Environmental Assessment
Volume C-4.3
Slurry Pipeline
Fish and Aquatic Resources
Ambatovy Project
140
January 2006
techniques will be used, linked to additional monitoring just before construction.
The prediction confidence for impact ratings for fish and aquatic communities at
and downstream of the watercourse crossings is therefore medium.
Closure and reclamation goals will include some habitat restoration and possibly
enhancement. The success of these initiatives is difficult to predict.
Table 4.3-10 Potential Effects and Residual Impacts for Aquatic Species
Abundance and Health in the Slurry Pipeline Area
Project
Period
Potential Effects
Mitigation
Residual Impacts
construction
avoidance, sublethal effects or
mortality depending on the levels
of TSS , or other
local effects on aquatic and
riparian habitat during instream
and service road or access road
construction
local water management
pre-construction assessment
of each crossing to select
most appropriate technique
erosion control design
systems
fish salvage program
high magnitude/long-term water
quality effect on local fish and
aquatic fauna
low magnitude / long-term habitat
disturbance during bridge/ culvert
construction
operation
change to downstream aquatic
biota as a result of water flow
and water quality changes
erosion and sediment control
systems
moderate to high /short-term effect
on downstream aquatic
communities due to water quality
change
low magnitude / long-term species
and community changes due to
riparian and instream habitat
alterations
closure
community / species change
crossing habitat
enhancement
low magnitude / long-term resident
species recovery
An overall residual impact classification is presented in Table 4.3-10;
environmental consequence scores used the screening system described in
Volume A, Section 7.
Table 4.3-11 Residual Impact Classification for Effects on Aquatic Species
Abundance and Health in the Slurry Pipeline Area
Phase
Direction Magnitude
Geographic
Extent
Duration
Reversibility Frequency
Environmental
Consequence
Effect: Community (Habitat) Modification
construction negative
low
local
long-term
no
medium
low
operations
negative
low
local
long-term
no
medium
low
Effect: Change to Fish Health
construction negative
low
local
short-term
yes
high
negligible /
unknown
operations
negative
low
local
long-term
yes
high
negligible /
unknown
Effect: Site Restoration
closure
positive
n/a
n/a
n/a
n/a
n/a
n/a
n/a
= Criteria not ranked for positive impacts.
