The finding, based on research by University of North Carolina at Chapel Hill marine scientist Justin Ries, could have important implications for ocean food webs and the multi-billion dollar global market for shellfish and crustaceans.
Previous research has shown that ocean acidification – the term for falling pH levels in the Earth’s oceans as they absorb increasing amounts of carbon dioxide (CO2) from the atmosphere – is likely to slow the growth or even dissolve the shells of such creatures.
However, the new study, published in the December issue of the journal Geology, suggests that sediment-dwelling marine organisms may exhibit a wider range of responses to CO2-induced acidification than previously thought: some may get weaker while others become stronger.
Researchers also found that creatures whose shells grew the most, such as crabs, tend to prey on those whose shells weakened the most, such as clams.
Such changes could have serious ramifications for predator and prey relationships that have evolved over hundreds of millions of years, said Ries, Ph.D., assistant professor of marine sciences in the UNC College of Arts and Sciences.
“There is no magic formula to predict how different species will respond, but one thing you can be sure of is that ecosystems as a whole will change because of these varied individual responses,” Ries said.
Researchers grew 18 different species of economically and ecologically important marine calcifiers (creatures that make their shells out of calcium carbonate) at various levels of CO2 predicted to occur over the next several centuries. When CO2 combines with water, it produces carbonic acid, raising the overall amount of carbon in seawater but reducing the amount of the carbonate ion used by organisms in their calcification.
Seven species (crabs, lobsters, shrimp, red and green calcifying algae, limpets and temperate urchins) showed a positive response, meaning they calcified at a higher rate and increased in mass under elevated CO2. Ten types of organisms (including oysters, scallops, temperate corals and tube worms) had reduced calcification under elevated CO2, with several (hard and soft clams, conchs, periwinkles, whelks and tropical urchins) seeing their shells dissolve. One species (mussels) showed no response.
“Shelled marine organisms need carbonate ions to build their shells that protect them from the intense predation that defines everyday life on the shallow sea floor,” Ries said. “The organisms that responded positively to higher CO2 levels are apparently more adept at converting the elevated dissolved inorganic carbon in the seawater, which results from elevated atmospheric CO2, back into a form that they can use directly in their calcification. The others, however, appear to be less adept at manipulating dissolved inorganic carbon.”
Ries said the varied responses may reflect differences in organisms’ ability to regulate pH levels at their sites of calcification; their ability to generate a protective organic layer that limits their exposure to surrounding seawater; whether they use more soluble forms of calcium carbonate in their shells; and their ability to utilize CO2 directly via photosynthesis.
The co-authors of the Geology study are Anne L. Cohen and Daniel C. McCorkle from Woods Hole Oceanographic Institution, Woods Hole, Mass.Images:
To see the effect of different CO2 levels on a sea urchin, go to: http://uncnews.unc.edu/images/stories/news/science/2009/pencil%20urchin_credit%20justin%20ries.jpg
Ries’ Web page: http://www.unc.edu/~jries/
Media note: Ries can be reached at (919) 536-9070 or email@example.com.
Patric Lane | Newswise Science News
Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds
25.07.2017 | University of Illinois at Urbana-Champaign
NASA flights gauge summer sea ice melt in the Arctic
25.07.2017 | NASA/Goddard Space Flight Center
Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers
Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...
Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.
At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...
3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects
A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
21.07.2017 | Event News
19.07.2017 | Event News
12.07.2017 | Event News
25.07.2017 | Physics and Astronomy
25.07.2017 | Earth Sciences
25.07.2017 | Life Sciences