Tag Archives: geomar

New Challenges for Ocean Acidification Research

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SpaceDaily.com January 2nd, 2015
Kiel, Germany

To continue its striking development, ocean acidification research needs to bridge ocean acidification between its diverging branches towards an integrated assessment. This is the conclusion drawn by Prof. Ulf Riebesell from GEOMAR Helmholtz Centre for Ocean Research Kiel and Dr. Jean-Pierre Gattuso from the French Centre National de la Recherche Scientifique (CNRS) and Universite Pierre et Marie Curie.

In a commentary in the journal “Nature Climate Change”, the two internationally renowned experts reflect on the lessons learned from ocean acidification research and highlight future challenges.

Over the past decade, ocean acidification has received growing recognition not only in the scientific area. Decision-makers, stakeholders, and the general public are becoming increasingly aware of “the other carbon dioxide problem”. It is time to reflect on the successes and deficiencies of ocean acidification research and to take a look forward at the challenges the fastest growing field of marine science is facing.

In the January issue of the journal “Nature Climate Change” Ulf Riebesell, professor for Biological Oceanography at GEOMAR Helmholtz Centre for Ocean Research Kiel, and Jean-Pierre Gattuso from the French Centre National de la Recherche Scientifique (CNRS) urge the international scientific community to undertake a concerted interdisciplinary effort.

According to the two experts, future ocean acidification research will have to deal with three major challenges: It needs to expand from single to multiple drivers, from single species to communities and ecosystems, and from evaluating acclimation to understanding adaptation. “The growing knowledge in each of the diverging research branches needs to be assimilated into an integrated assessment”, Prof. Riebesell points out.

For the scientific community, it is obvious that ocean acidification does not occur in isolation. Rising temperatures, loss of oxygen, eutrophication, pollution and other drivers happen simultaneously and interact to influence the development of marine organisms and communities.

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How Will Cod React to Global Warming? Researchers Subject Fish to High CO2 Levels to Find Out

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May 8th, 2014, By Eva Tallaksen, undercurrentnews.com

cod in high co2Scientists in Tromso, Norway, are exposing cod broodstock to high CO2 to find out how the fish will cope as the seas get warmer, and more acidic.

“The idea is to find out, how will ocean acidification affect aquaculture and wild fish?” said Christopher Bridges, zoology professor at the university of Dusseldorf.

It is hoped larvae scooped from five tanks at Nofima’s national cod breeding center will soon yield some clues.

Each tank contained 60 cod broodstock averaging 3-5 kilos in size, exposed to different levels of temperatures and acidity. The fish spawned March and April, and their larvae, which hatched in the past two weeks, are currently being tested.

“The key aspect will be to look at the larvae’s survival rate,” said Bridges.

If global warming continues as some scientists think, the oceans’ CO2 levels could reach 1,000 to 1,200 ppm (parts per million) by 2100, up from just under 400ppm today.

That would take the seas’ pH level down to 7.8, from 8.1 today.

Most the research into the seas’ growing acidity has focused on the impact on fish eggs or larvae, or on habitats. But few have so far focused on its impact on broodstock, said Bridges.

Bridges is one of the scientists involved in the project, which is led by the publicly-funded German Bioacid initiative. Cooperating in the project are Germany’s Geomar and Alfred Wegner Institute, working in Norway under the EU FP7 support project Aquaexcel using the facilities of Nofima.

In two of the tanks, the cod were kept at normal acidity levels (400ppm), but one tank had a temperature of 5 degrees Celcius, and the other 10 degrees. In two other tanks, the fish were exposed to CO2 levels of 1,200 ppm, again with one tank at 5 degrees and the other at 10 degrees.

These four tanks all used broodstock from farmed fish, bred by Nofima’s center. A fifth tank was filled with fish from the wild, but these were caught too late to be used for the experiment.

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