Environmental Assessment
Volume B-4.3
Mine
Fish and Aquatic Resources
Ambatovy Project
255
January 2006
Table 4.3-5 Impact Description Criteria for Fish and Aquatic Resources
Direction
Magnitude
Geographic Extent
Duration
Reversibility
Frequency
positive
,
negative
or
neutral
for the
measurement
endpoints
negligible
: no
measurable effect on
the measurement
endpoint
low
: <10% change in
measurement
endpoint
moderate
: 10 to 20%
change in
measurement
endpoint
high
: >20% change
in measurement
endpoint
local
: effect restricted
to the LSA
regional
: effect
extends beyond the
LSA into the regional
study area (RSA)
beyond
regional
:
effect extends beyond
the RSA
short-term
:
<3 years
medium-
term
: 3 to
30 years
long-term
:
>30 years
reversible
or
irreversible
low
: occurs
once
medium
:
occurs
intermittently
high
: occurs
continuously
4.3.5.4 Mitigation
Mitigations that will moderate the impact of habitat loss or alterations as a result
of riparian clearing, removal of streams and ponds, change in hydrology and
changes to water quality include the following:
Design Features
•
The project area footprint will include two areas of protected azonal
forest habitat and thus avoid a total loss of sensitive aquatic habitats.
The Ambatovy area will contain six of the remaining eight ephemeral
ponds in the study area, and also offer protection to portions of seven
headwater azonal transitional 1
st
order streams. The Analamay protected
area provides some headwater primary forest protection near the
Sakalava watershed.
•
Disturbances by sedimentation or water quality effects to the
Torotorofotsy watershed will be minimized to protect sensitive habitats
in the Torotorofotsy Wetlands and maintain existing ecosystem
conditions.
•
The mine water management plan will use variable instream flow
releases to simulate seasonal magnitude and duration of natural flows,
and therefore maintain natural ecosystem functions and aquatic
biodiversity.
•
Watercourse crossing guidelines and eco-plans will be implemented to
minimize in-water work and disturbance of aquatic /riparian habitat, and
control sediment levels.
•
Work closely with interest groups to align initiatives with their regional
conservation plans.
