The Baltic is a specific sea - very young, not very salty, semi-closed, with limited water exchange with the rest of the marine world. It was formed only after the last glaciation receded, 11 thousand years ago, and over that time it has undergone many significant changes. Its fauna has changed along with it.

Initially, it was home to freshwater animals, and over time, deep-sea and cold-water species appeared. When there was a permanent ice cover, the first seals, the harp seals, settled in the Baltic Sea. In subsequent eras, as the climate warmed, they naturally moved on and were replaced by slightly more thermophilic species. Currently, three species of seals live permanently in the Baltic.

'They all came here from other waters. 11,000 years of the Baltic's history is too short a time for any local species to have emerged. Therefore, everything that lives in this sea originated from the North Atlantic', says Professor Jan Marcin Węsławski, a marine ecologist and director of the Institute of Oceanology of the Polish Academy of Sciences.

THREE BALTIC SEALS

The first seal species inhabiting the Baltic Sea today, and the least numerous one, is the common seal. This small animal loves to bask on rocks, especially in the western part of the sea, i.e. on the Swedish, Danish and Norwegian coasts.

The second most numerous is the smallest of the Baltic seals, the ringed seal. 'We can say that it is a relic of the cold period in the history of the Baltic Sea. That is why it lives in the northern part of the sea, mainly in the Gulf of Bothnia and the Gulf of Finland, and its characteristic feature is that it can only breed on ice', the researcher says.

At some point in history, grey seals also appeared. This is the largest and most numerous species of seals in the Baltic Sea. While there are few representatives of the other two species- - a few thousand ringed seals, only 600-700 common seals - the grey seal has achieved an undoubted ecological success. 'Perhaps because it is the largest one and +pushes away+ smaller species without mercy. Ultimately, it led to a situation in which at the beginning of the 20th century its population was estimated at over 100 thousand individuals', Węsławski describes.

SEALS VS. PEOPLE

However, the 'fat years' of seals did not go hand in hand with the satisfaction of fishermen. The International Council for the Exploration of the Sea (ICES), established in 1902, recognized them as the main pests of fishing and allowed intensive hunting of these animals. 'The Council issued an order aimed at limiting their population. Special bonuses were passed for shooting seals and their mass killing began. This was particularly true in Scandinavian countries, but also happened in pre-war Poland. The most hunted, of course, was the grey seal, because the other two species were not so conspicuous to fishermen. As a result, the population of Baltic seals was severely decimated', the expert says.

He adds that, in hindsight, it is clear that these actions were not fully justified. 'At that time, fishermen focused primarily on cod fishing, while the grey seal feeds practically exclusively on herring, and a little sprat. Of course, conflicts with fishermen occurred, because a seal is a very intelligent animal, with the intelligence of a dog, and when it sees a fish trapped in a net, it will reach for it. But it would be enough to scare them away from fishing grounds at a low cost, instead of shooting them en masse', Professor Jan Marcin Węsławski emphasises.

In the 1960s and 1970s, the Baltic Sea experienced the greatest environmental crisis in history, caused by the uncontrolled discharge of various types of pollutants into sea waters. As a result of the crisis, predators at the top of the food chain, including seals and white-tailed eagles, suffered the most. Ultimately, the grey seal population decreased from the initial 100,000 to 3,000-4,000 individuals.

CULLING IS NOT A SOLUTION

The animals that survived were so few in number that for many years they did not venture beyond several north-eastern areas of the Baltic Sea. During that time, they did not appear in Polish waters at all. It was not until the 1980s that extensive conservation measures were initiated, as a result of which the Baltic Sea gradually began to clean up. 'Protection of large predators was also introduced, which allowed the seal population to rebuild. In Sweden and Finland, these animals were even artificially fed. Today, the population of the Baltic grey seal numbers around 30,000', says the ecologist from the Polish Academy of Sciences.

The revival of the population resulted in seals starting to leave their home range, the archipelagos of Swedish and Finnish islands, and venturing into other regions of the sea. As a result, they also started to appear on Polish beaches.

'Remember, however, that they are only guests here. Poland does not have its own seal population, because our coast is completely unsuitable for their permanent habitat and they cannot reproduce here. They do visit us from Estonia, Finland and Sweden, especially in the mouth of the Vistula, because there are sandy shallows there, where they like to rest and hunt, undisturbed by humans', Węsławski emphasises.

Unfortunately, the more frequent visits of seals have caused another conflict with the fishing community. According to the professor, the culling of these predators, as advocated by fishermen (and supported by some politicians), is pointless. 'Such a measure can only be effective against resident animals, i.e. those living here permanently. It makes no sense for us, culling would not solve the problem', he says.

Instead, he and other scientists propose more rational methods, i.e. the use of seal deterrents and the introduction of a compensation system for fishermen. 'One effective solution is using modern fishing methods, such as cod cages, which prevent seals from eating fish from the nets. Acoustic devices that scare away predators and mechanical barriers in nets are also effective. Even leaving a fishing boat at the fishing spot will effectively discourage a seal from helping itself to fish', the expert says.

The second thing that would help resolve the conflict is a change in the regulations on compensation for people harmed by seals. 'The overall economic losses for fishermen in the Vistula estuary are not very significant - they reach PLN 300-400 thousand per year, which is not much compared, for example, to the farmers' losses caused by beavers. In addition, according to the regulations, the state is responsible for any losses caused by protected species, and it should pay compensation to the injured parties. Unfortunately, there is a legal problem here, because the EU's fishing policy states that a fish belongs to a fisherman only when it is pulled out of the net and loaded onto a boat. Therefore, a fish in the net eaten by a seal is not subject to compensation', Węsławski explains.

In his opinion, for the good of both seals and people, this regulation should be changed.

POLAND IS NOT A HOME FOR SEALS

Another issue raised by the scientist is the activities of nature conservation organizations. Some of them have become deeply involved in the protection of seals, promoting the slogan 'Give the seals back their home' and postulating the designation of zones exclusively for seals on the Polish coast, with no entry for people.

'This is a misguided and harmful idea, criticised by the scientific community. Firstly, because seals have no desire to rest on our beaches; they have never been their home. They are only interested in shallows near fishing nets. Secondly, such demands antagonize fishermen towards animals', the expert emphasises.

He reminds that in response to such campaigns, fishermen were suddenly blocked from setting their nets where they wanted, and were required to use expensive deterrents. Further restrictions caused the situation from the beginning of the 20th century to repeat itself - seals started to be viewed as enemies and pests.

'For years, we, scientists, have been repeating that seals should be protected, but in the right way, i.e. by adapting the plans for maintaining the species to the actual needs and situations. They should be left alone, not disturbed, but imaginary reserves should also not be created or life made difficult for fishermen, because seals come here only for a moment and then return home. The Polish coast is not and never has been their home', emphasises the expert from the Polish Academy of Sciences.

PAP - Science in Poland, Katarzyna Czechowicz

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