The Baltic Sea is one of the best-surveyed seas on Earth. Scientific survey and monitoring of physio-biological processes began around 1900. Baltic sea is surrounded by nine countries. All these countries are highly industrialized and densely populated.

Due to the human activities, the sea has witnessed drastic changes. Major changes include Warming, acidification, eutrophication and the loss of oxygen in many places in the sea. These changes are occurring in all the oceans, but it is happening at a much faster pace in the Baltic Sea.

Example: In the last 30 years, the temperature of the oceans has increased by 0.5 degrees whereas the Baltic sea’s temperature has increased by 1.5 degrees. The pH measure of Baltic waters has reached values that are expected in other ocean areas in the future.

Baltic Sea as a Model.

The scientists explain that this amount of variations in the sea are expected only in the future. But it can already be observed in the Baltic today. “This is because the small volume of water and slow water exchange with the open ocean, behaves like an amplifier, allowing many processes and interactions to occur at a faster pace,” emphasizes Dr Jan Dierking from GEOMAR, who initiated the study along with Professor Reusch. Their study was published in the science advances.

All these negative results of Baltic sea would make it uninteresting for scientists working on global ocean topics. But the Baltic also provides useful lessons on how to overcome the negative trends. Researchers publicise the Baltic sea as “a time machine for coastal areas worldwide”.

The changes in the sea have encouraged scientists and policymakers to take steps for reduction of ocean pollution. The efforts of the researchers have bought success. In the 1980s, the countries surrounding the sea managed to reduce nutrient inputs.

The Baltic Sea is believed to contribute to achieving the UN’s Sustainable Development Goal 14 — the conservation and sustainable use of the oceans, seas and marine resources.

Human actions have affected the world negatively. It’s time we all start learning from our past and stop making the same mistakes. The Baltic sea is used as a model to help the scientists and policymakers to avoid those mistakes. The model can be used to develop solutions for the problems caused in the ocean by human action.