324
M.-L. De Casabianca
13.3.1.2 Prevost Lagoon
In the Prevost lagoon, the dominant macrophyte is Ulva rigida
(rotundata) with a mean biomass of 4 kg m -2 (Riouall 1976; De
Casabianca-Chassany 1989). It tends to decompose into particulate
matter (De Casabianca-Chassany 1979a; Figs. 13.11,13.12).
300
..... ,
"0
'l'
200
E
:i
.....
..
.c
~
100
C
OJ
0
40
S' In
30
D.
.....
>..
:5
Ii
20
In
10
5000
..... ..
.c
DI
"I 4000
.. ;
N
3000
,
E
DI
..... 2000
.. .. . .
~ 1000
iii
0
(a)
(b)
(0)
J F M A M J J
Fig. 13.11. Prevost lagoon. Seasonal
variations of Uiva biomass in the
natural environment and in cage culture. a Sunlight: MJ m- 2 d- 1 ; b salinity: PSU; c biomass: g m -2 wet weight