Photo gallery: Crabs

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.

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

Freshly caught snow crab jam a crab trap aboard the Arctic Hunter in the Bering Sea. Crab are emptied from the 800-pound cages, sorted and then stored in a hold below deck.

Deckhand Mizrain Rodriguez empties a cage full of snow crab onto a sorting table aboard the Arctic Hunter. Ocean acidification’s threat to red king crab has also raised concerns about the long-term fate of snow crab.

A 20-mile-long mass of sea ice drifts over the Bering Sea fishing grounds, covering buoys that mark the location of crab traps. Ice can seize the buoys and drag crab pots for miles, making it difficult for fishermen to find their gear.

A baby snow crab found in a crab pot. Scientists have struggled to keep young snow crab alive in laboratories long enough to study the direct impact of ocean acidification.

In subzero weather, Le Nguyen throws a hook line out to snare a buoy so the Arctic Hunter can haul up a crab trap.

Crewmen wait for waves to stop crashing across the shelter deck of the Arctic Hunter before lowering a crab trap back into the Bering Sea. Crab traps are dropped to the bottom of the sea one after another in a line that can stretch for miles.

Brett Robinson, captain of the Arctic Hunter, plots a course at night through the Bering Sea.

Before the first crab traps can be brought aboard the Arctic Hunter, all the deckhands, including Mizrain Rodriguez, use giant rubber mallets to smash and remove ice from the deck rails.

Brett Robinson, captain of the Arctic Hunter, is silhouetted in the wheelhouse as sea spray freezes on the boat’s windows.

Crew members aboard the crab boat Arctic Hunter are nailed with spray flying over the bow as they maneuver crab pots in the stormy Bering Sea.

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.

The crew of the Arctic Hunter takes a much-needed coffee break as the captain pilots the boat to a new location in the Bering Sea where more crab traps are ready to be pulled.

The crab-fishing boat Trailblazer pushes its way through the ice at dusk on the Bering Sea.

A crew member aboard the Arctic Hunter beats ice from the knuckle boom before using it to pull crab pots aboard. Frozen spray from a stormy night at sea had buried the empty pots on the boat’s stern in thick layers of ice.

Captain Brett Robinson turns the heat up in the wheelhouse of the Arctic Hunter to melt frozen sea spray that coated the windows. The temperature outside had dropped to about 20 degrees below.

Ice is the enemy of crab fishermen. A crewman aboard the Arctic Hunter watches as a trap rises from the frozen surface of the Bering Sea.

Chief Engineer Dave Fisher, left, prepares to swing a coil of rope into a crab trap before the trap is hoisted and stacked onto the stern of the Arctic Hunter.

Deckhand Minh Vu stands atop a slippery row of frozen crab pots, waiting to help guide another cage into place.

Deckhand Minh Vu lashes row after row of crab traps together so the 800-pound cages don’t slide into the sea as rough weather pitches the boat from side to side.

The Arctic Hunter returns to Dutch Harbor, Alaska, with a hold full of snow crab.

Crewmen aboard the Arctic Hunter sort through freshly caught snow crab on the Bering Sea.

Below deck on the Arctic Hunter, workers from Westward Seafood unload snow crab at the dock in Dutch Harbor, Alaska. While scientists have struggled to study the direct effects of ocean acidification on snow crab, related research on other crab species suggests they, too, might be susceptible.

An exhausted Westward Seafoods worker takes a break from unloading snow crab from the hold of the Arctic Hunter in Dutch Harbor, Alaska.