biological diversity and tropical forests in tunisia - PART

3.3. WETLANDS
In this docamect the term 'wetland' refers to permanent and temporary
fresh or brackish water bodies and their adjacent floodplain or zone of
influence. This includes all inland rivers and water bodies, coastal salt
lakes and marine lakes, (figure 6) but excludes the Mediterranean coast,
which is described in Section 3.1. Tunisia has more than 100 permanent
and temporary wetlands, many of which are of international importance.
Host of the wetlands are in the northern half of the country, especially
near the coast, and there is a fair interspersion almost everywhere but in
the Sahara.
Wstlands permit a variety of plant species to grow in ecosystems that
are otherwise often somewhat homoganous - especially in the steppes.
Numerous invertebrates, reptiles, amphibians, birds and mammals take
advantage of the cover and nutritiocal productivity of wetlands. Each
year mora than 75,000 flamingos, 400,000 anatids of many species, and
250,000 coots and moorhens use ~unisia's wetlands for nesting, migration
rest stops or wictering locations (Dir. Env. 1977). Macy spscies of rare
and endemic plants and animals are also found at wetlands.
Unfortunately, many of Tunisia's wetlands are being detrimentally
influencad by industrial complexes, urbac expansion, agricultural
developmsnt projects (dams, drainage), pesticide use, hunting pressure,
pollution and dessication (Dir . Env. 1977). The Tunisian government has
taken steps to protect some of the principal sites by creating permanent
ressrves and national parks (~ectioc 5.4). Howaver, the mers designation
of protected areas is often insufficiant in the face of heavy population
and economic pressures, as evidenced by the filling of Lake Tunis (see
3.3.1.3).
The factors that wetlands are most secsitiva to inclade:
Activities affecting water levels
Upstream dams
Draining of marshland for cultivation
Changes in water quality
Abnormal inputs of seawater or saline runoff
Chemical pollutants - herbicides, sewage, chemical waste
Actions reducing wetland areas
Cultivation of edge zones
Adjacent urban development
Filling and construction