The Walvis Bay wetlands can be divided into four main waterbird habitats:
- The lagoon
- Shoreline (Pelican Point and between Walvis Bay and Swakopmund)
- Salt works
The lagoon, a sheltered inlet from the bay, is about 7 km long and 300 m wide at the mouth. The maximum depth at the mouth at low tide is about 2.5 m. The mouth and northern section is where Greater Flamingos may be observed as they feed mainly on invertebrates. The southern section is where Lesser Flamingos are more likely to be found as they feed solely on algae. Most palaearctics can be found on the shoreline and islands. Birds with longer beaks delve deeper and further from shore for invertebrates.
The intertidal mudflats lie between the mouth of the lagoon and the Salt Works pump station. Predominant in this area are various Plovers, Little Stints, etc; these birds are feeding mainly on fly larva. Along the shoreline of the mudflats are Sanderlings, Ruddy Turnstones and Greater Flamingos. There are large areas here that have very high concentrations of invertebrates and here you find longer billed birds.
The western shore, ending at Pelican Point, is sandy and geomorphologically dynamic. The inner (eastern) side of the Pelican Point peninsula is about 6 to 7 km long, with an intertidal area about 800 m wide. A variety of birds may be found feeding here. These are predominantly Greater Flamingos, Ruddy Turnstones and Sanderlings, whilst on the tidal flats are short billed plovers and Curlew Sandpipers. Along this shoreline Eurasian Curlew and African Black Oystercatchers may be observed. The shoreline between Walvis Bay and Swakopmund has the highest linear count of birds in southern Africa (450 birds per km).
Construction of the saltpans began in 1963 and the most recent expansion was in 2000. The total area is approximately 4,400 ha. The main feeders here are the Intra-African and resident birds such as Lesser Flamingos, Cape Teal, Black-winged Stilts, Black-necked Grebes, Avocets African Black Oystercatcher and the White-fronted and Chestnut-banded Plovers which breed here throughout the year.
Gulls and Terns
Hartlaub's Gull, Kelp (Cape) Gull and Grey Headed Gull breed here from January onwards. The near-endemic Damara Tern and the Caspian Tern both breed in the vicinity. Damara Terns breed mainly in cordoned off areas between Walvis Bay and Swakopmund. The Swift Tern, although not breeding here, is found here all year round. It breeds mainly in the Lüderitz area.
About 250,000 terns come here from the northern hemisphere during our summer months as the upwelling from Lüderitz surfaces between Meob and Walvis Bay bringing in krill, zooplankton and phytoplankton. The largest numbers of Terns are normally found down at Sandwich, they feed between Sandwich and Swakopmund and large numbers may be observed along this portion of coast.
Many schools of small fish and krill enter the lagoon during our summer months which, in turn, brings large numbers of terns and fish to feed on them.
There are a number of important issues relating to the conservation of the Walvis Bay Ramsar Site.
Of all anthropogenic impacts, the reduction of intertidal habitat poses the main ongoing threat to the waterbirds at Walvis Bay. This is due to the construction of the saltpans over previously intertidal habitat, the construction of roads, and the reclamation of land for the port and suburbs of the town. Whilst port operations potentially pose a risk from pollutants and the regular dredging of a channel into the port, the risk from these activities has been minimised.
Disturbance reduces the ability of birds to utilise the wetland fully. Disturbances include bird- and cetacean-watchers, angling, canoeing, off-road vehicles etc. Impacts can be minimised by zoning of habitats and restricting activities that can be undertaken in each zone, in combination with other measures such as the provision of hides. While the entire area has been broadly zoned for conservation, proposals have been made for the specific zoning of various activities within the Kuiseb delta area. This zoning will only go ahead once the nature reserve has been proclaimed and the subsequent regulations are in place, and after stakeholders have accepted the lagoon management plan. The proclamation is not intended to exclude members of the public from the area, but rather to work with the public to preserve the wetland. In the zoning proposal, Pelican Point will be zoned for kayaking, motor boats and dolphin and seal viewing. The lagoon mouth will be set aside for powerboat launching, windsurfing, birding and kayaks. No motorised craft will be allowed in the first lagoon area, which is to be reserved for birding, windsurfing and walking. The main lagoon area is to be used for birding and walking only. Non-destructive mari-culture activities, such as oyster farming and the salt works' pumping, will be allowed in the bay, as well as ski-boating, fishing, dolphin viewing and birding. The salt works area is to be designated for salt production, birding and access to Paaltjies. There is also the bird sanctuary zone and the delta zone, where birding, walking, a 4x4 trail and community-based tourism operations will be allocated once the Nature Reserve has been proclaimed.
In the long-term, siltation poses the major natural threat to the existence of the lagoon. There are two sources of sediments: firstly, sand is blown from the dunes of the Namib Sand Sea by the prevailing southwesterly winds and secondly, the prevailing winds generate an inshore current which transports two million m3 of sediment northwards past Pelican Point annually. Up to 200,000 m3 of this is estimated to enter Walvis Bay each year.