Environmental Assessment
Volume B-4.3
Mine
Fish and Aquatic Resources
Ambatovy Project
261
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 Ephemeral Pond Mine Site 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
low
local
medium-
term
no
medium
low
closure
negative
low
local
long-
term
no
medium
low
Effect: Habitat Disturbance and Water Quality Changes from Infrastructure
construction negative
low
local
short-
term
yes
low
negligible
operations
negative
low
local
long-
term
yes
medium
low
Effect: Mine Site Reclamation and Protected Areas
operations
(a)
positive
low
local
long-
term
n/a
low
low
closure
positive
low
local
long-
term
n/a
low
low
(a)
Effect during operations assumed by development of protected areas; effect during closure from both reclamation activities
and protected areas.
The high residual impacts to aquatic habitats in the LSA are linked to fish loss in
reaches of streams that are lost to the mine footprint, even with azonal protection
areas on site. This result emphasizes the need to identify off-site compensatory
areas for the protection of off-site azonal forest areas and associated aquatic
habitats.
Monitoring
No monitoring is proposed specifically for construction or operational effects on
aquatic habitat within the immediate mine disturbance area, as these units will be
totally eliminated during development of the mine. Water quality and water flow
or levels will be monitored in release waters and downstream as described in
Volume B, Sections 3.8 and 3.9. Post closure monitoring of flow and water
quality will be continued to ensure the effectiveness and integrity of reclamation
activities.
