The sea

2. LOTIC ECOSYSTEM
-flowing water
-characterized by inputs of detrital materials from
terrestrial sources and current of varying velocities the
carry nutrients and other material downstream.
■ Streams - bodies of moving water, contained within a bank (sides)
and bed (bottom).
■ Rivers - natural streams of water of fairly large size flowing in a
definite course or channel or series of diverging and converging
channels

3. LENTIC ECOSYSTEMS
– still water
■ Ponds - small body of freshwater, with no stream draining it - often fed
by an underground spring
■ Lakes - larger body of freshwater, usually drained by a stream. May be
naturally occurring or man-made.
■ Wetlands - region of land that holds a great deal of water for significant
periods of time, and that contains specialized
plants able to grow in these wet conditions

4. MARINE ECOLOGY
■ Provides ecological riches of about 250, 000 different
plants and animals.
■ Marine ecosystems cover approximately 71% of the
Earth's surface and contain approximately 97% of the
planet's water.

5. FEATURES OF THE SEA
■ 1. The sea is big; it covers more than 70% of the earth’s surface.
■ 2. The sea is deep; in some areas, the ocean bottom lies more than
6 miles (10 km) below the surface.
■ 3. The sea is continuous; not separated as land and freshwater
habitats.The chief barriers to free movement of marine’s
organism are temperature, salinity, and depth.
■ 4. The sea is in continuous circulation.

6. ■ 5. The sea is dominated by waves of many kinds and tides produced
by the pull of moons and the sun.
■ 6. The sea is salty.The salinity of the open sea is fairly constant.
Averaging about 35 ppt (parts per thousand)
■ 7. The concentration of dissolved nutrients is low and constitute and
important limiting factors in determining the size of marine
■ 8. The ocean and some groups of organism that live in it are older than
the ocean floor which is constantly being altered and renewed by
tectonic and sedimentary processes.

7. TEMPERATURE
■ The surface of coastal waters is coolest at dawn
and warmest at dust. In general, sea water is
never more than 2° to 3° below the freezing
point of fresh water and warmer than 27°.

8. ZONATION
The water column is subdivided into
distinct zones by water depth and distance
from shore.This is based on water depth and
population composition.The distinct zones
are:

10. Prepared by:
Rita Mae V. Montecillo