PROTECTION OF WATERS
The aim of the National Park is the protection of its resources and the natural richness of its lakes and rivers. The tasks of the Park include, among
others: maintaining water conditions; protecting its waters against pollution; preserving diversity of currently occurring species of plants and animals,
their assemblages and communities and habitats; and also restoring those species of aquatic organisms which have become extinct as a result of human
As far as selected ecosystems are concerned, the Park protects also the course of spontaneous natural processes. Eight water reservoirs, i.e.: Lake Białe
Wigierskie, the complex of the lakes: Długie, Muliczne and Okrągłe, the small "suchary" lakes: Wądołek, Suchar Wielki and Konopniak and the sections of the
rivers: Wiatrołuża, Maniówka, Kamionka and Czarna Hańcza above Wigry Lake, are strictly protected. The combined area of the strictly protected
waters is 255.45 hectares which constitutes approximately 9% of the area of the Park’s waters. Thanks to many years of protection, the waters have become
an oasis for species avoiding the proximity of Man and a remarkably valuable place for research.
The biggest threat for the quality of the Park’s waters is their eutrophication. The process of eutrophication promotes the growth of algae suspended in
water. As a consequence, water transparency is decreased and oxygen is depleted. The depletion of oxygen induces a decrease in species diversity of aquatic
organisms. Moreover, species desirable for waters with low nutrient-enrichment (trophy) and often rare on national or international scale disappear.
In this case, one of the protective measures is maximum reduction of the flow of phosphorus and nitrogen compounds. This can be achieved by proper water
and sewage treatment in the surrounding of the Park’s waters. The tasks falling within the scope of extending sewerage system as well as the maintenance
and the modernization of sewage treatment plants are carried out by local governments. The Park supports their actions and it supports local governments in
their efforts to obtain funds necessary for further investments.
All the buildings under the Park’s management have been equipped with separate sewage treatment plants or connected to sewerage network. The biggest
tourist buildings of the Park, i.e. the beach by Lake Czarne near Krzywe and the camping site "Jastrzęby" by Lake Wigry have well equipped washing
facilities and toilets which guarantee the protection of the waters and soils from pollution.
The protection of the quality of certain water reservoirs takes place through shaping species composition and the number of fish aggregations. They
have a great influence on other aquatic ecosystems. Through preserving the high number of predatory fish feeding on small fish and yields of planktivorous
fish, big Plankton crustaceans such as Daphnia and many other big cladocerans which filter small algae out of water, are protected. Such
biomanipulation results in the increase of water transparency and positive changes in functioning aquatic ecosystems.
The tasks falling within the scope of water protection include preservation of those species of fish that are gradually disappearing as a result of eutrophication. To such species belong, among others, the whitefish and the powan. The protection of those species consists in supporting their natural
spawn with artificial stocking amounting to approximately 20 - 22 millions of specimens per year. It must be added that the stocking material is obtained
only from the wild stock of Lake Wigry. Thanks to stocking, the presence of the catfish and the lake trout in Lake Wigry has been restored.
One of the directions of the protection of the Park’s aquatic ecosystems is restoring small water reservoirs, both in the open agricultural landscapes and
in the Park’s forests. These reservoirs are significant habitats of many species of plants and invertebrates. Moreover, they are reproduction places of
amphibians. Nearby several restored waterholes in the region of Rosochaty Róg village, the Park has marked out and arranged an educational trail. The trail
is called "Płazy" (Amphibians) and there you can learn a lot about the natural value of those reservoirs.