Page 614 - Atlas Sea Birds Ver1

Human refuse and modification of the environment, e.g. fed significantly further from the survey vessel when it was
construction of artificial water bodies, made alternative in operation, and increased their foraging effort (Pichegru
sources of food available to some of South Africa’s et al. 2017). Attempts were made to minimise many of
seabirds, including Great White Pelican, White-breasted these impacts. For example, in 2000, following that year’s
Cormorant, and gulls. They were thought to have aided Treasure oil spill, > 41,000 African Penguins, oiled, at risk
increases in numbers of pelicans (Crawford et al. 1995) of being oiled, or orphaned, were rescued at Dassen and
and Kelp Gulls (Steele 1992, Crawford et al. 2009) in South Robben islands, and most were successfully returned to
Africa’s Western Cape. the wild (Crawford et al. 2000).

Safe breeding habitat Quo vadis?

Historically, islands in the BUS and adjacent areas provided In spite of substantial efforts to conserve land-breeding
safe breeding habitat for many of the region’s seabirds and marine predators around the coasts of Angola, Namibia,
its seal. However, the joining of Shark, Bird (Lambert’s and South Africa, it is clear from recent decreases of two
Bay), and Marcus islands to the mainland allowed access turtle species in Angola and the unfavourable conservation
to them by terrestrial predators. Feral cats (Felis catus) status of all seven of the Benguela’s endemic seabirds that
were introduced to Dassen and Robben islands, and more needs to be done. In particular, there is need to ensure
remain at the latter, which also has been substantially adequate forage resources for seabirds that compete with
modified for human use. At other islands historical deposits fisheries for prey, to protect important mainland breeding
of guano were removed. As most of the islands were rocky, habitats of seabirds, and to take every effort to safeguard
this meant that penguins were unable to excavate burrows breeding ‘super sites’ from potentially catastrophic events,
for nests, which ameliorate heat and cold and protect eggs such as oil spills, disease, and displacements by other
and nestlings from aerial predators (Frost et al. 1976). animals.
Instead, they had to nest on the surface, which negated With regard to the first of these objectives, in 2020 a
these benefits and, similarly to other surface-nesting birds, Benguela Current Forage Fish Workshop, organised by
meant that penguins could be displaced from their breeding the African-Eurasian Migratory Waterbird Agreement
areas by the larger seals (Crawford et al. 1989). (AEWA), in collaboration with the Benguela Current
Some former mainland nesting localities, including Convention and BirdLife South Africa, recommended inter
estuaries and coasts, have been rendered unsuitable for alia that tools be developed to increase the availability of
breeding by human modifications (e.g. Anderson et al. sufficient forage for threatened, endemic Benguela seabird
2003, Crawford et al. 2018), mining, and development, species, such as setting ecosystem thresholds, closing
which, for example,caused the extinction of an important key seabird foraging areas to fishing, and creating suitable
Damara Tern colony at Dolphin Beach (Braby 2011). Of seabird breeding habitat within contracted or altered
71 localities known to have been used for breeding by distributions of forage fish species (AEWA 2020). For a
Damara Terns, 70 were on the mainland, so Damara Terns summary of ecosystem thresholds derived for seabirds,
are especially susceptible to mainland threats. Islands in with particular reference to the BUS, see Crawford et al.
estuaries may naturally become unsuitable for breeding by (2022). It is hoped that information collated in this Atlas
floods that swamp them or droughts that connect them to will assist coastal and marine spatial planning through the
the mainland (e.g. Fox et al. 2024). identification of key seabird breeding habitats that need to
Guano platforms provided additional breeding habitat be protected from the threats identified above, e.g. through
for Cape and White-breasted cormorants and pelicans fishing closures and prohibition of ship-to-ship bunkering
in Namibia to the north of Walvis Bay (Crawford 2007). in their vicinity, and routing of shipping away from their
Artificial nests were deployed at some islands in attempts proximity. Substantial information already exists on the at-
to improve breeding habitat for African Penguins (Pichegru sea distributions of several of the land-breeding, marine
2012). A headland on South Africa’s south coast, where predators of Angola, Namibia, and South Africa (e.g.Green
penguins bred for several years in the 2000s but stopped et al. 2015, Robinson et al. 2018, Carpenter-Kling et al.
because of losses to terrestrial carnivores, was fenced 2022). However, collation of published and unpublished
off and recolonised by a pair of penguins in 2022 (Hagen information on such distributions will assist with the
2022, Dyer et al. 2024). identification of important transit and feeding areas of these
animals.
Other threats
References
Other threats to land-breeding, marine vertebrates of
the BUS and adjacent areas include by-catch mortality AEWA. 2020. Benguela Current Forage Fish Workshop
in fisheries (da Rocha et al. 2021) and predation or recommendations, 4 pp.
disturbance of eggs, chicks, fledglings, and adults at and Anderson MD, Kolberg H, Anderson PC, Dini J, Abrahams A.
around colonies by pelicans, gulls, seals, sharks, feral 2003. Waterbird populations at the Orange River mouth from
and mainland carnivores, and humans (Whittington et al. 1980–2001: a reassessment of its Ramsar status. Ostrich
1996, Johnson et al. 2006, Makhado et al. 2006, 2013, 74: 159–172.
Mwema et al. 2010, Pichegru 2012). Additionally, oil spills, Bachoo S. 2024. Population trends and conservation status of sea
diseases, and severe weather conditions have caused turtles in northern KwaZulu-Natal. This volume.
substantial mortality of seabirds, or reduced their breeding BirdLife International. 2023. IUCN Red List for birds. Downloaded
from http://www.birdlife.org on 04 January 2023.
success (Waller and Underhill 2007, Wolfaardt et al. 2009, Braby J. 2011. The biology and conservation of the Damara Tern in
Sherley et al. 2012). Penguins showed a strong avoidance Namibia. PhD thesis. University of Cape Town, South Africa,
of their preferred foraging areas during seismic activities, 233 pp.

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