The Ecology of the Seagrasses of South Florida - USGS National ...

0
5
10
E
d
N 15
f a
a
0
20
25
30
Figure 8. Depth distribution of four seagrasses on the northwest coast of Cuba, I =
Thalassia testudinum, 2 = S rin odium filiforme, 3 = Halo hila decipiens, 4 = H. :nye1-
m o m Susea 1g75). *r7nqodium is yi&nt in certain IoFal~t~es,
note the preponderance of Thalassia biomass and the absence of Halodule on the Cuban
coast.
bays of south Florida, the turbidity and exposure well. Exposed leaf surfaces will
therefore the maximum depth for rooted lose water constantly until dry, and there
plants can vary over short distances. is no constraint to water loss that would
Phi 11 ips (1960) recorded turtle grass 1 imi t drying (Gessner 1968). A1 though
ranging from 10 to 13 m (33 to 43 ft) in exposure to the air definitely occurs at
depth. In the relatively clear waters of certain low tides on shallow turtle grass
the back reef areas behind the Florida or shoal grass flats, unless it is
Keys, turtle grass is common to 6 or 7 m extremely brief, the exposed leaf surfaces
(20 or 23 ft) and occurs down to 10 rn (33 will be killed.
ft); by contrast, in the relatively turbid
portion of the "lakes" of Florida Bay,
maximum depths of only 2 m (7 ft) are Fol lowing exposure, the dead leaves
common. are commonly lost from the plant. Rafts
of dead seagrass leaves may be carried
2.10 EXPOSURE frm the shallow flats following the
spring low tides. Normally the rhizomes
The seagrasses of south Florida are are not damaged and the plants continue to
all subtidal plants that do not tolerate produce new leaves.
19