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

State of Saldanha Bay & Langebaan Lagoon 2011
Executive Summary
Island causeway and the iron ore terminal, the establishment of a three small craft harbours,
mariculture farms and several fish processing factories, while extensive industrial and residential
development have become established around the periphery of the bay. Anthropogenic pollutants
and wastes find their way into the bay from a range of activities and developments within the study
area. These include dredging and port expansion, port activities, shipping, ballast water discharges
and oil spills, municipal (sewage) and household discharges, discharge from fish processing factories,
biological waste associated with mariculture and storm water runoff.
Coastal developments in Langebaan and Saldanha extend right to the waters edge. The lack
of a development setback zone or coastal buffer places stress on the marine environment due to
increased risk of erosion, trampling and habitat loss as well as allowing large volumes of storm water
runoff to enter the bay and lagoon.
Several dredging events have occurred in Saldanha Bay to facilitate the development of the
port, namely the construction of the Marcus Island Causeway (1973), General Maintenance Quay
and Rock Quay (1974-1976), Multi-Purpose Terminal (1980) and the Small Craft Harbour (1984). The
Multi-Purpose Terminal was extended in 1997/1998 which required further dredging. Maintenance
dredging was performed at the Mossgas Terminal and the Multi-Purpose Terminal at the end of
2007. Additional dredging was conducted between Caisson 3 and 4 on the Saldanha side of Iron Ore
Terminal in 2009/10 when 7 300 m 3 of material was removed from an area of approximately 3 000
m 2 in extent at the end of the causeway. Transnet has also proposed a Phase 2 expansion of the Iron
Ore Terminal (Big Bay side) to increase its holding capacity, which would require extensive dredging
and marine blasting. This proposal is currently on hold, pending improvements in the international
iron ore market. Other development in and around the Bay include a reverse-osmosis desalination
plant which has been constructed at the Iron Ore Terminal in Big Bay and the refurbishment and
expansion of the small craft harbour at Salamander Bay in Langebaan Lagoon. The possibility of
establishing an Industrial Development Zone along the north shore of the bay and a new LPG gas
terminal in the bay are also under consideration.
Human induced changes within Saldanha Bay (mostly changes in current circulation and
wave activity) have also contributed to the erosion of Langebaan beach and Paradise beach. In
order to mitigate this and to alter wave dynamics and reduce erosion, groynes have been
constructed at the mouth of Langebaan Lagoon, which required dredging of marine sands. Dredging
of the seabed has significantly altered sediment composition and had a devastating effect on the
Saldanha Bay marine environment in the past, principally through the loss of benthic species. The
impacts of dredging are mostly observed in the vicinity of the iron ore terminal and within Small Bay.
Storm water enters Saldanha Bay/Langebaan Lagoon via multiple storm water drains and
tarred surfaces. Storm water is a major source of non-point pollutants to the bay and typically
contains contaminants such as metals, bacteria, fertilizers (nutrients), hydrocarbons, plastics,
pesticides and solvents. Increased volumes of storm water runoff (as a result of development) are
associated with degradation of aquatic environments. Studies conducted by the CSIR indicate that
the concentrations of several contaminants (nitrate, ammonia, metals and faecal coliforms) in
Saldanha Bay storm water runoff are well above water quality guidelines.
Historically, two fish processing factories have discharged effluent into Small Bay, namely
Southern Seas Fishing and Sea Harvest. The former ceased operations a few years ago but is likely to
be recommissioned again soon. Sea Harvest discharges approximately 35 000 m 3 of effluent from
their fresh fish processing effluent into Small Bay each month. This effluent contains significant
quantities of organic material (suspended solids, ammonia and other nitrogenous compounds)
which stimulate primary production (algal growth), consume oxygen, and can lead to deterioration
in water quality in the Bay.
Saldanha Bay is the only natural sheltered embayment in South Africa and as a result it is
regarded as the major area for mariculture. There are currently seven mariculture operators that
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