Acid In The Oceans: A Growing Threat To Sea Life Carbon dioxide isn't just affecting our climate, it is also increasing the acidity of our seas. Scientists worry that corrosive conditions will harm marine life, and could change our oceans in ways they're just now starting to understand.
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Acid In The Oceans: A Growing Threat To Sea Life

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Acid In The Oceans: A Growing Threat To Sea Life

Acid In The Oceans: A Growing Threat To Sea Life

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  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
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From NPR News, this is ALL THINGS CONSIDERED. I'm Melissa Block.


And I'm Madeleine Brand.

When we burn fossil fuels, we're not just putting carbon dioxide into the air; a lot of it goes into the sea. And there, carbon dioxide turns into carbonic acid.

BLOCK: As a result, the oceans are becoming more corrosive. Biologists say that's bad for corals, oysters, and other shell-building animals. And scientists are just starting to realize that ocean acidification could affect many other forms of sea life, as well.

To wrap up our series, Oceans at Risk, NPR's Richard Harris has this report from California's Monterey Bay.

(Soundbite of sea lions)

RICHARD HARRIS: It's comical to watch 600 pounds sea lions in the harbor at Moss Landing, California. They jostle, spar, and try to cram themselves onto to docks that can barely hold their weight.

Mr. ERIC PANE (Marine Biologist, Monterey Bay Aquarium Research Institute): It must be pup season because there's numerous youngsters out there, you can see.

HARRIS: Eric Pane looks on approvingly at what seems to be part of a Pacific success story. Up and down the coast, biologists see healthy populations of marine mammals, fish and other wildlife. But as we head into his laboratory at the Monterey Bay Aquarium Research Institute, Pane's outlook about the future of life in the sea takes a dark turn.

His budding career as a marine biologist is framed by an ominous trend: civilization is venting carbon dioxide from our tailpipes, smokestacks and chimneys at a prodigious rate.

Mr. PANE: And that CO2, at least a third of it so far has actually ended up in our oceans, so which is sort of good and bad news in that it's prevented more CO2 from accumulating in the atmosphere. But unfortunately, it comes at a price, and that CO2 going into the ocean leads to it being acidified.

HARRIS: Acidity is measured on the pH scale. Already, the oceans are a tenth of a unit more acidic. And by the end of this century, pH will change by half a unit. But don't be fooled by these modest-sounding numbers.

Mr. PANE: So we say, oh, only half a unit. What's the big deal about that, you know? That's a tripling of acidity. I mean, that's a threefold increase.

HARRIS: Over the past half-dozen years, marine biologists studying ocean acidification have focused mostly on the animals they assume will be the most vulnerable, such as coral reefs and shellfish. If acid levels in the ocean get too high, their shells can literally dissolve.

Eric Pane is part of a second wave of research on ocean acidification - that is, biologists trying to understand the consequences for all the life in the sea.

Mr. PANE: Right now, we're scrambling and we're trying to get our feet beneath us, and we're trying to basically address the simplest issue to figure what is organism response, also deal with simple ecosystem responses.

HARRIS: So do you have critters growing in your lab? Can you…

Mr. PANE: We do. We do. We're trying to, at this point, basically get as many animals as we can across a spectrum of invertebrates, vertebrates. All we can get to, basically, get them in the laboratory and expose them to these different scenarios of CO2.

HARRIS: His lab is focusing on animals that live in relatively deep water. That makes sense because they live surprisingly nearby. There's an enormous underwater canyon just offshore, slicing through Monterey Bay.

Mr. PANE: We've got gastropods, marine snails. We've had brachiopods. We've worked with decapod crabs, basic crustacea, hoping to get some smaller fish in down in our seawater lab facility.

HARRIS: Eric Pane leads us over to a lab bench. Three-inch-long marine snails sit in a glass dish.

Mr. PANE: So these are neptunium that we drilled a hole through the top of the shell, basically, so we can repetitively stick a needle through that hole and draw a sample of blood out.

HARRIS: And where did this critter come from?

Mr. PANE: These guys came from 700 meters right in the bottom of the canyon, right offshore in the Monterey Canyon.

HARRIS: Each animal they want to study presents different challenges, whether it's getting a blood sample from a snail or figuring out how to keep deep sea fish alive in the lab. It's also not always so obvious what effects to look for. A change in acid can actually impose a subtle energy tax on marine animals. They already use some energy pumping acid out of their cells to maintain a healthy pH.

As the oceans get more acidic, Pane says they'll expend more energy to maintain that balance.

Mr. PANE: You're going to have less energy available for the important things: growing, reproducing. We're going to be looking at fecundity, amount of offspring produced, health of offspring produced, and then try to extrapolate into a long-term approach what that's going to do to these ecosystems that we know.

HARRIS: It's too early to say just yet what this portends for life at sea, up to and including the fat and happy sea lions down on the dock.

Mr. PANE: I think the least we can say is there's going to be profound changes in ocean ecosystems. From there, where we go and the judgments we make about that, you know, perhaps is an issue for further on. But…

HARRIS: People think marine biology sounds really exciting. Your career almost sounds depressing.

Mr. PANE: In a way, in way. I mean, within a few years, there's going to be change, basically, and I'm not sure how it's going to work out. Now you're depressing me.

HARRIS: There are just a few people in the world who have actually been thinking about ocean acidification for decades. And one of those is down the hall from Eric Pane. Peter Brewer realized that something was amiss with the ocean's chemistry back in the 1960s, and he's seen the problem grow much, much worse.

Dr. PETER BREWER (Senior Scientist, Monterey Bay Aquarium Research Institute): The quantity of carbon dioxide we've put in the ocean is now well over 500 billion tons. And you can't just transfer that much mass without making changes in the physical properties, as well as the biological properties.

HARRIS: Brewer says the carbon dioxide has already altered ocean chemistry in such a way that it affects the way sound travels through the ocean. That effect will grow, as more and more carbon dioxide ends up in the sea.

Dr. BREWER: Sound will travel farther and noise levels will rise. That's a strange result of ocean acidification.

HARRIS: What consequences does that have?

Dr. BREWER: Nobody is that sure. It will be about, say, a 40 percent change by the middle of the century from the pre-Industrial signal. One assumes that whales, which communicate at these frequencies, will sense this effect. Whether they will adapt their communication patterns, one does not know.

HARRIS: Scientists may simply have to wait and watch to see how that unintentional experiment evolves. But Brewer doesn't have to wait to see what rising acid levels will do to ecosystems at the bottom of the sea.

Unidentified Man #1: Hi, Peter.

Dr. BREWER: This is an apparatus we're going to put on the sea floor.

HARRIS: The scientific instrument that's under construction has a green metal frame, bigger than a car with Plexiglas wings that can unfurl under water. One of the technicians is sitting right in the middle of the machine, where a test chamber will be.

Dr. BREWER: We're trying to get the cameras in?

Unidentified Man #1: Yeah.

Unidentified Man #2: The cameras and the strobe for imaging the sea floor area.

Dr. BREWER: And then we fly down and we can put some animals in there, add some carbon dioxide. It will flow through the chamber. We can create a change, and we can observe behavior, make measurements.

HARRIS: Studying animals on the sea floor would, after all, be a more realistic experiment than a lab study, presuming they can get the instrument to do a good job of simulating future ocean conditions. It'll probably take another year to sort out the technical challenges of getting this instrument to work well. And while those problems seem solvable, Brewer ponders the enormous societal problems that created ocean acidity in the first place.

Dr. BREWER: We're all in a bind here. You know, there - it's going to be very hard to maintain this number of people on the planet and not have these problems. It worries me that scientists sound the alarm but don't come up with solutions. Yeah, we're going to have to try.

HARRIS: Technology has revolutionized ocean science during Brewer's career. He can only hope that it will also revolutionize the way we produce energy before the oceans suffer irreparable harm.

Richard Harris, NPR News.

BLOCK: And you can hear Richard's other stories from our series, Oceans at Risk, at our newly redesigned Web site,

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