Page 612 - Atlas Sea Birds Ver1

6 Synopsis

Authors: AB Makhado, A Amaro, RJM Crawford, TR Gottlieb, M Morais, DN Mwaala, L Nghimwatya, M Seakamela, DB Tom, and
M Witteveen

Abstract:
This chapter summarises the conservation status of the four marine turtles, 15 seabirds and solitary seal that breed in the Benguela
upwelling system (BUS) and adjacent areas to its north in Angola and east in South Africa. It briefly reviews factors that have influenced
the conservation status of these species, including harvesting, competition with fisheries for food, altered availability of safe breeding
sites and major causes mortality, such as by-catch in fisheries, oil spills and disease. It notes that there have been long-term changes in
the distributions of several of the species, which include movements away from the centre of the BUS to its boundaries, and that careful
marine spatial planning will need to be coupled with other initiatives to ensure the future survival of the region’s 20 land-breeding, marine
top predators.
Introduction:
This Atlas aimed to collate as many annual records as possible on the breeding of four marine turtle species, 15 seabird species, and a
solitary seal at different localities in the Benguela upwelling system (BUS) in addition to the adjacent coasts of Angola to the north and
South Africa to the east, and briefly to describe each of the sites. It was anticipated that the compilation of breeding records would improve
understanding of long-term trends in the abundance and distributions of these land-breeding species and facilitate up-to-date assessments
of their conservation status within the region, in terms of criteria adopted by the International Union for Conservation of Nature (IUCN
2022). Although preliminary assessments of Red List status were undertaken for each of the 20 species, final appraisals of their global
status will need to be made by the IUCN, and of their regional status by organisations appointed for that purpose by states party to the
Benguela Current Convention. Additionally, it was anticipated that the Atlas would help to identify Important Bird and Biodiversity Areas
(IBAs) used by the different species for breeding.
None of the four species of marine turtle that have bred in Angola or South Africa are endemic to southern Africa. Leatherback Turtles
(Dermochelys coriacea) bred regularly in both Angola and South Africa, whereas nesting by Green (Chelonia mydas) and Olive Ridley
(Lepidochelys olivacea) turtles was largely confined to Angola, and by Loggerhead Turtles (Caretta caretta) to South Africa (Bachoo 2024,
Morais 2024b). The turtles bred contiguously along broad stretches of suitable habitat, within which it was difficult to distinguish discrete
colonies (Bachoo 2024, Morais 2024b). However, in South Africa, Loggerhead Turtles showed a distinct preference for northern beaches
(Bachoo 2024). Although Hawksbill Turtles (Eretmochelys imbricata) are not known to have bred in Angola, its northern shores are an
important nursery and feeding area for the species (Morais 2024b).
Seven of the region’s breeding seabirds are endemic to the BUS: African Penguin (Spheniscus demersus), Cape Gannet (Morus
capensis), Cape Cormorant (Phalacrocorax capensis), Bank Cormorant (P. neglectus), Crowned Cormorant (Microcarbo coronatus),
Hartlaub’s Gull (Chroicocephalus hartlaubii), and Damara Tern (Sternula balaenarum). Two subspecies are also endemic, the local races
of Kelp Gull (Larus dominicanus vetula) and Greater Crested (Swift) Tern (Thalasseus b. bergii), as is the nominate race of Cape Fur
Seal (Arctocephalus p. pusillus). The breeding populations of Leach’s Storm Petrel (Hydrobates leucorhous) and Roseate Tern (Sterna
dougallii) are isolated and discrete from those found elsewhere. The southern African populations of the other four seabirds, Great
White Pelican (Pelecanus onocrotalus), White-breasted Cormorant (P. lucidus), Grey-headed Gull (C. cirrocephalus), and Caspian Tern
(Hydroprogne caspia) are probably, to some extent, distinct from congeners breeding farther north in Africa. These four species also
occupy inland waterbodies and, as discussed in chapters pertaining to them, there is limited interchange of coastal and inland birds. The
Atlas only discusses the coastal components of the populations that occur in Angola, Namibia, and South Africa.

Conservation status Petrel and Cape Gannet as VU, and the other ten seabirds
as Least Concern (LC) (BirdLife International 2023).
The South-West Indian Ocean sub populations of Cape Fur Seal, too, was regarded as Least Concern (LC)
Leatherback and Loggerhead turtles, which include those (Hofmeyr 2015). Analyses reported in this Atlas suggested
that nest in northeast South Africa, are considered Critically that the EN rating should be retained for African Penguin
Endangered (CR) and Near Threatened (NT), respectively and also applied to Damara Tern; that Cape Gannet and
(Bachoo 2024). In Angola, Leatherback Turtles are Bank Cormorant should be regarded as VU; and Cape
regarded as Endangered (EN) and Green, Loggerhead, Cormorant, Crowned Cormorant, and Hartlaub’s Gull as NT
and Olive Ridley turtles as Vulnerable (VU). Globally, (but Cape Cormorant as VU in Namibia and EN in South
Leatherback, Loggerhead, and Olive Ridley turtles are Africa). In that event, all seven seabird species that are
classified as VU, Green Turtles as EN, and Hawksbill endemic to the BUS would be Threatened or NT. Analyses
Turtle, a visitor to northern Angola, as CR (Morais 2024b). in the atlas indicated that, at a regional level, Leach’s Storm
Numbers of Leatherback and Loggerhead turtles breeding Petrel should be CR; Great White Pelican, Caspian Tern,
in South Africa increased after the 1960s, when monitoring and Roseate Tern VU; and White-breasted Cormorant,
commenced, but lately have shown large fluctuations Kelp Gull, Grey-headed Gull, and Greater Crested Tern
(Bachoo 2024). Numbers of Leatherback and Olive Ridley LC. Factors that have influenced the population sizes and
turtles breeding in Angola recently decreased, whereas distributions of seabirds and Cape Fur Seals along the
those of Green Turtle were stable (Morais 2024b). The coasts of Angola, Namibia and South Africa are briefly
main threats to Leatherback and Loggerhead turtles in the reviewed below.
South-West Indian Ocean were direct harvests of eggs and
grown animals and by-catch mortality in mainly longline Harvests
and gill-net fisheries, including those protecting bathing
beaches (Bachoo 2024). From as early as 1500, African Penguins were killed for
In 2023, African Penguin, Cape Cormorant, and Bank food, for fuel to supply ship boilers, and to be rendered
Cormorant were classified by IUCN as EN, Leach’s Storm down for their fat (Randall 1989). In the early 1800s,

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