Transparency:

♤ Transparency affects the extent of light penetration.

♤ Suspended particulate matters such as clay, silt, phytoplankton, etc make the water turbid.

♤ Consequently it limits the extent of light penetration and the photosynthetic activity in a significant way.

Temperature:

♤ The water temperature changes less rapidly than the temperature of air because water has a considerably higher specific heat than air, i.e. larger amounts of heat energy must be added to or taken away from water to raise or lower its temperature.

♤ Since water temperatures are less subject to change, the aquatic organisms have narrow temperature tolerance limit.

♤ As a result, even small changes in water temperature are a great threat to the survival of aquatic organisms when compared to the changes in air temperatures in the terrestrial organisms.

The classification of organisms and limiting factors discussed here apply in general to all aquatic ecosystems - lakes,Ponds, Rivers, Streams, Estuaries, oceans and seas.

Do you know?

Bats are social animals. They hang UPSIDE DOWN when they sleep. They feed at night (they are “nocturnal”) and spend the day sleeping in caves or in tree tops. They are the second largest group of mammals after rodents.

4.2. LAKE ECOLOGY

Any - body of standing water, generally large enough in area and depth, irrespective of its hydrology , ecology, and other characteristics is generally known as lake.