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

Number of breeding pairs
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
State of Saldanha Bay & Langebaan Lagoon 2011
Birds
600
500
400
Total
Malgas
Jutten
Marcus
African Black Oystercatcher (3 Islands only)
300
200
100
0
Figure 10.10. Trend in breeding population of African Black Oystercatchers older than 1 year, on Marcus,
Malgas and Jutten Islands. (Data source: Douglas Loewenthal, Oystercatcher Conservation
Programme).
Year
10.3 Birds of Langebaan Lagoon
10.3.1 National importance of Langebaan Lagoon for birds
Langebaan Lagoon supports an average of about 50 000 waterbirds during summer and about
18 000 during winter. Fifty-five species of waterbirds are regularly recorded at Langebaan Lagoon.
About two thirds of the waterbird species are waders, of which 18 species are regular migrants from
the Palaearctic region of Eurasia; these make up 87% of the summer wader population by numbers.
Important non-waders which utilise the system are Kelp and Hartlaub's Gulls, Greater Flamingo,
Sacred Ibis and Common Tern. Resident waterbird species which utilise the rocky and sandy
coastlines include the African Black Oystercatcher and the White-fronted Plover, both of which
breed in the area.
The thousands of migratory waders visit Langebaan Lagoon during the austral summer
making it the most important ‘wintering’ area for these birds in South Africa (Underhill 1987). Since
Langebaan Lagoon regularly supports over 20 000 waders it is recognised as an internationally
important site under the Ramsar Convention on Wetlands of International Importance, to which
South Africa is a signatory. With regard to density and biomass of waders, Langebaan Lagoon
compares favourably to other internationally important coastal wetlands in West Africa and Europe.
The true importance of Langebaan Lagoon for waders cannot be assessed without recourse
to a comparison with wader populations at other wetlands in southern Africa. During the summer of
1976 to 1977, the wader populations at all coastal wetlands in the south-western Cape were
counted (Siegfried 1977). The total population was estimated at 119 000 birds of which 37 000
occurred at Langebaan. Only one other coastal wetland, the Berg River estuary, contained more
than 10 000 waders. Thus, Langebaan Lagoon held approximately one third of all the waders in the
south-western Cape (Siegfried 1977). Studies were extended to Namibia (then South West Africa) in
the summer of 1976-77. Walvis Bay Lagoon contained up to 29 000 waders and Sandvis had
approximately 12 000 waders. Therefore, it was determined that Langebaan Lagoon was the most
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