Climate change puts coastal crabs in survival mode, study finds

November 12, 2014, San Francisco State University

Porcelain crabs can adapt to a warming climate but will not have energy for much else beyond basic survival, according to new research published today from San Francisco State University.

The findings have grim long-term implications for intertidal zone as well as the myriad species that depend on them, and could be an indicator of how other intertidal organisms may respond to a rapidly changing climate.

The study is detailed in an article published in the Journal of Experimental Biology and is the first to explore intertidal zone organisms' response to combined variation in temperature and pH, which is expected to intensify in the future due to and .

"Previous research had looked at constant levels of temperature and pH, but those are really unnatural conditions in the highly variable intertidal zone," said Jonathon Stillman, a professor of biology at SF State and co-author of the study.

"We wanted to look at variability in those two factors and see how the crabs would respond to climate change and ocean acidification."

To do so, Stillman and his fellow researchers—master's student Adam Paganini and post-doctoral scholar Nathan Miller—placed the crabs in a specially built aquarium designed to simulate the natural environment, including tidal changes. At low tide, with the crabs exposed to the air, the researchers varied the temperature to mirror day-to-day changes the crabs currently experience—such as cooler air on a cloudy day and warmer air on a sunny day—as well as conditions expected in the future. At high tide, with the crabs submerged, they adjusted pH levels in the same fashion.

As the temperature rose and pH levels dropped—conditions expected in the future due to climate change—the crabs' ability to withstand heat increased. But at the same time, researchers found, the crabs' metabolism decreased. In addition, the combined effect of higher temperatures and lower pH levels was greater than the effect of either of those two factors alone.

"When you combine these things together, they slow down metabolism, which means crabs become sluggish and have less overall energy to do things like growth or reproduction," Stillman said. "If their whole energy budget is a pie, then in the future the size of the pie is going to be smaller, and a larger percentage of it is going to be taken up by survival and maintenance."

Although porcelain crabs are not particularly important to humans—they are not fishery crabs such as Dungeness—they are an important food source for coastal fish, birds and other crabs. They can also be seen as a model for scientists to understand the impacts of climate change and ocean acidification on crustaceans in general, according to Stillman. Future studies will look at the impact of varying temperature and pH changes on different species of porcelain crabs, juvenile crabs and crab embryos.

Explore further: Acidifying oceans may be harmful to porcelain crabs

More information: "Temperature and acidification variability reduce physiological performance in the intertidal zone porcelain crab Petrolisthes cinctipes," by Adam W. Paganini, Nathan A. Miller and Jonathon H. Stillman, was published Nov. 12 in the Journal of Experimental Biology.

Related Stories

Acidifying oceans may be harmful to porcelain crabs

April 8, 2013

(Phys.org) —As the world's oceans soak up carbon dioxide from an atmosphere increasingly polluted by fossil fuels, seawater will become more acidic. Two new studies by San Francisco State University students suggest marine ...

Ship noise makes crabs get crabby

February 26, 2013

A study published today in Biology Letters found that ship noise affects crab metabolism, with largest crabs faring worst, and found little evidence that crabs acclimatise to noise over time.

Recommended for you

Pigs form a visual concept of human faces

August 17, 2018

Contrary to previous studies, pigs appear to have better visual discrimination abilities than had previously been assumed. Cognition researchers from the Messerli Research Institute showed in a new study that pigs not only ...

Are our wild animals growing old gracefully?

August 17, 2018

For most of us, the body's deterioration is an unavoidable part of getting older. This age-related decline, known as "senescence", can occur subtly and slowly for some individuals, while for others it happens much faster. ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

antigoracle
1 / 5 (1) Nov 12, 2014
Oh nose!!! Not da crabs, not da crabs.
First it was the Polar bears, then the corals, followed by the frogs, birds and bees.
Oh what next? What lie would the AGW Cult dream up when they go to sleep in their CO2 filled rooms?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.