Page 127 - (DK) Ocean - The Definitive Visual Guide

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ALGAE-COVERED MUDFLATS
Some mudflats, such as these in Alaska, become
heavily encrusted with green algae. The algae
is often itself colonized by large numbers of
tiny marine snails.

HUMAN IMPACT
Animal Life
CONSERVING Measured by the amount of organic matter (the base material for food
SALT MARSHES chains) that they produce, salt marshes are extremely productive habitats. Most
of this material comes from decaying plant material. When plants die, they are
Salt marshes are threatened partially decomposed by bacteria and fungi, and the resulting detritus is
worldwide through being built consumed by animals such as worms, mussels, snails, crabs, shrimp, and
on, converted to farmland, or even
used as waste dumps. Over half of amphipods living in the marsh, and zooplankton living in the salt water. These
the original salt marshes in the US, in turn provide food for larger animals. Salt marshes provide nursery areas for
for example, have been destroyed. many species of fish, and feeding and nesting sites for birds such as egrets, herons,
This is regrettable, as salt marshes harriers, and terns. Tidal flats are NATTERJACK TOAD
are valuable wildlife habitats and home to many types of crustaceans, This toad, found in parts of
centers of biodiversity. western and northern Europe,
worms, and mollusks, which either
feed on the surface or burrow beneath inhabits upper salt marsh
habitats (just below the high
it. These in turn provide food for marsh), where it uses shallow
enormous numbers of wading birds. ponds to breed.

GREAT EGRET
A common inhabitant of salt marshes in the OCEAN ENVIRONMENTS
USA and parts of east Asia, the Great Egret,
and closely related Eastern Great Egret, feeds
on small fish, invertebrates, and small mice.
MARSH HOUSING DEVELOPMENT
This coastal development in Myrtle Beach, LUGWORM CASTS
South Carolina, has been built on top of a Lugworms live in burrows some 8–16 in
drained salt marsh. However, the adjoining (20–40 cm) deep in tidal flats. They feed by
area of marsh has been carefully preserved. taking in sand or mud, digesting any organic
matter, and excreting the rest as a cast.