Unique insight into climate change signals major repercussions for the Baltic Sea
The end of the 21st century could signal major repercussions for marine life in the Baltic Sea. New research has estimated that climate change will increase temperature levels and lower salt content than at any time since 1850. Researchers from countries around the Baltic Sea have been collaborating on an interdisciplinary project to study the effects of global climate change on the environment in the Baltic Sea. They are combining today's best climate models with models of additional factors that affect the environment in this region. One of the researchers is Professor Jonathan Havenhand from the Department of Biological and Environmental Sciences at the University of Gothenburg, Sweden explains: 'There are plenty of studies showing the environmental impact of individual factors, or models showing global changes in the climate, but this is the first time that anyone has taken a detailed look at how these factors combine to affect a specific region. This makes this project unique.' Researchers have studied how well the models work by entering data from 1850 until 2006, and then comparing the models' predictions with what actually happened during that period. This result provides confidence in the models' ability to predict what will happen in the Baltic Sea between now and 2098. It revealed that the salt content will fall and the sea temperature will rise as a consequence of increases in air temperature and precipitation. Researchers believe that the increase in sea temperature will cause the oxygen content of the water to fall, making the effects of eutrophication (an increase in the rate of supply of organic matter in an ecosystem) to be more pronounced. As a consequence the change in salt content may result in species that are currently at the edge of their dispersion area disappearing, leading to a decline in the diversity of species. As Professor Jonathan Havenhand explains: 'One such example is the blue mussel, which cannot survive if the salt content is lower than it is at present in the Northern Baltic Sea. It feeds on algae and purifies large volumes of water. This makes it an important species. We can also expect cod stocks to fall, even if we restrict fishing, as the oxygen content, temperature and salt content will change so much that reproduction will become difficult.' The study also revealed that despite these changes it may be possible to counteract the effects of global climate change on the environment in the Baltic Sea, for example by reducing the run-off of nutrients from land. One special feature of the study is that it quantifies the effects of such measures. Professor Jonathan Havenhand is quick to point out: 'We aren't making any judgement about what should be done, we're simply providing a tool to allow decision-makers to assess what needs to be done in order to achieve a given desired effect.' The 'desired effect' may not be happening anytime soon, however. A survey conducted among decision makers in the countries around the Baltic Sea showed that while climate change is viewed as a problem, it is perceived to be something relatively remote in terms of time. For the researchers, it means more information is needed to demonstrate the importance and urgency of measures to counteract the effects of climate change. However, there is some good news for researchers. The results of the study will contribute to the Helsinki Commission's (HELCOM) proposed action plan for the Baltic Sea.For more information, please visit:IOP Science:http://iopscience.iop.org/University of Gothenburg:http://www.gu.se/
Countries
Sweden