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The Baltic Sea shows the way for the oceans

Published: 9 May 2018

Warming, acidification, eutrophication and the loss of oxygen are just a few examples of major changes being observed or expected for oceans around the world. The Baltic sea provides useful lessons for how negative trends can be reversed by protective measures, according to an international team of researchers, including from Luleå University of Technology.

In the current issue of the international journal Science Advances, 26 authors from seven countries appeal to the greater scientific community and policy makers to use the Baltic Sea Region as a model for coming changes in the world's oceans.

The scientists, including Luleå University of Technology’s Professor Annica Sandström, argue that changes that are only expected for the future in the global ocean can already be observed in the Baltic today.

Overfishing, warming, acidification, pollution, eutrophication, loss of oxygen, intensive use of coasts—all these are phenomena that we observe around the globe. 

– The Baltic region can be seen as a model for what can be expected and what could be done elsewhere. The changes have been extra dramatic in the Baltic Sea, but some of the problems have also been successfully resolved, says Annica Sandström, Professor of Political Science at Luleå University of Technology and one of the authors behind the study.

Large oxygen-free zones

The oceans have warmed by an average of 0.5°C over the past 30 years, while in the same period, time-series measurements in the Baltic Sea have recorded warming of around 1.5°C. Likewise, there are large oxygen-free zones in the deep areas of the Baltic Sea, which have increased tenfold over the past century; and the pH – a measure of ocean acidification – of Baltic waters regularly reaches values that are expected in other ocean areas only in the next century.
– Likewise, we can observe acidification in the Baltic Sea through the lower pH values, which regularly drop to levels expected in the major oceans only in the next century, says Kerstin Johannesson, Professor and marine scientist at the University of Gothenburg.

Nine countries border the Baltic Sea – all of them highly industrialized, with densely populated coastal regions. Moreover, intensive agriculture in the interior ensures high nutrient runoff, while equally intensive fisheries puts pressure on the pelagic food-web. 

Strong tradition of cooperation

But it’s not all doom and gloom. The Baltic Sea is one of the best-surveyed seas on Earth. Scientific observation and monitoring of physical and biological processes began around 1900. There is a strong tradition in scientific co-operation among many countries surrounding the Baltic, culminating in the implementation of the joint Baltic Sea research and development programme BONUS of the European Union, a dedicated macro-regional research agenda and funding scheme that also enabled the present study. These data provide a sound basis for science-based resource management.

Among the management success stories: the bordering countries have managed to significantly reduce nutrient inputs since the 1980s, to reverse the decline of large predators, and to curb overfishing. This has been achieved through the binding agreements within the framework of the European Union, but also thanks to the ambitious goals of the Baltic Sea Action Plan (BSAP), which included Russia, even before the end of the Cold War. 

Annica Sandström

Annica Sandström, Professor

Phone: +46 (0)920 491356
Organisation: Political Science, Social Sciences, Department of Social Sciences, Technology and Arts