Are you spending your summer holidays at the Baltic Sea coast and are annoyed about bad weather and cold water? It won't be long before the complaints about the latter are over, but there is nothing to be happy about.

Scientists at the National Research Institute (Polish: Państwowy Instytut Badawczy) warn that the temperature in the Baltic Sea basin is rising dangerously. What does this mean for us and why shouldn’t warmer baths put us in a positive mood all?

The Baltic is a relatively small sea that is enclosed by many European countries including Poland, Denmark, Estonia, Finland, Sweden or Latvia. All these countries will soon be facing some serious and devastating changes.

The Institute of Environmental Protection – National Research Institute (IEP-NRI), which reports to the Polish Minister of Climate, has presented a worrying report. Researchers are warning that sea water temperatures are rising dangerously and the forecasts for the future are not at all good.

"The temperature increase of 0.08 degrees Celsius per decade in the Baltic Sea catchment area is higher than the average increase across the Earth estimated at 0.05 degrees Celsius. [...] The biggest changes will occur in the Gulf of Bothnia and the Bothnian Sea in the summer, and in the Gulf of Finland in the spring. The water temperature will increase by about two degrees Celsius in the southern part of the basin in the summer and by up to about four degrees Celsius in the northern part," the report reads.

The changes in the Baltic Sea's temperature are related to climate warming and, more specifically, to its consequences. The state of the sea is affected by the reduction of the ice cover and its duration, and a lengthening of the growing season. The projected changes are expected to affect not only the earlier occurrence of typical spring floods, but also the reduction of water salinity.

Should we rejoice at warmer water in the Baltic Sea? Of course not. It is as if we were celebrating the global warming. In no way do such changes positively affect neither our nor other organisms’ lives.

Researchers predict that one effect of the warming may be the displacement of cold-water organisms by warm-water species. Cod, for instance, is a cold-water fish, so it may simply leave the Baltic Sea in search for colder bodies of water.

Higher temperatures and lower salinity also increase the uptake of heavy metals by living organisms. This means that there will be marine animals with higher concentrations of metals on our plates, which may subsequently badly affect our health.

The timing of the ice cover formation and its extent is also not insignificant. Less ice and more heat is an easy recipe for disaster, as such conditions lead to the leaching of organic matter and nutrients from the sea.

"The longer the soil and sea remain unfrozen, the more time there will be for running water to wash soil, organic matter, and nutrients into the sea.

"As the amount of organic matter in the sea increases, the seawater becomes darker and cloudier yearly. As the nutrient load rises, eutrophication and blue-green algae will also increase. The growth of blue-green algae promotes eutrophication, which fuels a cycle of eutrophication," reads the Baltic Sea Action Group website.

Currently, one-fifth of the Baltic Sea is occupied by so-called dead zones, i.e. oxygen-free (or anaerobic) areas of the seabed that are formed as a result of eutrophication. As you can guess, the eventual expansion of such areas will lead to the death of even more living organisms.

The researchers point out, however, that the direction and intensity of some of the changes taking place in the basin are not fully understood. Nonetheless, the conclusions are inescapable - we should act now to reduce our negative impact on the state of the Baltic Sea.

"What can be said with certainty, however, is that in order to reduce our negative impact on the Baltic Sea, it is necessary to further reduce the anthropopressure associated with urbanisation, the development of intensive agriculture and industry. Numerous pollutants from these sources are transported to the sea via rivers and negatively affect marine ecosystem and both physical and chemical conditions in the sea," reads the report.

Source: PAP, ceo.com.pl, Baltic Sea Action Group, WP Tech