State of the Bay Report 2011-Final.pdf - Anchor Environmental

State of Saldanha Bay & Langebaan Lagoon 2011
Recommendations
Although the available data do not show this, it is quite likely that effluent discharge to the
Bay from this source has tailed off sharply, owing mostly to the fact that pelagic fish stocks (sardine
and anchovy) have moved beyond the reach of fishing vessels stationed in Saldanha Bay (now
centered off Gansbaai). One of the two major fish processing establishments (Premier fishing) shut
down their operations in Saldanha a few years ago but is set to recommence in the near future
again. In spite of this likely reduction in effluent discharge volumes it is strongly recommended that
both the volume and quality of all effluent discharged from fish processing facilities in Saldanha be
monitored, and that the quality of the effluent be made compliant with existing South African
Water Quality Guidelines for the Coast Zone. All of the existing establishments still operate off
exemptions issued under the old 1956 Water Act and need to be made compliant with the new 1998
National Water Act.
12.1.5 Mariculture
Saldanha Bay is the only natural sheltered embayment in South Africa and as a result it is regarded
as the major area for mariculture. A total area of approximately 145 ha has been allocated to seven
mariculture operators within Saldanha Bay. All operators farm mussels and six of the operators also
farm oysters. Abalone, scallops, red bait and seaweed are each cultured on one of the farms. These
farms have been shown to cause organic enrichment and anoxia in sediments under the rafts owing
to contamination by the farmed animals themselves, faeces, and fouling species.
12.1.6 Shipping, ballast water discharges and oil spills
Shipping traffic and ballast water discharges to the Bay are currently monitored by the Port of
Saldanha. Data indicate a steady growth in the numbers of vessels visiting the Bay and a
concomitant increase in the volume of ballast water discharged to the Bay, especially since 2002 (up
by about 75%). Associated with this increase in shipping traffic, is an increase in the incidence and
risk of oil spills, an increased risk of introducing alien species to the Bay, increased volume of trace
metals entering the Bay, and direct disturbance of marine life and sediment in the Bay. Of particular
concern is the potential input of trace metals to the Bay from this source. Trace metal
concentrations in ballast water discharged to Saldanha Bay have in the past (1996), been shown to
exceed South Africa Water Guidelines. Whether this is still the case or not is unknown, given that
the concentrations of these contaminants in ballast water discharges has not been assessed in
recent years. It may well be that measures introduced to minimise risk from alien species’
introduction (such as open ocean ballast water exchange) have gone a long way towards addressing
water quality issues as well.
It is strongly recommended that shipping traffic and ballast water discharges continue to be
monitored in the future and that this be accompanied by a contaminant monitoring programme.
12.1.7 Other development in and around the Bay
There are a range of other development that are planned (e.g. oil and gas terminals), commissioned
and/or are under construction (e.g. reverse osmosis desalination plants) in and around the Bay that
will add pressure on the ecological function and integrity of the system. Potential impacts from
these activities need to be carefully considered and monitored especially in light of the existing
pressures on the Bay which have already caused severe degradation in some areas.
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