Occurrence, threats and active protection of the lake minnow, Eupallasella percnurus (Pall.), in Mazowieckie Voivodeship in Poland

From March 2002 to May 2011 about a hundred water bodies in the Mazowieckie Voivodeship (Poland) were investigated with the goal of discovering new sites inhabited by the endangered cyprinid lake minnow, Eupallasella percnurus (Pall.). Ten sites were discovered that had been previously unknown. During the same period, six new sites were created by translocation of cultured juvenile individuals into suitable water bodies not inhabited by this species. These measures were undertaken as part of a long-term (2002-2015), voivodeship-wide program for the active protection of this species, which is the only one of its kind in Poland. Of the sixteen sites currently in existence, ten are suffering from advanced water basin shallowing and/or vegetation overgrowth. However, good water conditions throughout 2010 and in the first half of 2011 have meant that only six sites are presently considered as critically threatened, whereas seven appear to be of least vulnerability. At present, five sites (31.3% of all sites in the voivodeship) are protected within the European Ecological Natura 2000 Network.