Poland on the way to SDGs. Report 2025

Seas and oceans cover almost three quarters of the Earth's surface, and natural marine ecosystems are increasingly affected by human activity. Data from the Copernicus Marine Environment Monitoring Service (CMEMS) indicate a gradual increase in the acidity of sea and ocean waters, which poses a significant threat to marine life and the biodiversity of aquatic ecosystems. Since 1990, the pH of ocean waters has fallen from 8.12 to 8.06. The main cause of these changes is the increasing emissions of CO₂ into the atmosphere. This gas is absorbed by seas and oceans, leading to their acidification. The increase in water acidity harms marine organisms, especially those that build their skeletons from calcium carbonate, such as corals, molluscs and plankton.

In order to protect and enhance natural biodiversity, Key Biodiversity Areas (KBAs) are being established according to uniform international criteria developed by the International Union for Conservation of Nature (IUCN). These areas are not protected by definition, but serve the purpose of drawing attention to unique territories of high natural value and promoting their protection. Marine KBAs are protected to the largest extent in Europe (72% under protection). In Poland, there are 170 KBAs, which is fewer than in 2020 (175). This fall results from the fact that areas meeting similar criteria have been joint together. However, the total size of these areas has increased from 60,000 km² to nearly 64,000 km². Twelve of Poland's KBAs are located in the marine environment and stretch across 8,000 km², and 90% of them is protected. The high percentage of protected marine areas in Poland results from, among other factors, the country joining the EU. Upon Poland’s accession, some of the areas became protected in the framework of the Natura 2000 programme. Before then, only 16% of Poland’s key marine areas were protected. Bulgaria, Malta and Estonia are the European leaders in protecting their key marine areas, with almost all these areas protected. The smallest proportion of key marine areas under protection is found in Cyprus (50%) and Sweden and Finland (around 60% each).

The biodiversity of seas and oceans is threatened by several factors, including overfishing, i.e. excessive and uncontrolled fishing, which reduces fish populations below safe levels of reproduction. In order to monitor the status of fish, they are divided into three groups: overexploited, fully exploited and underexploited stocks of fish. The two latter groups are considered biologically sustainable. In the EU marine waters, more and more stocks of fish are being maintained at safe, biologically renewable levels. Since 2015, the proportion of such stocks has increased from 42% to 61%. This is thanks to, among other things, the improvement in the north-east Atlantic (including the Baltic Sea), where the proportion of safe stocks has increased from 56% to 79%.

The ecological condition of the Baltic Sea and its lagoons is varied, but most often it is assessed as poor or bad. Large amounts of organic and biogenic substances carried by rivers end up in the sea. The deteriorating condition of its waters manifests itself in several ways, e.g. in an increase in the biochemical oxygen demand, from 88,000 tonnes per year in 2015 to 115,000 tonnes in 2022. Another problem is the growing amount of nitrogen in the Baltic Sea (41% more of it than in 2015), which contributes to the intensification of eutrophication, among other things. On the positive side, there has been a decrease in the amount of phosphorus in the Baltic Sea (by 19% during this period). However, this does not fully compensate for the negative impact of the increasing amount of nitrogen. Another positive development has been the gradual decrease in the amount of heavy metals in rivers flowing into the Baltic Sea, observed in recent years. Between 2015 and 2022, the amount of most heavy metals in Polish rivers flowing into the sea decreased. The amount of chromium and mercury fell by 100% each, the amount of zinc by 88%, the amount of copper by 72%, and that of lead and cadmium declined by about 50% each. Nickel was the exception here, as its amount increased by 9% in the studied period.

Annual catches of fish and other marine organisms by the Polish fishing fleet fell from 187,000 tonnes in 2015 to 160,000 tonnes in 2023. Deep-sea catches increased by 25%, while fewer and fewer fish were caught in the Baltic Sea (a 30% decline). This has reduced the ratio of the Baltic-sea catches to deep-sea catches. In 2015, Polish fleets caught 2.6 times more fish in the Baltic Sea than during deep-sea expeditions, and currently it is 1.5 times more.

Polish fishermen conduct most of their fishing in the Baltic Sea. In 2023, 59% of Polish sea catches came from Baltic fisheries, compared to 72% in 2015. Sprats dominate the Baltic catches, accounting for 66% of all fish caught. Herring constitutes 22% and flatfish 8% of all catches. Cod, which used to be much more important, now accounts for only 0.2% of total catches. To compare, in 2015, sprats accounted for 49% of fish caught in the Baltic Sea, herring for 30%, and cod for 10%.

The Polish fishing fleet conducts deep-sea fishing mainly in the Pacific Ocean and north-eastern Atlantic fisheries. In 2023, 41% of all fish and invertebrates caught by Polish fishermen came from these waters. The structure of deep-sea catches is varied. Horse mackerel accounts for the largest share of all catches (37%), and invertebrates for the smallest (1%). The remaining 62% of catches is made up of various sea fish, such as herring, cod, mackerel and blue whiting. To compare, in 2015, horse mackerel also dominated the catches (76%). Among other types of fish caught in that period there was e.g. mackerel (7%) and hake (2%).

Since 2015, the degree of exploitation of fisheries in the Baltic Sea has decreased significantly. Currently, only 25% of fish stocks are overfished, compared to as much as 60% in 2015. More and more stocks of fish are being kept in balance: currently 67% of them are exploited sustainably, compared to 40% in 2015. To protect fish stocks, the EU has introduced rules for managing fishing fleets under the Common Fisheries Policy. For the Baltic Sea macro-region, a special multi-annual plan for cod, herring and sprat stocks has been developed. In its framework, there has been e.g. a ban on cod fishing since mid-2019 due to overfishing and deteriorating environmental conditions (e.g. pressure from other species on cod roe).