Photo gallery: Overview

Katharina Fabricius swims through carbon-dioxide bubbles off Papua New Guinea. The waters here offer a glimpse of how acidification is likely to transform the seas.

Colorful baby corals and coralline algae sprout on a ceramic tile, at left, placed near healthy coral in Papua New Guinea as part of a scientific experiment. On the tile at right, placed near carbon-dioxide vents in Papua New Guinea, algae and seaweed crowd out reef growth. The water chemistry there mirrors what scientists believe the oceans will be like in 60 to 80 years.

Unhealthy reef: Fabricius records data from instruments placed alongside corals in the CO₂ vents off Dobu Island.

Healthy reef: Fish swim around branching corals amid a pristine reef near Dobu Island, Papua New Guinea.

Clownfish swim through an anemone near Dobu Island, Papua New Guinea. CO₂ can alter how clownfish see, hear and smell, which increases the chance of death.

Biologists Sam Noonan, left, and Miwa Takahashi collect sea grass in Papua New Guinea. Sea grasses, which are expected to increase as the ocean becomes more acidic, grow far faster near the CO₂ vents.

Crew members aboard the Arctic Hunter lower a crab pot into the Bering Sea.

Young red king crab are being raised in a shellfish hatchery in Seward, Alaska, as part of an experimental effort to provide options for troubled wild populations.

Graduate student Asia Beder holds a mature red king crab pulled from a tank at the Alutiiq Pride Shellfish Hatchery in Seward, Alaska. New research suggests ocean acidification poses a significant threat to Alaska’s famed red king crab industry.

Deckhands aboard the crab boat Arctic Hunter in the Bering Sea off Alaska separate male and female snow crab. Red king crab are highly susceptible to changes in water chemistry, which raises concerns about whether snow crab will be, too.

Researchers at Western Washington University are trying to find out whether ocean acidification will harm — or perhaps help — tiny copepods, which play an important role at the bottom of the marine food chain.

This pteropod, also known as a sea butterfly, comes from Puget Sound. The tiny shelled creatures are an important food source for many fish and seabirds. The shells of pteropods already are eroding in Antarctica, where the water chemistry isn’t as bad as it is in parts of the Pacific Northwest.

Walleye pollock swim in a tank at a research lab in Oregon. Early research suggests elevated CO₂ can alter pollock behavior much as it alters the behavior of some tropical reef fish.

Workers slice Pacific cod into fillets at a processing plant in Dutch Harbor, Alaska. Cod is the second-largest groundfish fishery in Alaska, behind only pollock.

A worker strains tens of thousands of tiny young oysters through a sieve at a hatchery in Hawaii owned by Washington’s Goose Point Oyster Co.

Oysters from the Nisbets’ Hawaii hatchery are almost ready to be shipped to Willapa Bay and planted. When corrosive water off Washington rises to the surface, many oysters die before reaching this age.

A worker harvests oysters from the Nisbet family’s Goose Point Oyster Co. in Willapa Bay. After ocean acidification started killing billions of baby oysters along Washington’s coast, both in the wild and in hatcheries where the Nisbets bought their oyster seed, the family took a radical step. They opened a hatchery in Hawaii.

Ed Jones, manager at the Taylor Shellfish Hatchery in Hood Canal’s Dabob Bay, pries open an oyster. Ocean acidification is believed to have killed billions of oysters in Northwest waters since 2005.