hypolimnion The lower, cooler, non-circulating water in a thermally stratified lake in summer. If, as often occurs, the thermocline is below the compensation level, the dissolved oxygen supply of the hypolimnion depletes gradually; replenishment by photosynthesis and by contact with the atmosphere is prevented. Re-oxygenation is possible only when the thermal stratification breaks down in autumn.

hypolimnion The lower, cooler, noncirculating water in a thermally stratified lake in summer. If, as often occurs, the thermocline is below the compensation level, the dissolved oxygen supply of the hypolimnion depletes gradually: replenishment by photosynthesis and by contact with the atmosphere are prevented. Re-oxygenation is possible only when the thermal stratification breaks down in autumn.

hypolimnion The lower, cooler, non-circulating water in a thermally stratified lake in summer. If, as often occurs, the thermocline is below the compensation level, the dissolved oxygen supply of the hypolimnion depletes gradually: replenishment by photosynthesis and by contact with the atmosphere is prevented. Re-oxygenation is possible only when the thermal stratification breaks down in autumn.

hypolimnion The lower layer of water in a lake. See thermocline.