State of the Bay Report 2010-Final - Anchor Environmental

Anchor Environmental
changes that probably occurred in the system would have taken place at the same time that the
changes in benthos and eelgrass took place (i.e. 1970s-1980s), and as no fish sampling took place
over this period, these are not reflected in the available data which only exists from the late 1980’s.
Fish sampling surveys should be conducted annually at the same sites selected during the
2005 study for the next two years but could then be reduced in frequency to once every five years
thereafter. This sampling should be confined to the same seasonal period each year for comparative
purposes. Additional data on daily catch records from anglers (West Coast National Park and fishing
clubs) is now being collected by Marine and Coastal Management. This initiative should be strongly
supported as it will provide invaluable information that will contribute to an improved
understanding of the overall health of fish populations in the Bay.
13.7 Birds
An alarming decrease in the abundance of both resident and migrant waders utilising
Langebaan Lagoon is evident over the past decade and is believed to be a function of increased
human utilisation of the area and possible reduction in available food. Similar declines are evident in
some bird species breeding on the offshore islands in the Bay. This is believed to be a function of
reductions in their food supply (largely pelagic fish e.g. pilchard) outside of the Bay and human
disturbance within the Bay. Encouraging increases in numbers of African Black Oystercatchers have
been observed on some of the islands in the Bay and is believed to be related to the proliferation of
alien mussels on rocky shores in the area, which constitute an important food source for these birds.
Populations of key bird species are currently monitored annually on the offshore islands
within the Saldanha Bay area, whilst bird populations in Langebaan Lagoon are monitored twice per
annum. These bird counts are conducted as part of an ongoing monitoring programme, managed by
the Avian Demography Unit of the University of Cape Town and Oceans and Coasts (Department of
Environmental Affairs). The data from these surveys should be regularly obtained from these
organisations and examined on an annual basis.
13.8 Summary of environmental monitoring requirements
In summary, the environmental monitoring currently implemented in Saldanha Bay and
Langebaan Lagoon (e.g. sediment, benthic macrofauna and birds) should continue with some small
adjustments or additions, however, monitoring of other environmental parameters that are not
currently assessed on a regular basis (e.g. temperature, oxygen, rocky intertidal and fish
populations) require structured, maintained monitoring to be implemented.
State of the Bay 2010: Saldanha Bay and Langebaan Lagoon 263