M. Bonisławska - Department of Aquatic Sozology, West Pomeranian University of Technology Szczecin, K. Królewicza Street ۴B, ۷۱-۵۵۰ Szczecin, Poland.
A. Nędzarek - Department of Aquatic Sozology, West Pomeranian University of Technology Szczecin, K. Królewicza Street ۴B, ۷۱-۵۵۰ Szczecin, Poland.
J. Szulc - Department of Hydrobiology, Ichthyology and Biotechnology of Reproduction, West Pomeranian University of Technology Szczecin, K. Królewicza Street ۴, ۷۱-۵۵۰ Szczecin, Poland.
A. Tański - Department of Hydrobiology, Ichthyology and Biotechnology of Reproduction, West Pomeranian University of Technology Szczecin, K. Królewicza Street ۴, ۷۱-۵۵۰ Szczecin, Poland.
A. Torz - Department of Aquatic Sozology, West Pomeranian University of Technology Szczecin, K. Królewicza Street ۴B, ۷۱-۵۵۰ Szczecin, Poland.

The objective of the research was to test the effect of iron and aluminium coagulants commonly used for lake re-cultivation, on the pike sperm motility and fertilisation. The coagulants caused changes in the analyzed hydrochemical parameters of the water such as: Fe, Mg۲+, TSS, SO۴۲- and Cl-. Selected parameters of sperm motility: MOT, VCL, VSL, VAP, LIN were estimated using CASA. The sperm motility at the moment of activation was the highest in the control sample. With increasing the time of exposure the proportion of sperm motility in the analyzed semen decreased. In the samples with coagulants the values of MOT, VCL and VSL were smaller than in the control sample (statistically significant differences between the control and the samples with PIX and PAX were recorded in the ۲۵th-۳۰th second after activation). The percentage of fertilised eggs was the greatest in the control sample and in the PAX®۱۸ sample (۷۳.۱۱ and ۷۰.۴۲%, respectively), whereas in the PIX®۱۱۳ it was less than that (۵۴.۸۸%). The shortest larvae were those in the sample with coagulant PIX®۱۱۳. In the samples with PIX®۱۱۳ and PAX®۱۸ the survivorship of embryos compared to the control sample was the smallest (۴۳.۱۰ and ۵۱.۶۱%, respectively and control ۶۷.۶۰%) and the proportion of malformed larvae was the highest (۳۴.۸۲ and ۲۴.۵۲%, respectively and control ۱۵.۱۷%).

Coagulants, Lake, Fertilisation, Pike, Sperm motility