The effects of climate change and nutrient pollution in the Baltic Sea are causing dead zones and promoting the spread of disease-causing pathogens. The Baltic Sea Action Plan (BASAP) could prevent the catastrophic consequences for the environment and economy if implemented perfectly. However, the plan’s implementation is slow, and scientists are concerned about the future of the Baltic Sea.
The excessive use of fertilizers and resulting nutrient concentration led to an 8,850-kilometer-long algae carpet in the Atlantic in 2018. A recent study also found that climate change and rising surface temperatures in the oceans trigger changes in phytoplankton distribution, which could endanger food chains in the oceans. However, the Baltic Sea is even more sensitive to changes in temperature and nutrient inputs due to its location and lack of fresh water supply. The toxic blue-green algae bloom in the Baltic Sea creates life-threatening dead zones due to its high oxygen consumption. The BASAP aims to reduce nutrient inputs into the Baltic Sea, but its implementation is slow. Scientists at the Leibniz Institute for Baltic Sea Research Warnemünde (IOW) have investigated the future of the Baltic Sea and found that the region will change significantly due to climate change.
The results of the computer simulation show that the surface temperature of the Baltic Sea could increase due to heatwaves in the next thirty years. By 2100, the average surface water temperature could be two to three degrees higher, and the sea temperature could be above 18 degrees Celsius for up to a month longer each year. Despite the positive impact on tourism, higher sea temperatures could accelerate algae growth and cause oxygen depletion in the sea, negatively affecting the environment and the economy. Furthermore, nutrient pollution could increase the probability of extreme blue-green algae blooms by 1,000 percent by the end of the century, and disease-causing bacteria could spread more easily in warm seawater. The study concludes that a perfect implementation of the BASAP and a limitation of climate change are necessary to maintain a good environmental state of the Baltic Sea and prevent the dangerous algae bloom from spreading further.
