LAGOON (Fr. lagune,

See also:

• LAT

Lat. lacuna, a

See also:

• POOL

pool)  , a term applied to (I) a sheet of salt or brackish water near the sea, (2) a sheet of fresh water of no great depth or extent, (3) the expanse of smooth water enclosed by an atoll . Sea lagoons are formed only where the shores are low and protected from wave action . Under these conditions a bar may be raised above sea-level or a spit may grow until its end touches the land . The enclosed shallow water is then isolated in a wide stretch, the seaward banks broaden, and the lagoon becomes a permanent area of still shallow water with peculiar faunal features . In the old lake plains of Australia there are occasional wide and shallow depressions where water collects permanently . Large numbers of aquatic birds, black swans, wild duck, teal, migrant spoon-bills or pelicans, resort to these fresh-water lagoons .