State of the Bay Report 2010-Final - Anchor Environmental

Anchor Environmental
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/lagoon.
Several dredge 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), 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 ore jetty
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
has been constructed at the Ore Terminal in Big Bay which is set to start discharging effluent into the
Bay in the near future and the refurbishment and expansion of the small craft harbour at
Salamander Bay in Langebaan Lagoon. The possibility of establishing of 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 jetty 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 is no longer operational but there is an
indication that this factory may be brought back into commission soon. Sea Harvest discharges fresh
fish processing effluent into the sea daily, with historical monthly discharges ranging between 50
000 to 90 000 kl. Fish factory effluents contain large quantities of organic wastes, which accumulate
in Small Bay and lead to significant degradation of the marine environment. There is currently one
main mariculture operation in Small Bay (Blue Bay Aquafarm which farms mussels) and several areas
have been earmarked for future mariculture developments. Elevated concentrations of organic
State of the Bay 2010: Saldanha Bay and Langebaan Lagoon 22