Dynamics of organic matter in the changing environment of a stratified marine lake over two decades.

The marine lake (Rogoznica Lake), which fluctuates between stratified and holomictic conditions, is a unique environment on the eastern Adriatic coast affected by environmental changes. These changes are reflected in the warming of the water column, the apparent deoxygenation of the epilimnion, and the accumulation of organic matter (OM), toxic sulfide, and ammonium in the anoxic hypolimnion. Since the early 1990s, the volume of anoxic water has increased as the chemocline has moved to the surface water layer.