers. They couldn’t fill his orders.

“They would have tens of thousands of gallons of tanks that were absolutely full of larvae. They would have the entire system die or crash,” he says.

The hatcheries were filling their tanks with seawater that was becoming more acidic. Scientists say the oceans are 30% more acidic since the start of the Industrial Revolution. The more acidic the water, the harder it is for animals like oysters to develop their shells.

Sawyer is growing his own oyster larvae now so he’ll have a more predictable supply. But he says there’s no question that climate change is affecting his bottom line.

“We don’t know if we’re going to be able to survive the very real trending that is going on out there,” he says.

It’s trend that could affect the entire food web.

On a rocky point an hour drive north of Point Reyes, a team of scientists from the University of California’s Bodega Marine Lab is gathering. The rocks are covered in tightly packed, purplish mussels – what ecologist Eric Sanford calls the “foundation species” of the California coast.

“One that really defines the whole ecosystem, sort of the way corals define a coral reef,” he says.

Mussels are a key part of the food web. And so are a lot of animals with shells.

“Probably most people like the fact that we have things like whales and salmon off our coast and those organisms are likely to be impacted because their food source will be impacted,” says oceanographer Tessa Hill.

So the big question is: Will animals with shells be able to adapt to a more acidic future – where, in a hundred years, the oceans could be more than twice as acidic?

These California mussels could help answer that.

“They’re facing the most acidic water that you’d see in the ocean today,” says Hill.

Acidic water from the deep ocean rises to the surface on the West Coast in the spring and summer, when the wind is blowing. This upwelling makes the waters off California some of the most acidic in the world.

Inside their lab, Hill and Sanford show me jars full of young mussels, almost too small to see. Each jar is from a different part of the West Coast – from Oregon to Santa Barbara. They’re being grown in more acidic water to see if they’re better adapted to handle it, according to Sanford.

“So this is the issue we’re looking at is whether there might be genetic differences among different populations along the coast in their ability to cope with ocean acidification,” he says.

Steve Palumbi is a biology professor at Stanford University who is also working on the project. He looked at the genes of another shelled animal on the West Coast – sea urchins.

“We found they have lucky genes,” he says.

You can think of genes like a set of tools, Palumbi explains.

“If you happen to have bad plumbing, you will have more plumbing tools in your house.”

And there have been lots of plumbing problems on the West Coast – lots of acidic water.

“And so all these populations, urchins anyway, have had to get the tool set to deal with it,” he says.

Palumbi says in some urchins, they found around 100 genes that make them better adapted to more acidic water. That makes them more likely to survive and reproduce.

“This is good news because these organisms have the capacity to deal with more acidification,” he says. “But it’s not good news forever because all it does is give us a little breathing room. The trouble is right now, the rate at which the ocean is acidifying is way faster than it ever has before.”

Organisms will evolve, he says, but probably not fast enough to keep up. In the meantime, Palumbi and other scientists are mapping where the genetically resilient mussels and urchins are on the West Coast, so policymakers can look at protecting them.

Kimberly Ayers

Increasing ocean acidity can also affect nutrients like nitrogen.

The breadth of this study  – 18 research institutions and 21 scientists worldwide — and the examination of hundreds of studies stretching so far back into the geologic record makes this conclusion a singularly solid statement about the present trend.

“From everything we know today, it looks like the current rate of carbon dioxide (CO2) emissions” may spell the loss of “organisms we care about — coral reefs, oysters, salmon,” says Bärbel Hönisch, the study’s lead author, who I reached by phone in New York. She’s a paleo-oceanographer at Columbia University’s Lamont-Doherty Earth Observatory. The paper’s being published today in the journal Science.

The danger comes from what happens when CO2 is absorbed by the oceans: CO2 and water create carbonic acid, the stuff that makes soft drinks bubbly. It also makes the oceans more acidic. That acid can dissolve the shells of “keystone” species that are the building blocks for marine life. The world’s oceans are already twice as acidic – a pH drop from 8.2 to 8.1 — as they were at the start of the Industrial Revolution. That’s an acidification rate 10 times faster than anything found in the record over the past 300 million years, according to this new survey.

For her part in the study, USC doctoral candidate Rowan Martindale was looking at the juncture between the Triassic and Jurassic eras, 200 million years ago. It was a cataclysmic time when the earth’s continents were splitting apart, huge strings of volcanoes were erupting, atmospheric CO2 was at one of the highest levels ever and — you guessed it — hardly any evidence of limestone or coral, two things that dissolve in acidic water. It marked one of the five biggest extinction events in the planet’s history. Atmospheric carbon was increasing at the rate of one gigaton – about 2.2 trillion pounds — per year.

Today, atmospheric carbon is increasing at the rate of eight gigatonnes per year — about 17.6 trillion pounds. ‘Something weird was going on in the ocean back then,” Martindale says. “The modern ocean chemistry is changing, and nobody really knows exactly what’s going happen.”

Hönisch says the team cited hundreds of studies — the journal had to put a limit on their end list of 218 items — and looked at many more over the past year-and-a-half. “The strength is that when we compare these different events [in the geologic record], we can see the similarities. We can also see where we need more information.”

Both Honisch and Martindale will tell you the paleo record has its gaps and intriguing questions for further study — exactly how atmospheric warming interacts with ocean acidity, and key ocean sediments they’d love to sample that have disappeared back below the sea floor, for example — but their conclusion is clear: the world’s oceans are acidifying at a rate that has never been seen before.

“Maybe things are not as bad as we think, but we don’t know, says Hönisch. “[And] by the time we do, it may be too late to turn around.”

Craig Miller

Ocean Acidification topped the list of concerns for a panel of marine scientists opening the annual Society of Environmental Journalists conference in Miami this week.

The topic was oceans, and when moderator Nancy Baron of the science education group, COMPASS asked the scientists to “Tell us how it is, really,” panelist and top NOAA administrator Jane Lubchenco said that rapidly rising acidity in the ocean is a “huge challenge.”

“It’s the most important under-reported global environmental story today,” she said. “The ocean has become 30% more acidic over the last century, and this massive change is likely to have serious impacts, and it’s likely to get worse.”

And where it’s playing out first, said Lubchenco, is the Pacific Northwest. Coastal Washington and Oregon, she said, are “ground zero” for ocean acidification, due to upwelling from the deep ocean and local runoff that exacerbates the already acidifying sea.

An increasingly acidic ocean, she said, is sometimes referred to as “osteoporosis of the sea” because it affects the “hard parts” of organisms, causing shells to break down, or not form at all. This is not only lethal for the organisms themselves, she said, but it also disrupts the entire food chain. Lubchenco said new research is showing that rising acidity also affects organisms’ sense of smell and impacts reproduction. “This is an unfolding story,” she said. “There’s a lot we don’t know.”

Lubchenco said more research and monitoring is needed, but that’s unlikely to happen in this tough economic climate. She recommended that action be taken at the local level to reduce runoff into the sea, particularly nitrogen pollution, and to prevent overfishing and invasive species.  But the only long-term solution, she said, is for the world to reduce carbon emissions.

For an explanation of how carbon emissions influence ocean acidification, and what that means for the world’s marine ecosystems, check out this four-minute video from NOAA.

Farallon Islands. Photo: Jan Roletto, NOAA

The north-central California coast is likely to experience rising seas, more extreme weather events and coastal erosion, increased ocean acidity, and shifting marine habitats as a result of climate change, according to a new report released today from the National Oceanic and Atmospheric Administration.

The report, “Climate Change Impacts: Gulf of the Farallones and Cordell Bank National Marine Sanctuaries,” was developed in collaboration with 16 agencies and organizations and was released today at the California Academy of Sciences in San Francisco.

“This report provides insight into how climate change will play out in our region, how the ocean environment in the Gulf of the Farallones and over Cordell Bank will change and how the organisms that live there will be impacted by it,” said the report’s lead author, oceanographer John Largier of the Bodega Marine Laboratory and UC Davis.

Largier was careful to explain that the report does not make predictions about the future, nor is it a complete assessment of current conditions.

“It’s a group of scientists getting together and making their best judgment of how things are changing, how things will change, and what are we most concerned about,” said Largier.

Topping the list of concerns, he said, are rising sea levels of approximately 1.5 meters by 2100, warming oceans, an increase in the variability of precipitation (drier dry years and wetter wet ones), and ocean acidification, which he called, “the other CO2 problem,” and stressed as both a global and regional concern.

“There are a lot of things we know that are happening.  The real question we have to figure out now is how much this could all this change the ecosystem,” said Largier.  “The system is so complex, it’s not totally clear how it’s going to evolve.  Some populations might do a lot better with climate change, and others are going to be hammered. ”

Image: NOAA

The report makes some recommendations for the sanctuaries, including a greater focus on public education, implementing policies that allow for flexibility and adaptation to change, and mitigating other factors that impact the ecosystem such as pollution, invasive species, fishing, and infrastructure development.

“We are just now getting to the state where we say what does climate change mean for us, for my community?” said Largier.  “It’s warming, sure, but what does it mean for ‘here’?  How is it going to play out? And what are the things that are going to happen that really matter at a regional and local level?  This is a huge scientific challenge that we are struggling with, but it’s an essential management and policy challenge.”

Bill Douros, the West Coast Regional Director of NOAA’s Marine Sanctuary program expressed the same sentiment in his opening remarks at the Cal Academy today.

“As we all know, the ocean is going to warm, it’s going to get more acidic, sea levels are going to rise, and those concepts are important, but what’s really important to someone who might be managing those marine protected areas is “How much?” and “By when are the sea levels going to rise and temp going to increase?”  And that’s what this report today provides to us.”

Key Issues highlighted in the report:
⇒ Observed increase in sea level (100-year record at mouth of San Francisco Bay)

⇒ Expected increase in coastal erosion associated with changes in sea level and storm waves

⇒ Observed decrease in spring runoff of freshwater through San Francisco Bay (decreased Sierra snowpack)

⇒ Observed increase in precipitation variability (drier dry years, wetter wet years)

⇒ Observed increase in surface ocean temperature off the continental shelf
(50 year record)

⇒ Observed increase in winds driving coastal upwelling of nutrient-rich waters and
associated observed decrease in surface ocean temperature over the continental
shelf (30 year record)

⇒ Observed increase in extreme weather events (winds, waves, storms)

⇒ Expected decrease in seawater pH, due to uptake of CO2 by the ocean

⇒ Observed northward shift of key species (including Humboldt squid, volcano
barnacle, gray whales, bottlenose dolphins)

⇒ Possible shift in dominant phytoplankton (from diatom to dinoflagellate blooms)

⇒ Potential for effects of climate change to be compounded by parallel
environmental changes associated with local human activities