Variability of Bio-Optical Parameters in Lake Jasień Północny and Lake Jasień Południowy

Bio-optical properties of water in two lakes from the Bytow district, Jasień Południowy (JS) and Jasień Północny (JN), were measured between 2007 and 2010. These lakes were chosen as reference for research in the Regional Environment Monitoring System (Wojewódzki Program Monitoringu Środowiska) between 2007 and 2009. The research concerned mainly OSCs (Optically Significant Constituents) such as chlorophyl a, SPM (Suspended Particulate Matter), CDOM (Colored Dissolved Organic Matter) and optical parameters of water (Secchi depth z_SD, diffuse light attenuation coefficient K_{d, PAR}). The aim of this article is to present temporal variability of OSC and optical properties in the investigated lakes as well as the relation between OSCs and the optical properties of water. The research has shown that the variability in the properties of water of these lakes is quite significant: concentration of chlorophyl C_Chl varied from 1.3 to 32.3 mg m⁻³ and the K_{d, PAR} coefficient from 0.42 to 1.05 m⁻¹. The obtained results were compared with the same parameters from other lakes in this region. The variability in the optical properties depend on the season and the biological activity of phytoplankton. Regression analyses showed a high correlation of optical properties of water with C_Chl and C_SPM, and no correlation with CDOM concentration. The highest determination coefficient was obtained for the optical parameters correlated with the three OSCs. The presented results show not only annual variability and variability between the years but also an influence of OSC elements on the optical properties of lakes.