Environmental Assessment
Volume E-3.9
Tailings Facility
Oceanography
Ambatovy Project
116
January 2006
Table 3.9-4 Operational Phase Impacts on the Marine Environment
Without Mitigation
With Mitigation
Issue/Impact
Risk
Temporal
Spatial
Cert.
Magnitude Magnitude Environmental
Consequence
Issue 3: Specific Impacts On The Near Shore Environment
Impact 1: Effect of effluent constituents
on marine biota including corals
will occur long-term localized
possible very severe moderately
severe
low
Issue 4: Impact On The Fisheries Resource
Impact 1: Reduction of gillnet fishery
area
will occur long-term localized
possible moderately
severe
severe
low
Impact 2: Effect of the outfall effluent on
fisheries
will occur long-term localized
possible moderately
severe
moderate
moderate
Issue 5: The Impact Of The Outfall On Tourism
Impact 1: Impacts associated with
reduction in tourism
will occur long-term localized
possible moderately
severe
slight
low
3.9.5
Conclusions
There are limited opportunities to add value from an environmental perspective
that will arise from the installation and operation of the marine outfall. Indirect
benefits will obviously accrue from the plant and tailings facilities.
The operation of a marine outfall will impact on the marine environment. Due to
the naturally occurring turbidity levels, increased turbidity and smothering are
unlikely to be significant risks. In addition, levels of contaminants in the effluent
and the dilution factors involved mean that the risk of damage to sensitive coral
reef habitats is unlikely to be significant, and should not prevent the project from
continuing. It is anticipated, however, that public opinion, in particular from the
fishing industry may be an issue (Volume A, Section 6).
This assessment, together with baseline data in Volume I, Appendix 10.1,
Attachment 2, comprised a snapshot of the nature and condition of the
Toamasina reefs to establish the impacts of the proposed marine disposal of
effluent from the nickel processing plant is a viable option. A fatal flaw is
unlikely, however further quantitative data gathering will be implemented both
from a design perspective and to supplement environmental baseline information.
The precautionary approach has thus been followed due to the lack of temporal,
spatial coverage and accuracy of physical and chemical oceanographic data
describing the site specific conditions.
Nevertheless, one can conclude that the Toamasina reefs are extensive but
naturally stressed and are relatively poor in biodiversity. Their condition appears
