Environmental Assessment
Volume E-4.3
Tailings Facility
Fish and Aquatic Resources
Ambatovy Project
184
January 2006
Table 4.3-8 Residual Impact Classification for Effects on Aquatic Habitat
Phase
Direction Magnitude Geographic
Extent
Duration Reversibility Frequency
Environmental
Consequence
Effect: Elimination of Riparian, Instream and Wetlands Aquatic Habitats
construction negative
high
local
long-term
no
medium
high
operations
negative
high
local
long-term
no
medium
high
Effect: Downstream Watershed Flow and Water Quality Changes
construction negative
low
local
medium-
term
no
medium
low
operations
negative
high
local
medium-
term
no
medium
high
closure
negative
low
local
long-term
no
medium
low
Effect: Habitat Disturbance and Water Quality Changes from Infrastructure (Service Corridor)
construction negative
low
local
short-
term
yes
low
negligible
operations
negative
low
local
long-term
yes
low
negligible
Effect: tailings facility reclamation
(a)
closure
positive
n/a
n/a
n/a
n/a
n/a
n/a
(a)
Effect during closure assumed only if viable aquatic habitat can be restored.
n/a = Criteria not ranked for positive effects.
The area downstream from the tailings is largely disturbed, however it still
maintains a good diversity of fish and aquatic resources. Given the predicted
high residual impact to these aquatic habitats, the proponents propose to discuss
strategies for improved management techniques with local stakeholders and
Malagasy fisheries experts.
Monitoring
No monitoring is proposed specifically for construction or operational effects on
aquatic habitat within the tailings disturbance area, as these units will be
eliminated during development of the facility. However, water quality and water
flow will be monitored in release waters and downstream, and during
construction, as described in Volume E, Sections 3.8 and 3.10. Selected aquatic
resources will also be monitored downstream of the tailings, to test impact
predictions. Post-disturbance monitoring of stream flow and water quality will
be implemented to ensure the effectiveness and integrity of reclaimed tailings
area.
