Acidification: A chilling view of tomorrow’s oceans

Shifting sea chemistry can cripple the reefs where fish live, rewire fish brains and attack what fish eat.

THE SEATTLE TIMESSeptember 16, 2013 

US NEWS ENV-OCEANHEALTH-1 7 SE

Colorful baby corals and coralline algae sprout on a ceramic tile, left, that was placed near healthy coral in Papua New Guinea. On the tile at right, placed near carbon-dioxide vents in Papua New Guinea, algae and seaweed crowd out reef growth.

STEVE RINGMAN — MCT

NORMANBY ISLAND, Papua New Guinea — Katharina Fabricius plunged from a dive boat into the Pacific Ocean of tomorrow.

A bleak portrait emerged: Instead of tiered jungles of branching, leafy corals, Fabricius saw mud, stubby spires and squat boulder corals. Snails and clams were mostly gone, as were worms, colorful sea squirts and ornate feather stars.

Instead of a brilliant coral reef such as the one living a few hundred yards away, what the Australian Institute of Marine Sciences ecologist found resembled a slimy lake bottom.

The cause: carbon dioxide.

In this volcanic region, pure CO2 escapes naturally through cracks in the ocean floor, altering the water’s chemistry the same way rising CO2 from cars and power plants is changing the marine world.

As a result, this isolated bay offers a chilling view of the future of the seas under ocean acidification.

As the burning of coal, oil and natural gas belches carbon dioxide into the air, a quarter of it gets absorbed by the seas, changing ocean chemistry faster than at any time in human history.

To understand how that will alter the seas, The Seattle Times crisscrossed the Pacific Ocean from Papua New Guinea to Alaska, interviewed nearly 150 experts and people most likely to be affected, and reviewed most of the peer-reviewed studies.

The Times found that ocean acidification is helping push the seas toward a great unraveling that threatens to scramble marine life on a scale almost too big to fathom — and far faster than first expected.

Already, it has killed billions of oysters along the Washington coast and at nearby hatcheries. It has helped destroy mussels on some Northwest shores. It is a suspect in the softening of clam shells and in the death of some baby scallops. It already is dissolving tiny plankton, called pteropods, in Antarctica that are eaten by many ocean creatures — and that wasn’t expected for 25 years.

The problem: When carbon dioxide mixes with water, it takes on a corrosive power that erodes some animals’ shells or skeletons. It also robs the water of ingredients animals use to grow shells in the first place.

New science shows ocean acidification also can bedevil fish and the animals that eat them, from sharks to whales and seabirds.

Those changes pose risks for food supplies, from the fillets used in McDonald’s fish sandwiches to the crab legs sold at seafood markets. Both are brought to the world by a Northwest fishing industry that nets half the nation’s catch.

RAPID CHANGE

Sea chemistry changes are coming as the oceans also warm, and that’s expected to frequently amplify the impacts.

This transformation — once not expected until the end of the century — will be well underway, particularly along the West Coast, before today’s preschoolers reach middle age.

“I used to think it was kind of hard to make things in the ocean go extinct,” said James Barry, of the Monterey Bay Aquarium Research Institute in California. “But this change we’re seeing is happening so fast it’s almost instantaneous. I think it might be so important that we see large levels, high rates of extinction.”

The country isn’t doing much about it. Combined nationwide spending on acidification research for eight federal agencies, including grants to university scientists by the National Science Foundation, totals about $30 million a year. The federal government has spent more some years just studying sea lions in Alaska.

WINNERS AND LOSERS

Species’ reaction to high CO2 can vary dramatically. Acidification can kill baby abalone and some crabs, deform squid and weaken brittle stars while making it tough for corals to grow. It tends to increase sea grasses, which can be good, and boost the toxicity of red tides, which is not. It makes many creatures less resilient to heavy metal pollution.

Roughly a quarter of organisms studied by researchers in laboratories actually do better in high CO2. Another quarter seem unaffected. But entire marine systems are built around the remaining half of susceptible plants and animals.

Already, the oceans have grown 30 percent more acidic since the dawn of the industrial revolution — 15 percent since the 1990s. By the end of this century, scientists predict, seas may be 150 percent more acidic than they were in the 18th century.

One-sixth of animal protein consumed by humans comes from marine fish — in some cultures nearly all of it.

To understand the future of the marine food web, government computer modelers have been studying how sea-chemistry changes could reverberate through the ocean. Their initial results, looking at just the U.S. West Coast, are disturbing.

“Right now, for acidification in particular,” said Isaac Kaplan, a NOAA researcher in Seattle, “the risks look pretty substantial.”

Kaplan’s early work projects potentially significant declines in sharks, skates and rays, some types of flounder, rockfish and sole, and Pacific whiting, also known as hake, the most frequently caught commercial fish off the coast of Washington, Oregon and California.

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