Geology Reference
In-Depth Information
Fig. 10 a
Morphological map of Oualidia lagoon;
b
Oualidia lagoon
'
s principal channel, with primary and secondary tidal inlet.
c
Morphological
map of Sidi Moussa lagoon.
d
Sidi Moussa lagoon
'
s principal and secondary channels
The geology of the Oualidia lagoon (Fig.
10
a, b) consists
of clayey sands, sandstones and calcareous and marl for-
mations of Late Jurassic age, overlain by Plio-Quaternary
consolidated dunes (Can
water, protection against
oods, organic production, special
biotope of bird species for nesting and breeding with high
heritage value (migratory birds), and growth of a remarkable
rot et al.
1982
; Taj-Eddine et al.
1985
; Witam
1988
; Ouadia
1998
; Fakir
2001
). The numer-
ous geological, ecological and biological
é
eld-area for pal-
aeoclimatic and climatic studies, drawing upon evidence of
historical weather events preserved in the
ora (Hammada
2007
). Moreover, it is a
investigations
ne-grained
made of this lagoon re
ect its regional and global impor-
tance. Furthermore, it is one of the few sites in Morocco
where traditional oyster cultivation has been developed since
the 1950s. The lagoon is characterized by special species
such as
Chondrus crispus
,
Palmaria palmata
,
Sacchoriza
polyschides
,
Enteromorpha crispa
and
Ulva linza
(Farid
et al.
2009
). The variety of species is in
sediments.
These wetlands are, however, subject
icts of
interest between the economy and ecology (Guo and Ma
2008
). The protection of bird species is dependent on the
protection of their wetland habitats. Without adequate con-
servation measures, these stopover sites may become the
weak link in the chain of migration, which, if broken, will
probably result in the extinction of the wild bird populations
that depend on them (Higuchi
1991
). Consequently, the
preservation of this heritage will contribute to improvements
in the quality of life of the local population. Due to anthro-
pogenic pressures, the wetland areas are at risk (drying, salt-
water intrusion in the coastal border, over-exploitation of
marine organisms, and destruction of natural barriers (sand
dunes etc.). Accordingly, a better understanding of these
ecosystems is necessary to improve and rationalize their
management in order to preserve them against environmental
threats. In fact, con
to con
uenced by envi-
ronmental factors, such as substratum, water temperature,
light, wave action, salinity and pH (Fang et al.
1996
).
The Sidi Moussa lagoon (Fig.
10
c, d) is a marginal sys-
tem with a signi
ed in the
semi-arid range (Atillah
1994
), and is characterized by warm
temperate climate (Maanan
2003
). Geomorphologically, it
consists of a depression resulting from the post-Ouljian
regression (Quaternary) (Bidet and Carruesco
1982
; Car-
ruesco
1989
). It is biologically rich, comprising a variety of
cant marine in
uence. It is classi
sh exhibiting seasonal variability (sole, bar, etc.) and sev-
eral invertebrates such as decapods, isopods, cnidarians,
gastropods and bivalves (Bennouna
1999
). Fishing is one of
the important activities in this area, but it is still traditional
and seasonal.
The Sidi Moussa-Oualidia lagoon complex has an
exceptionally rich and diverse heritage as it performs several
ecological functions such as: control and self-puri
icts of interests between the use of the
wetlands and ecosystem protection need careful evaluation to
contribute in the local development.
3.2.2 Zima Lake
The Zima Lake is a salt wetland of 600 ha (Fig.
11
). It has a
high ecological potential and is classi
cation of
ed as a
Ramsar
site,
