The study presents the results of the research into different phosphorus forms in the bottom sediments of anthropogenic limnic ecosystems i.e. the reservoirs of Pławniowice, Rybnik and Goczałkowice (SP). The bottom sediments of dam reservoirs were investigated by chemical extraction procedure for phosphorus forms. The lowest value of the mean AAP form percentage in the Pławniowice bottom sediments reflected the effect of reclamation with the hypolimnetic removal that had been conducted in the reservoir since 2003. The highest percentage of the RDP form (2%) was found in the Goczałkowice bottom sediments. The order of the specific speciation forms in the bottom sediments of the examined reservoirs was:

Rybnik: AAP > EP > WDP > RDP; 4,630> 3,740 > 117 > 65 > 3.5 mgP/kg

Pławniowice: AAP > EP > WDP > RDP; 916 > 783 > 107 > 15 > 1.4 mgP/kg

Goczałkowice: AAP > WDP > EP > RDP; 686 > 628 > 51 > 7 > 0.14 mgP/kg

The mutual correlations between the phosphorus speciation forms (AAP : EP : WDP : RDP) were as follows:

Rybnik: 1,323 : 1,068 : 33 : 18 : 1;

Pławniowice: 654 : 559 : 76 : 11 : 1;

Goczałkowice: 4,900 : 4,485 : 364 : 50 : 1.

The comparison of the mean concentration values for specific phosphorus forms in the bottom sediments of the three investigated reservoirs demonstrated that the Rybnik sediments had the highest contents of phosphorus. The contents in Pławniowice and Goczałkowice were 5-7 times lower