DETERMINING LAKE METABOLISM USING DIEL OXYGEN TECHNIQUE: A CASE STUDY OF LAKE ABANT

Recently, diel oxygen technique has been intensively used to estimate gross primary production (GPP), net ecosystem production (NEP), and ecosystem respiration (R) from lakes, rivers, and lagoons. This study (1) estimated GPP, NEP, and R of Lake Abant using diel oxygen technique at three locations over the period of 2012 to 2014; and (2) built empirical models to predict temporal changes in GPP, NEP, and R. To estimate the lake metabolism components, dissolved oxygen concentration (DO, mg L-1), saturated dissolved oxygen value (O-2sat, %), and water temperature (T-w, degrees C) were continuously measured using in situ water quality monitoring probes, while solar radiation (SR, W m(-2)) and wind speed (WS, m s(-1)) were monitored using a meteorological station set up by the lake. Lake Abant was found to be of a net heterotrophic character (GPP/R < 1 and NEP < 0) for 2012, 2013 and 2014. Also, temporal GPP and R dynamics were modelled and validated on a monthly basis.