Environmental Assessment
Volume E-3.9
Tailings Facility
Oceanography
Ambatovy Project
114
January 2006
Impact 2 - Effect of Outfall Effluent on Fisheries
Moderate increases in TSS can be advantageous to benthic biota and
planktivorous fish provided it has a high organic content and is nutritious as a
food source. However, the constituents of the effluent discharge indicate very
low organic contents, and it is therefore not likely to benefit the benthic filter
feeders or planktivorous fish in the area. The only fisheries operating within the
area under consideration are the small scale commercial operators and artisinal
fishers who occasionally venture out to sea from the ivondro estuary. The line
fishery will operates on deeper reefs in the area, none of which are found around
the proposed outfall location.
Mitigation
Monitoring of catches within the various fisheries will allow for trends to be
identified. Periodic analysis of samples of fish and other marine animal tissue for
levels of effluent components will be undertaken as a method of determining the
presence of any long-term cumulative effects.
Residual Impact
A change in marine biota may result in a severe to moderate impact in the local
fishery in the long-term on a local scale. The overall environmental consequence
of this impact is moderate.
Issue 5 – Impact of the Outfall on Tourism
Impact 1 – Reduction in Tourism Potential
The naturally high levels of turbidity mean that any addition due to the outfall is
unlikely to be noticed by anyone using the beach facilities. Similarly, the rapid
dilution of the effluent components should preclude any adverse effects on beach
users or swimmers. Tourism is not a major industry in the immediate outfall
area, however, visitors do make use of the beaches on occasion. There may be
concern that effluent levels and high turbidity would negatively affect this trade.
Mitigation
Consultation will be conducted with the tourist operators. Disclosure of the
pipeline, its purpose and contents, along with monitoring results, will be offered
to demonstrate that none of those pose a threat to human life and well being.
Residual Impact
The overall impact of the outfall effluent on the tourism industry will be
moderate in the long-term in a local area. The overall environmental
consequence is regarded as being low.
