Navigation Links
Ocean acidification: Hard to digest

15.11.2013/Gteborg, Kiel, Bremerhaven. Ocean acidification impairs digestion in marine organisms, according to a new study published in the journal Nature Climate Change. Researchers from Sweden and Germany have studied the larval stage of green sea urchins Strongylocentrotus droebachiensis. The results show that the animals have problems digesting food in acidified water.

Carbon dioxide (CO2) emissions do not only affect the climate but also our seas and oceans. One-quarter of all CO2 released into the atmosphere is absorbed by the oceans. Once there, the CO2 is converted to carbonic acid, making the water more acidic. Previous studies showed that marine species and ecosystems can suffer in an acidified environment. Although the reason for the sensitivity was seen in physiological processes, mechanisms remained unclear. Scientists from the universities of Gothenburg (GU) and Kiel (CAU), as well as GEOMAR Helmholtz Centre for Ocean Research Kiel and Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) found that ocean acidification leads to reduced rates of digestion in larvae of the ecologically important green sea urchin Strongylocentrotus droebachiensis. The findings are published in the international journal Nature Climate Change.

Dr. Meike Stumpp, former PhD student at GEOMAR and Kiel University and first author of the study, used novel pH micro-electrode techniques and designed new assay methods during her postdoc at the University of Gothenburg to investigate digestion and digestive enzymes in the larvae. She showed that when larvae are exposed to acidified seawater, the digestion takes longer and is less effective. "My measurements demonstrated a very strong pH dependency", Stumpp explains. "The enzymes in the sea urchins' stomachs are optimized to function at very high pH which is different from the situation in mammals, where stomach pH is acidic and enzymes work best at low pH."

Exposed to simulated ocean acidification, the larvae work hard to maintain the high stomach pH values. "The energetic demands to maintain the stomach pH increase', 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.

"While earlier studies mainly focused on understanding calcification under acidified conditions, other vital processes, such as digestion and gastric pH regulation, were neglected", says Meike Stumpp. "We can now demonstrate that they deserve much more attention." "All 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 world", AWI-scientist Dr. Reinhard Saborowski adds.

"If 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 death", 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. "Studying digestion in larvae is not easy since they are only about a fifth of a millimeter in length", Dupont admits. But now we are able to analyze this important process and get an impression of how sea urchin larvae might react to future living conditions."


Contact: Maike Nicolai
Helmholtz Centre for Ocean Research Kiel (GEOMAR)

Related biology news :

1. New generation of micro sensors for monitoring ocean acidification
2. Tracking young salmons first moves in the ocean
3. UH among Texas institutions that will lead Ocean Energy Safety Institute
4. Maintaining strength in ocean science requires greater collaboration, coordination, and integration
5. VC predicts the motion of the ocean
6. UCLA report urges new global policy effort to tackle crisis of plastic litter in oceans
7. Redwood trees reveal history of West Coast rain, fog, ocean conditions
8. Researchers quantify toxic ocean conditions during major extinction 93.9 million years ago
9. Study maps human impacts on top ocean predators along US west coast
10. Coral chemicals protect against warming oceans
11. NSF awards grants for deployment of new observing system in the North Atlantic Ocean
Post Your Comments:
Related Image:
Ocean acidification: Hard to digest
(Date:6/22/2016)... American College of Medical Genetics and Genomics was once again ... of the fastest-growing trade shows during the Fastest 50 Awards ... Las Vegas . Winners are ... of the following categories: net square feet of paid exhibit ... 2015 ACMG Annual Meeting was ranked 23 out of 50 ...
(Date:6/16/2016)... The global Biometric ... USD 1.83 billion by 2024, according to a ... proliferation and increasing demand in commercial buildings, consumer ... the market growth.      (Logo: ... of advanced multimodal techniques for biometric authentication and ...
(Date:6/3/2016)... , June 3, 2016 ... von Nepal hat ... Lieferung hochsicherer geprägter Kennzeichen, einschließlich Personalisierung, Registrierung ... in der Produktion und Implementierung von Identitätsmanagementlösungen. ... Ausschreibung im Januar teilgenommen, aber Decatur wurde ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... SPRING, Md. , June 23, 2016 A ... collected from the crime scene to track the criminal down. ... and the U.S. Food and Drug Administration (FDA) uses DNA ... Sound far-fetched? It,s not. The ... genome sequencing to support investigations of foodborne illnesses. Put as ...
(Date:6/23/2016)...  The Biodesign Challenge (BDC), a university competition that ... living systems and biotechnology, announced its winning teams at ... New York City . The teams, ... at MoMA,s Celeste Bartos Theater during the daylong summit. ... curator of architecture and design, and Suzanne Lee ...
(Date:6/23/2016)... , ... June 23, 2016 , ... In a new ... in Denmark detail how a patient who developed lymphedema after being treated for breast ... results could change the paradigm for dealing with this debilitating, frequent side effect of ...
(Date:6/23/2016)... On Wednesday, June 22, 2016, the NASDAQ Composite ... Jones Industrial Average edged 0.27% lower to finish at 17,780.83; ... has initiated coverage on the following equities: Infinity Pharmaceuticals Inc. ... NKTR ), Aralez Pharmaceuticals Inc. (NASDAQ: ARLZ ), ... more about these stocks by accessing their free trade alerts ...
Breaking Biology Technology: