Wetland & Fish Ecology - Enviro Dynamics Namibia

69
Okatana channel
of marginal vegetation,
due to construction.
-M Con+
SF1-2
by
construction
careful
functioning of iishana
B. Habitats lost due
to deepening and
lining of Okatana
channel
Decline in aquatic
vegetation, habitats,
aquatic invertebrates
and fish, general decline
in productivity
L
MT
LT
SER
-M
H
Ong
Of limited duration if
substrate is replaced
or sediment allowed
to settle, but
permanent if lined
channel is to
regularly “cleared”
of vegetation
Replace substrate
Do not clean out
sediment
Keep oshana as natural
as possible, keep
margins.
L
Allow bottom and
marginal vegetation to
re-establish
Reduces self-cleansing
function of natural
wetland fauna and flora
L LT MOD
-M
M
Ong
Natural vegetation
cover for aquatic life
Cover lining with
original substrate
/surface material or
allow sediment to
collect again naturally
and encourage
seeding of plants and
colonisation by inverts
on bottom and at
margins
L
B. Salinisation due
to deepening of
Okatana channel
Decline in water quality
that could cause more
saline-sensitive species to
R ST MOD
-M
M
Cons+
Limited or no
additional
salinisation
Check soil profile in
oshana
to determine salinity of
L
Draft Environmental Impact Assessment: Oshakati Flood Mitigation Project
Specialist Study: Wetland Ecology and Fish Ecology Imputs
July 2012