The Water's Edge
|Maike Nicolai||November 17th 2013|
Helmholtz-Zentrum Ozeanforschung Kiel
Exposed to simulated ocean acidification, the larvae work hard to maintain the high stomach pH values. â€œThe energetic demands to maintain the stomach pH increaseâ€™, says Dr. Marian Hu, co-first author of the study. Using antibody staining techniques, Hu discovered a high concentration of pH regulatory cells that cover the inner surface of the stomach. Such cells typically consume a lot of energy. Culturing experiments and feeding trials revealed that in order to compensate for the decreased efficiency of digestion, the larvae feed more.
â€œWhile earlier studies mainly focused on understanding calcification under acidified conditions, other vital processes, such as digestion and gastric pH regulation, were neglectedâ€, says Meike Stumpp. â€œWe can now demonstrate that they deserve much more attention.â€ â€œAll living processes are run or controlled by enzymes. They are the key in understanding the functions and reactions of organisms, and finally ecosystems, in a changing worldâ€, AWI-scientist Dr. Reinhard Saborowski adds.
â€œIf the organisms are unable to compensate for extra costs caused by ocean acidification, by eating more, they suffer negative consequences in the form of reduced growth and fertility and in extreme cases deathâ€, Dr. Sam Dupont points out. The researcher from the University of Gothenburg is senior author of the study.
The researchers in Germany and Sweden have spent several years developing their techniques. â€œStudying digestion in larvae is not easy since they are only about a fifth of a millimeter in lengthâ€, Dupont admits. â€žBut now we are able to analyze this important process and get an impression of how sea urchin larvae might react to future living conditions.â€œ