Lake Sentani is thermally stable, with temperatures ranging from in the top ; the surface pH is 6.2-6.8, and plankton levels are low at 1-2 mg/L except in the westernmost basin, where water circulation is limited, turbidity is doubled, and seasonal algal blooms, with resultant fish mortality.
It may be small, but it harbors 34 species of fish, of which 13 are resident natives, 8 anadromous and 13 introduced.