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Site description (2001 baseline):
Site location and context
The Lüderitz Bay island complex consists of four coastal islands, all situated within one kilometre of the shore. The rocky shoreline, including Lüderitz fishing harbour, is included within the IBA. Halifax Island (3 ha) is located at the south end of Guano Bay near Diaz Point, a promontory at the western entrance of Lüderitz Bay, and one of the first landfalls of Portuguese explorers in the 1400s. The whole area lies within the intense upwelling cell off the Lüderitz coastline, creating a node of high marine productivity resulting in large congregations of seabirds. The other three islands, Penguin (36 ha), Seal (44 ha) and Flamingo, lie to the east of Halifax, within Lüderitz Bay. The islands hold some abandoned guano-scrapers’ buildings. They support no vegetation other than subtidal kelp and other seaweed on their shores.
See Box for key species. The island complex regularly supports over 10,000 seabirds. Halifax Island is an important coastal seabird breeding island; it supports over 2,000 breeding seabirds, including important numbers of breeding
Spheniscus demersus (c.400 pairs),
Sterna bergii and
Phalacrocorax coronatus. Penguin and Seal islands are utilized mostly for roosting, but
Phalacrocorax coronatus,
P. neglectus,
P. capensis (2,000 pairs) and
P. carbo (20 pairs) all breed on Penguin Island. The latter also holds large numbers of
Haematopus moquini (possibly 20% of the world population), which probably breed, and roosting
Sterna balaenarum. Seal Island is important for
Phalacrocorax coronatus, as it holds some 3% of the world population. It also holds many pairs of
Larus dominicanus, which occasionally depredate cormorant eggs when the latter are disturbed.
On the adjacent mainland, the harbour supports dense nesting populations of
Larus hartlaubii and
Sterna bergii. In 1994, at least 2,470 pairs of
S. bergii (40% of the southern African population) nested successfully there and on the rocky promontory called Shark Island. The shoreline is completely rocky and the Lüderitz peninsula, excluding the islands, holds about 14,000 shorebirds. At 30 birds/km it is locally dense, but supports a lower linear density than shores farther north in central Namibia.
Non-bird biodiversity: Among the cetaceans that occur, Cephalorhynchus heavisidii (DD), Lagenorhynchos obscurus (DD) and Tursiops truncatus (DD) are frequently seen, while Megaptera novaeangliae (VU) and Eubalaena australis (LR/cd) are rarer.
Pressure/threats to key biodiversity
All of the near-shore islands on the Namibian coast were managed by Cape Nature Conservation as nature reserves when they were under South African rule. Now, under Namibian law, they no longer carry the same status, but fall under the jurisdiction of the Ministry of Fisheries and Marine Resources who man three of them. Previously, all the islands held more breeding birds than at present; their proximity to the mainland, and Namibia’s only other fishing port, resulted in intense exploitation by humans, probably even before the precipitous decline of
Spheniscus demersus in the 19th and 20th centuries. Three seabird species,
Spheniscus demersus,
Morus capensis and
Phalacrocorax capensis, have suffered serious population declines in the last 30 years, mostly because of overfishing of surface-shoaling fish, such as
Sardinops sagax, their main food source. These birds are also renowned for their guano, which has been harvested for over 100 years for fertilizer, resulting in disturbance during breeding, which compounds their population declines. This has affected
Spheniscus demersus most severely, as it prefers to burrow into the guano. Large-scale guano harvesting removed the penguins’ cover and forced them to breed in the open, exposing their chicks and eggs to increased predation by gulls and seals, excessive heat during the day and other hazards.
Conservation measures, including reduced guano-scraping, currently ensure that these birds are not disturbed during the main breeding season, but some disturbance always occurs as the birds breed all year-round. Egg-collecting persisted well into the 1970s on some of these islands, and may still occur at low levels. Further conservation problems for coastal seabirds include a growing population of seals
Arctocephalus pusilla, which has been steadily increasing in number along the Namibian coast after a period of severe exploitation during the 1800s.
Arctocephalus pusilla often disrupt and displace breeding seabirds on islands. They are physically discouraged from hauling out on the three manned islands further south.
Phalacrocorax neglectus, which forage primarily on
Sufflogobius bibarbatus and
Jasus lalandi, have recently suffered a global decline of 34%. The decline has been attributed to a reduction in food abundance and displacement by seals. Appropriate management, permitting stock recovery of their primary prey-species, may lead to an improvement in population levels of
Phalacrocorax neglectus.Onshore, harbour pollution appears minimal but disturbance to breeding gulls and terns in the harbour itself by humans and dogs and cats has been severe. Attempts to control it have met with some success, but disturbance will increase as the harbour is renovated.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Lüderitz Bay islands (Namibia). Downloaded from
https://datazone.birdlife.org/site/factsheet/lüderitz-bay-islands-iba-namibia on 23/12/2024.
