OXYGEN IN LAKES, STREAMS,

AND RESERVOIRS

SOLUBILITY OF OXYGEN IN WATER RELATIVE TO PRESSURE

SOLUBILITY OF OXYGEN IN WATER RELATIVE TO TEMPERATURE

OXYGEN

SOURCES• ATMOSPHERE• PHOTOSYNTHESIS

LOSSES• CHEMICAL

– HUMIC ACIDS– IRON

• COMMUNITY METABOLISM

RED MUD – BLACK MUD

ORTHOGRADE OXYGEN CURVE

CLINOGRADE OXYGEN CURVE

CHANGE IN SEASONS IN A DIMICTIC LAKE

HOW COULD TWO SIMILAR LAKES HAVE SUCH DIFFERENT OXYGEN

PROFILES IN SUMMER?

CHANGE IN OXYGEN PROFILE THROUGH A SUMMER SEASON

HETEROGRADE OXYGEN CURVES

SUPPOSE A LAKE HAS THE FOLLOWING CLINOGRADE OXYGEN CURVE AT THE END OF

THE SUMMER SEASON

CASCADE OF EVENTS LEADING TO TURNOVER WITH CHANGE IN OXYGEN

PROFILE

OXYGEN CONCENTRATION UNDER CLEAR ICE

LATER IN WINTER

WARMING OF A LAKE DURING SPRING AND EARLY SUMMER

LONGITUDINAL OXYGEN CONCENTRATION IN A STREAM

DAILY OXYGEN CYCLE

OXYGEN CYCLE IN LAKE ERIE BASIN

LAKE NASSER• Surface area [km2] 6,000 • Volume [km3] 162 • Maximum depth [m]

110 • Mean depth [m] 70 • Water level Regulated

Normal range of annual water level fluctuation [m] 25

• Length of shoreline [km] ca. 9,000

• Catchment area [km2] 2,849,000

LONGITUDINAL PROFILE OF LAKE NASSER

LAKE NASSER OXYGEN

OXYGEN DEFICIT INCREASES WITH

• INCREASED PHYTOPLANKTON PRODUCTION• INCREASED PHOSPHATE• INCREASE IN HYPOLIMNETIC VOLUME

OXYGEN DEFICIT PROPORTIONAL TO THE INVERSE OF THE EPILIMNETIC TRANSPARENCY

Example: Diamond Lake in Oregon

DO DYNAMICS IN SURFACE WATERS (WETZEL, TABLE 9-2)

STREAM RESERVOIR LAKE

DO USUALLY HIGH HIGH HORIZONTAL VARIABILITY, USUALLY WARMER

SMALL HORIZONTAL VARIABILITY, USUALLY COOLER

OXYGEN UPTAKE FROM ATMOSPHERE

HIGH MODERATE VARIABLE TO LOW

DIURNAL VARIATION IN OXYGEN

HIGH MODEST LOW