Chełkowski Z., Łysak A., Chełkowska B., Filipiak J., 1999. Dominance and occurrence constancy of the fish species in the lower Płonia River. Acta Ichthyol. Piscat. 29 (2): 13-29.
The fish fauna of the lower Płonia River, above and below, the discharge point of the partly treated manure from the Pig Farm at Kołbacz-was surveyed in the years of 1992-1994. Electrofishing conducted four times on the same sections of the river yielded a total of 5 773 fishes, representing 21 species. The fishes belonged to 8 families and they were assigned to four feeding guilds. The highest occurrence constancy index (100%) was observed in roach, perch, and pike. The above species represented also the highest dominance index (67.71, 14.77, and 4.07% respectively).