Abstract. Knowledge of the historical occurrence of the endangered cyprinid fish species, Eupallasella percnurus (Pall.), in today's Kujawsko-Pomorskie Voivodeship in Poland is sparse. However, a total of nine sites inhabited by this species had been identified by the end of the twentieth century, but only one of theses had survived into the early 2000s. The largest field inventory to date of this area was undertaken from 2005 to 2011 and nine new sites were recorded. Most of the newly discovered sites inhabited by E. percnurus are located in the Dobrzyñskie Lake District mesoregion, which is where this species has occurred in the past. Four of these sites have been designated as vulnerable and two as critically threatened. Immediate active protection measures are necessary to preserve E. percnurus at the two existing sites in the Special Protected Area PLH040013 "Cyprianka".

Abstract. This paper is a summary of the historic and current knowledge of the occurrence of lake minnow, Eupallasella percnurus (Pall.) in Pomorskie Voivodeship in Poland. It considers factors threatening the existence of this species, and determines possibilities for the conservation and protection of sites which it inhabits. Currently, E. percnurus is known to inhabit 102 sites in the voivodeship, which constitutes 59.3% of all known sites in Poland (172). The main threats to E. percnurus sites and/or populations in Pomorskie Voivodeship include the draining and drying up of water bodies and their transformation for recreational use. Currently, only 10 of the sites are classified as threatened to a low level, while 44 sites are endangered to a high level. Almost half of all the sites (45) are subject to protection within the framework of the European Ecological Natura 2000 Network, and these probably have the greatest chance of survival.

No abstract

In many regulated rivers, silver eels (Anguilla anguilla L.) experience significant mortality as they pass through small hydropower stations (HPS) during their downstream migration. There has been a huge collapse in the recruitment of this species, primarily because of the destruction of river–ocean connectivity with overfishing. The direct mortality caused by small hydro turbines varies between different places and depends on many factors. The aim of the present study was to assess the mortality rate of silvers eels passing through a small HPS equipped with a Francis turbine in a small Pomeranian river using acoustic telemetry. During the experiment, no direct mortality occurred as a result of passage through the HPS turbine. However, three individuals were believed to have suffered from injuries or passage trauma.

Abstract. This paper presents preliminary results of a comparison of the seasonal activity of lake minnows, Eupallasella percnurus (Pall.), and crucian carp, Carassius carassius (L.), in a few small water bodies. Field studies were conducted based on catches made with baited traps in periods without ice cover from April to December 2006. E. percnurus became active earlier than did C. carassius and their period of intense activity was longer. The first E. percnurus appeared in the traps in early April when the ice was still melting, and these fish were caught at a temperature range of 3.5-29.2°C. C. carassius were caught most abundantly in the beginning of May at temperatures from 15°C; this species was usually noted in traps at a narrower, but higher, temperature range in comparison with the E. percnurus. Additionally, the activity of both these species was similar with regard to weather conditions; both species were less active on cloudy days and when atmospheric pressure was increasing.