Mammals of the Baltic Sea
All the animals inhabiting the Baltic Sea are under protection. These are three species of seals and the porpoise - the only Baltic cetacean. Until the beginning of the 20 th century the sea was abundant in these animals, yet since they feed chiefly on fish they were found harmful. There were awards granted to those who killed them. It soon led to almost total extermination of the Baltic seals and cetaceans. The attempts at restoring the population of those animals have been taking place for nearly 20 years. Presently, the main threat they may face is the fishing net they may entangle in. Once entangled, the animals suffocate as they fail to resurface for oxygen. Another threat is posed by environmental pollution which brings on diseases and problems related to reproduction. A third, very important factor, is the development of tourism and fishery. Lack of peace as well as noise scare the animals away from their habitat giving them with no chance to rest, which usually leads to exhaustion. This is the reason why it is forbidden to interfere with a resting seal.
The Seal Centre of the Hel Marine Station - it is a field station of the Marine Station belonging to the Institute of Oceanography at the University of Gdańsk. The main aim of the station is to restore a colony of the grey seal in the region of the southern Baltic Sea. Those seals, which require care or have been bred in the Centre, return to their natural environment remaining valuable source of information about the species, its migrations or health condition. The Centre performs also educational work and popularizes the mammals living in the Baltic Sea.
The porpoise (Phocaena phocaena)
Although the porpoise possesses its own monument in Gdynia, not every child knows that the Baltic Sea is inhabited by a relative of dolphins. Unfortunately, it is threatened with extinction. The knowledge about this animal is negligible due to its small number (estimated amount around 1,000). It weighs approximately 45- 70 kg with an approximate body length of 1.5 - 1.7 m. The animal is encountered in the region of the Gulf of Gdańsk and the Puck Bay. The stamp with a porpoise presents an emerged upper part of the porpoise's body revealing its nostrils and characteristic triangular dorsal fin.
The grey seal (Halichoreus grypus) - the largest of the Baltic seals with a body length up to 2.5 m. The weight of the males may exceed even 300 kg. After birth the young are covered with white fur. Once the seals were in abundance; now they are in rarity mainly encountered in the region of the Gulf of Gdańsk.
The harbour seal (Phoca vitulina) - also called a sea dog. In spite of the name it is the least numerous species of the Baltic Sea. It lives in colonies, swims fast and dives 150 meters deep. Its body is around 1.5 - 2 m. long and weighs around 100- 180 kg. The pups have an "adult" fur colour.
The ringed seal (Phoca hispida) - the jar seal - its name comes from light, ring spots on their back. It is the smallest Baltic seal 105- 170 cm long weighing 45- 140 kg. It leads rather lone life.
Courtesy : Poczta Polska
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