This Nature Reserve in northern Poland is composed of a lake, Jezioro Karaś, which is surrounded by mires and swamps. The Reserve has a relatively small extension of 815 hectares, but includes a variety of wetland habitats, from the lake’s open water to swampy forests. It is surrounded by farmland, and its boundaries can be clearly distinguished due to its different land uses. Human activities at and around the Site also include commercial fishing and forestry. The lake is divided into two different basins surrounded by a ring of reedbeds, after which successive habitats support important populations of waterfowl species such as spotted crake (Porzana porzana) and little crake (Porzana parva), which regularly breed there. More than 175 species are found within the Reserve, most of them protected under Polish legislation. Changes in plant communities have been noted, which may lead to changes to the Site’s ecological character. The Reserve is currently managed by the Forest District of Iława and the Regional Water Management Authority of Warsaw. The management plan in force grants strict protection, maintaining existing habitats and their hydrology.