Ocean acidification could cause loss of biodiversity in Barents Sea
The Barents Sea is particularly vulnerable to lowering pH levels and increasing acidification, say some scientists. Its cold water temperatures allow it to absorb greater amounts of CO2 than warm waters, meaning, the Barents Sea could acidify quicker than other water systems in the world, threatening biodiversity.
As a group of British scientists return from the North Pole with new data concerning the acidification of Arctic sea water, Nordic scientists at home are especially concerned about the direct effects on the Barents Sea.
Researchers with the Catlin Arctic Survey ventured north to collect the first ever water samples from the pole in order to study the rate of ocean acidification caused by rising CO2 levels. Cold waters absorb greater amounts of CO2 than warm waters, which consequently lowers the pH level and increases acidification.
The Barents Sea is particularly vulnerable because it holds some of the largest fish stocks in the world, and since its waters have low temperatures, it can absorb higher amounts of CO2. Moreover, unlike the North Pole, the Barents Sea doesn’t have ice caps to serve as a natural barrier from the airborne gas and help reduce the rate of acidification.
- We have seen the most vigourous change in the Nordic Seas, said Richard Bellerby of the Bjerknes Centre for Climate Change in an interview with the Barents Observer.
In the last 150 years the pH level of Earth’s oceans has dropped 0.1 on the logarithmic pH scale. However, if the current rate of CO2 emissions continues, the Barents Sea will see a drop of 0.35 in the next 60 years, said Bellerby.
The threats of ocean acidification on the Barents Sea as well as on the planet are great, say some scientists.
- Lower pH levels make it difficult for species that produce calcium-carbonate shells, said Jan Helge Fosså from the Norwegian Institute for Marine Research.
Shellfish, including clams and microorganisms like pteropods, will have trouble creating viable shells in increasingly acidic water and could experience slower growth rates, he said.
According to Bellerby, pteropods and other planktonic calcifiers will experience adverse affects from ocean acidification. This is dangerous since they’re important links in the Arctic food chain, which include herring, cod and mackerel.
- It’s biodiversity which is the question; the threat to biodiversity with loss of key species in the Barents Sea, said Bellerby.
In 2008, a study was conducted by scientists from universities including Pierre and Marie Curie University and Laboratoire d’Océanographie de Villefranche which collected a sample of 50 pteropods from Kongsfjorden, Svalbard.
They subjected the pteropods to projected levels of ocean acidification for 2100, which they say is a 28 per cent decrease in pH levels. The study found that after five days all pteropods were alive, but only 30 per cent were active swimmers.
It was the first study to provide both qualitative and quantitative evidence that increased ocean acidification affects calcification rates in pteropods. It can be found in the science journal Biogeosciences.
- Ocean acidification is becoming more talked about because in the last five to ten years we’ve realized the problem. It’s come sneaking up and now it’s realized, said Fosså.
In addition to animal life, the cold water coral reefs along the Norwegian shelf and coast, including into the Barents Sea, could be affected by increasing acidification.
The long term effect is the world’s oceans will increasingly lose their ability to absorb CO2, said Bellerby.
Currently, the oceans absorb approximately 25 per cent of all CO2 emissions each year, reported the European Project on Ocean Acidification.
- Over time, the ocean will stop the luxury it has afforded to us and more of what we produce will remain in the atmosphere … it will accelerate climate change, said Bellerby.
The Norwegian Government and all Nordic countries have made note of this environmental threat.
At the 2010 Trondheim Conference on Biodiversity, hosted by the Government of Norway and the United Nations Environment Program among others, a call for ocean acidification reduction was documented. Also, Nordic ministers on the Arctic Council have requested one of their working groups, the Arctic Monitoring and Assessment Programme, to complete a study on the threats of increasing acid levels in the Arctic region.
Written by Margaret Cappa, with files from Chantaie Allick