Fisheries - Enviro Dynamics Namibia

F I S H E R I E S , M A M M A L S A N D S E A B I R D S S P E C I A L I S T S T U D Y
numerous mammal and bird species will be occasionally found in or near the MLA (Para. 4.3
refers). Most mammal species are naturally inquisitive and certainly, any dredging activity will
attract small marine mammals e.g. dolphins and seals. Larger, mostly migrating mammals are
expected to avoid areas where maritime activity is high (although this does not exclude the
possibility that large mammals will occasional be found in or near the MLA).
Impacts on birds and marine mammals will nevertheless be limited to the actual mining site and
immediate areas (500 m around the dredging location). Disturbance of the substrate is also likely
to result in higher levels of biological activity, increased particulate matter (assumed of poor
nutritional value) in the water column and at the surface. This will alter bird behaviour as they will
be naturally attracted to these areas. The significance of the impact is summarised in Table 8.
Table 8. Table of assessment of Impact 5 summarizing the likely impact of phosphate mining on the
seabirds and mammals around the MLA.
Nature of the
impact
Extent
Duration
Intensity
Probability
Status (+ or -) Negative
Significance (no
mitigation)
Mitigation
Significance (with
mitigation)
Confidence level
Final Report
Namibian Marine Phosphate (Pty) Ltd.
The impact of phosphate mining on seabirds and marine mammals. Mining operations
might result in the displacement and/or redistribution of seabirds and mammals
because of 1) disturbance of the ecosystem and availability of feed and 2) physical
disturbance of the dredgers including noise pollution
MLA - impact on seabirds and mammals is restricted to areas inside the mining licence
area (ML 170) and possibly the surrounding areas including Zone 1
Medium term – The impact on sea birds and mammals will be for the term of the
exploitation. Occasional interaction between the dredging operations and mammals and
seabirds is likely although the actual level cannot be determined without more specific
information on these groups for the MLA and Zone 1. Once mining ceases these groups
will no longer be affected by the presence of the dredger although the alteration of
behaviour of some species due to possible loss of foraging options cannot be
determined.
Minor effects - Trophic disturbances could have an impact on the behaviour of seabirds
and marine mammals. Noise pollution is a consideration for marine mammals whose
acoustic communications may be affected resulting in avoidance of the area. Night
strikes of birds due to deck lights are likely.
Probable - consequences of trophic interaction disturbances and noise pollution is highly
likely.
Medium – Most sea birds and mammal species found in the area will be affected but at a
low level due to the limited extent of the mining operations.
Maintain a bridge watch for large mammal species. Although the dredger will have
limited manoeuvrability a protocol to limit interaction should be followed – in this regard
JNCC guidelines are recommended. Lighting control to minimise night strikes of birds.
Low
Medium - information based on seabirds and mammals was provided by scientific
specialists, however spatial data is limited. Baseline applies to the whole Namibian coast
for most bird and mammal species – confidence relating to impact in the actual MLA is
therefore low.
Page 74