Behind the scenes

Tanner crabs

tanner crabs

(top) This image was captured inside the control room of the R/V Rachel Carson. On the right side, you can see the suction sampler tucking away a tanner crab into the vehicle’s sample compartment.
(bottom) 12 tanner crabs were captured from the seafloor with the ROV Ventana.

November 18, 2013

Marine scientists want to know what the increasing levels of human-generated carbon dioxide in the ocean mean for the ocean’s ecosystems and inhabitants. Last week, Jim Barry’s research group collected 12 tanner crabs from the seafloor to get a better understanding of how ocean acidification affects the behavior of sea animals. The crabs were collected in Monterey Bay with ROV Ventana, almost 1,000 meters below the ocean’s surface. The vehicle is equipped with a suction sampler used to suck up animals and place them into a sample compartment to bring them back to the surface. What will Barry’s research group do next with the tanner crabs? They will expose the crabs to varying pH levels—the increased carbon dioxide in the ocean results in lower pH levels, meaning the water is more acidic. They will observe the crabs’ behavior as they walk on a treadmill built specifically for this study. They expect that the behavior of crabs exposed to higher acidity will deviate from that of crabs in “normal” levels of acidity.