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Estuaries:
The Ocean's Nurseries
Estuaries
are important homes for many plants, mammals, reptiles, birds,
fish, snails, crabs, clams, and bably animals called larvae.
We call these habitats "wetlands" because the estuary
is frequently influenced by tides from the ocean and water
flowing from the land. After a heavy rainfall or during high
tides, there may be a lot of water and the estuary rises;
marshes become flooded with water. During low rainfall and
low tides, there is less water and the estuary level drops.
The salinity,
or amount of salt, of estuaries varies depending on the amount
of rain, and therefore freshwater runoff, entering the area.
In South Texas, there is very little rain. High temperatures
cause much evaporation, so estuaries can be very salty, also
known as hypersaline. The marsh plants and animals
are adapted to survive in very harsh conditions. Their adaptations
help them to live with changing salt and water levels. Along
the East Coast of the United States, there is more rain and
cooler temperatures; therefore, the estuaries are typically
less salty, or hyposaline.
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