Water Biomes

Water Biomes

Marshland is covered with grasses, reeds, sedges, and cattails. These

plants all have their roots in soil covered or saturated with water and its

leaves held above water.Marshes may be freshwater or salt. Freshwater marshes

develop along the shallow edges of lakes and slow-moving rivers, forming when

ponds and lakes become filled with sediment. Salt marshes occur on coastal tidal

flats. Inland salt marshes occupy the edges of lakes. They affect the supply of

nutrients, the movement of water, and the type and deposition of sediment.

Salt marshes are best developed on the Atlantic coasts of North America

and Europe. In eastern North America the low marsh is dominated by a single

species, salt-marsh cordgrass. The high marsh consists of a short cordgrass

called hay, spike grass, and glasswort. Glasswort is the dominant plant of

Pacific Coast salt marshes.

Freshwater marshes provide nesting and wintering habitats for waterfowl

and shorebirds, muskrats, frogs, and many aquatic insects. Salt marshes are

wintering grounds for snow geese and ducks, a nesting habitat for herons and

rails, and a source of nutrients for estuarine waters. Marshes are important in

flood control, in sustaining high-water tables, and as settling basins to

reduce pollution downstream. Despite their great environmental value, marshes

are continually being destroyed by drainage and filling.

Marine Life, plants and animals of the sea, from the high-tide mark

along the shore to the depths of the ocean. These organisms fall into three

major groups: the benthos, plants such as kelp and animals such as brittle stars

that live on or depend on the bottom; the nekton, swimming animals such as

fishes and whales that move independently of water currents; and plankton,

various small to microscopic organisms that are carried along by the currents.

Shore Life, the essentially marine organisms that inhabit the region

bounded on one side by the height of the extreme high tide and on the other by

the height of the extreme low tide. Within these boundaries organisms face a

severe environment imposed by the rise and fall of tides. For up to half of a

24-hour period, the environment is marine; the rest of the time it is exposed,

with terrestrial extremes in temperature and the drying effects of wind and sun.

Life on rocky shores, best developed on northern coasts, is separated

into distinct zones that reflect the length of time each zone is exposed. At the

highest position on the rocks is the black zone, marked by blue-green algae.

This transition area between land and the marine environment is flooded only

during the high spring. Below the black zone lies the white zone, where