France - The Mediterranean Lagoons
• Brackish areas
III Marine areas
o Freshwater areas
111
i
:--+
Corsica - - -:
~------------------------,
,
------------------------~
311
Fig. 13.2. Corsican lagoons and the classification of their littoral zones according to
pluriannual salinity regimes
The bottom of the lagoons can be divided into two zones: a bare zone
close to the edge, partly subjected to emersion due to variations in the
water level of the lagoon. This entire zone may be invaded by floating
macrophytes during spring. A second zone is characterized by the presence of seagrass beds and their associated fauna.
This study covers diverse shores from lagoons of various types, with
slopes of 3 to 100%, with various substrates and with different degrees of
emersion. As the plant populations develop in spring from elements that
have survived winter, the extremes of salinity variation encompassing the
reproductive period of these species from April to October, i.e. practically the salinity minimum in spring and the maximum in autumn, can
be used as a criterion to define such populations and to classify the
different biotopes (cf. Fig. 13.1).