Environmental Assessment
Volume B-4.3
Mine
Fish and Aquatic Resources
Ambatovy Project
242
January 2006
Table 4.3-1 and Figure 4.3-1). A majority of the natural, undisturbed, sites
occurred in the headwater sites of watersheds draining the mine area (1
st
, 2
nd
and
3
rd
order streams).
Within the Torotorofotsy Wetlands (seven sites) aquatic habitats generally
exhibited significant disturbance and loss of natural ecosystem function (IHIA
Classes D, E and F). Only two sites on small inflowing tributaries displayed
natural, unmodified, conditions.
Table 4.3-1 Habitat Characteristics of Stream Sample Sites in the Mine Local
Study Area
Site
IHIA
Class
(a)
Habitat Description
QESF101
T
D
Largely modified, loss of natural habitat, biota and ecosystem function. Major
threats are bed modification due to deforestation and exotic fish species.
QESF103
T
D
Largely modified; similar to preceding site.
QESF104
T
A
Unmodified habitat, minimal deforestation in surrounding catchment. Some
riparian invasion with exotic aquatic plants.
QESF105
A
Unmodified habitat, minimal deforestation in surrounding catchment.
QESF106
B
Largely unmodified. Minor changes in natural habitat and biota but basic
ecosystem functions unchanged.
QESF107
F
Critically modified. Bed and channel modification due to conversion of adjacent
wetland into paddy rice fields. Exotic plant growth in stream channel.
QESF108
E
Extensively modified with loss of natural biota and ecosystem function.
QESF109
A
Unmodified primary forest area.
QESF110
A
Unmodified primary forest area.
QESF111
T
F
Critically modified. Major impacts are deforestation in catchment and creation of
wooden weir across stream resulting in increased turbidity and sedimentation.
QESF112
T
C
Moderately modified. Loss of natural habitat and biota, but basic ecosystem
functions remain predominantly unchanged (moderate size river site;
Torotorofotsy Wetlands outflow).
QESF115
D
Large-scale loss of natural habitat, biota and ecosystem function (Mangoro River;
large river site).
QESF117
A
Unmodified habitat. Some riparian zone invasion with exotic plants.
QESF123
T
A
Unmodified, natural habitat.
QESF124
T
E
Extensively modified with loss of natural biota and ecosystem function.
QESF125
E
Extensive modification of bed, channel, flow regime and presence of exotic fish
species. Indigenous vegetation entirely replaced by exotics (large stream site).
EPH1
n/a
Located in a moderately to highly degraded area.
EPH2
A
Unmodified habitat. No evidence of human impact.
EPH3
A
Unmodified habitat. Limited human impact.
(a)
Based on the IHIA model (Kemper 1999).
T Torotorofotsy Wetlands tributary.
n/a Not applicable.
