Page 125 - Atlas Sea Birds Ver1

Orange River Mouth Species and numbers breeding: Five seabirds have bred
Coordinates: 28.62 S; 16.46 E at the ORM. Their numbers are shown on the foregoing
Description: The ORM is one of a few perennial wetlands table.
on the arid western coastline of southern Africa. It covers
an area of about 18 km from the Sir Ernest Oppenheimer Alexander Bay oxidation dams and waterworks
2
Bridge, 10 km upstream, down to the sea, is dominated Coordinates: 28.61 S; 16.48 E
by fresh water and is best described as a delta-type river Description: The Alexander Bay oxidation ponds and wa-
mouth. The mouth is usually only about 50 m wide, may terworks are situated on the outskirts of the town of Alexan-
close due to northward transportation of sand across it and der Bay, which is on the South African side of the Orange
be opened again by increased river flow. There is an exten- River near its mouth. The old oxidation ponds (28.5867 S,
sive saltmarsh on the southern bank near the ocean (Ander- 14.4801 E) were in the estuarine functional zone and used
son et al. 2003). In 1976, Cape Cormorants bred on a large for breeding by Caspian Tern in 1980 and 1981 (Cooper
sandy island about 1 km upstream from the mouth, Kelp et al. 1992). The use of these dams was discontinued and
Gulls on a sandbank adjacent to that and White-breasted new oxidation ponds were built between 2011 and 2013, at
Cormorants on trees growing on sandbanks, also about 1 a higher location (28.5837 S, 16.4851 E). The old oxidation
km from the mouth (Frost and Johnson 1977). The ORM ponds are now just earth dams/channels in the riverbed,
met several criteria required for classification as a Wetland but during flooding islands form that provide breeding sites.
of International Importance under the Ramsar Convention Hartlaub Gulls bred at the old oxidation ponds in the winter
and was so designated by South Africa in 1991 and Na- of 2018. The oxidation ponds at the new waterworks are
mibia in 1995 (Anderson et al. 2003). In the latter part of lined with plastic and enclosed by a mesh fence. 26 pairs
the twentieth century, the ORM was subjected to several of Hartlaub’s Gull bred on bare ground between the ponds
negative impacts that included: altered river flow and artifi- in February 2018.
cial opening of the mouth, which led to reduced flooding of Conservation status: It is not protected. The fence dis-
low-lying areas; use of lands for agriculture; and construc- courages human access and may deter mammals such as
tion of a levee to protect those lands and of a road embank- feral cats and dogs from accessing the site.
ment to provide access to the beach, which isolated and Species and numbers breeding: These are shown on the
led to severe degradation of the salt marsh (Anderson et al. following table.
2003). In the 1980s, the estuary lost 276 ha of its wetland
area near the mouth as a result of such poor management Year Hartlaub's Gull Caspian Tern
practices (Bornman and Adams 2010). These changes and
increased disturbance by humans reduced the availability 1980 1
of suitable roosting and nesting sites for birds (Anderson et 1981 2
al. 2003) and contributed to the cessation of breeding in the 2017 0
ORM by all five seabirds that formerly nested there, Cape
and White-breasted Cormorants, Kelp and Hartlaub’s Gulls 2018 26 0
and Caspian Terns (Crawford et al. 2018). 2019 0 0
Conservation status: The ORM is not protected by legis-
lation but is a Ramsar wetland. It is accessible to the public. Alexander Bay diggings
Coordinates: 28.63 S; 16.50 E
Description: Open gravel plains south of Alexander Bay

Year Cape Cormorant White- breasted Cormorant Kelp Gull Hartlaub's Gull Caspian Tern town where Damara Terns formerly bred. They are in a
restricted area, mined for diamonds by Alexkor, a wholly
state-owned South African diamond mining company that
falls under the Department of Public Enterprises, in a joint
1956 54 39 venture with the Richtersveld Mining Company, which is
1976 7873 10 150 owned by the Richtersveld community, and are not acces-
1977 √ √ sible to the general public. However, in 2018 the area was
subject to substantial disturbance through mining activities.
1978 7 62 Conservation status: The locality is not protected but falls
1979 √ within the Alexkor mining concession, which has restricted
1980 75 12 access.
1981 250 50 300 Species and numbers breeding: Records of breeding
and non-breeding by Damara Terns are shown on the fol-
1985 42 lowing table.
1986 √
Year Damara Tern
1989 700
2011 0 0 1995 √
2007 √
2012 0 0
2015 0
2017 0 0 0
2018 0 0 0 0 0 2016 0
2019 0 0 2017 0
2018 0

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