Biological Impacts of Ocean ACIDification (BIOACID)

Summary of the project


Next to the atmosphere, the ocean is the second largest sink for anthropogenic carbon dioxide. As fossil fuel CO2 enters the surface ocean, it reacts with seawater to form bicarbonate and protons, thereby consuming carbonate ions. The net result of this process, termed ocean acidification, is an increase in CO2 and bicarbonate concentrations and a decrease in seawater pH and carbon ion concentration. If CO2 emissions continue to rise at current rates, before the end of this century the resulting changes in seawater chemistry will expose marine organisms to conditions which they have not experienced during their recent evolutionary history and which may pose a threat to the competitive fitness of pH/CO2 sensitive species and groups. Thus, as the ocean continues to acidify, there is an increasing risk of biodiversity losses, of profound ecological and functional shifts, and of a reduced capacity of the ocean to buffer further CO2 increase. Despite this emerging problem and the risks it may involve, surprising little is know about the possible impacts of ocean acidification. To close the many gaps in our understanding and to allow a systems-based assessment of the risks and uncertainties associated with ocean acidification, BIOACID will take an integrated approach combining the expertise of molecular and cell biologists, biochemists, plant and animal physiologists, marine ecologists, ocean biogeochemists and ecosystem modellers. The interaction between BIOACID scientists across disciplines, research themes and projects will include joint experiments, collaborative use of equipment and measurement capacity, exchange of samples and expertise, and the analysis and synthesis of comprehensive data sets towards an ecosystem model of ocean acidification. These activities will be complemented by training workshop offered by BIOACID experts to all members of the consortium. Following this approach, the overarching questions of BIOACID are: What are the effects of ocean acidification on marine organisms and their habitat, what are the underlying mechanisms of responses and possible adaptations on the level of populations and communities, how are they modulated by other environmental stressors, and what are the consequences for marine ecosystems, ocean biogeochemical cycles, and possible feedbacks to the climate system?

To address these questions for a wide range of potentially sensitive biological processes, research activities will be structured according to key ecosystem components and functional groups. Information gained in a variety of experimental approaches and field assays will be synthesized to obtain an integrated assessment of sensitivities and uncertainties and to identify the potential thresholds associated with ocean acidification. BIOACID will benefit from close interactions with related national and international project focussing on ocean acidification and ocean warming. 


BIOACID (Biological Impacts of Ocean Acidification), the German national project on ocean acidification, has been extended for a second 3-year phase starting on September 1st 2012. Building on the knowledge gained during phase 1, BIOACID II will aim at community level responses to ocean acidification, their ecosystem and biogeochemical consequences and socio-economic impacts.

Research will focus on five major topics:

  • Pelagic ecosystems under ocean acidification: ecological, biogeochemical, and evolutionary responses 
  • Responses of benthic assemblages to interactive stress.
  • Natural CO2-rich reefs as windows into the future: Acclimatization of marine life to long-term ocean acidification and consequences for biogeochemical cycle.
  • Effects of ocean acidification in a warming climate on species interactions at distribution boundaries: mechanisms and consequences at ecosystem level
  • Services of the ocean

Area of study

North-, Baltic-, High Arctic Seas and selected Tropical regions

TimeTable for activities

Beginning and end of project: September 1st 2009 – August 31st 2015