SURF’S UP! …uh oh…
Text Edward Jenkins Photo Paul van Schalkwyk
In 1971, concerns for the conservation and wise use of wetlands worldwide led to an international treaty designed to support national action and international cooperation. To date, 167 countries have joined the Convention on Wetlands of International Importance (the Ramsar Convention). Namibia has identified five Ramsar sites, including Sandwich Harbour, thus designated in 1995.
Arguably the least accessible of Namibia’s five Ramsar sites, Sandwich Harbour – located approximately 55 km south of the Municipality of Walvis Bay – is a world-class destination for birders, an off-road driving adventure for 4X4 enthusiasts, and a place of interest for those with a penchant for history. Sadly, it can also be a place to turn an expensive four-wheel-drive vehicle into a submarine for those who choose not to pay close attention to the tide charts.
The origins of the name Sandwich Harbour are obscure. More a lagoon than a harbour, some attribute the name to a British whaler, The Sandwich, which visited around 1789, and whose captain may have made the first accurate maps of the area. Others claim the name describes the ‘sandwiching’ effect of an area of fresh water caught between the dunes of the Namib sand sea and the tides of the South Atlantic Ocean. Finally, some believe it is a derivation of the German word, sandfische, a type of shark found in the area.
Regardless of the name, the key to the profusion of life here is a large aquifer bubbling fresh water through the sand and creating the northern freshwater wetland. To the south, tidal influences form enormous mud flats, and to the east, the Namib dune sea reaches the ocean, offering a measure of protection from human encroachment, and some spectacular photo opportunities.
Today, Sandwich Harbour is entirely within the Namib-Naukluft Park, with a marine protected area offshore. Considered one of Southern Africa’s most important wetlands for both migratory and resident birds, an estimated 50,000 birds may be present in the summer, and 20,000 in the winter. In 1991, a record 115 species were recorded, including 179,000 wading birds. (In 2013, Sandwich Harbour recorded 51,500 greater and 10,900 lesser flamingos, in a year when a lack of rain rendered Etosha unpopular as a breeding site.)
The Sandwich Harbour environment is the home for a number of red-data bird species, including the Damara tern and chestnut-banded plover, as well as pelicans, avocets, turnstones, and dune larks. Peregrine falcons, southern pale chanting goshawks and black-chested snake-eagles may also be present.
Many archaeological sites in the area demonstrate Sandwich Harbour’s long involvement in human endeavours. The earliest habitants may have been the Strandlopers – a nomadic beachcombing people believed to be the direct ancestors of the Topnaar – who remain in the area today. When American and British whaling ships discovered the freshwater supply that was available there in the early 18th century, trade began with the Topnaar, who bartered cattle for beads and other goods. In time, fishing, guano collection, sealing and even shark-oil extraction industries grew up in the area, where today only rusted relics remain.
Studies in recent years have shown that the northern freshwater wetlands have decreased dramatically in size. Twenty years ago, the freshwater lagoon was approximately one kilometre across; today, it is only about 200 metres. The aquifer appears to be fed from the ephemeral Kuiseb River, and as the demand for fresh water increases for growing communities such as in Walvis Bay and Sossusvlei, less water is available to replenish the aquifer. Some scientists believe that the lower numbers of bird species found during annual bird counts in recent years are a direct result of these changes, since the freshwater lagoon traditionally hosts a much higher diversity of species, while the mud flats host many thousands of other birds, primarily from wading species.
The wise allocation of precious water resources is a constant struggle for the government of an arid land such as Namibia. With careful monitoring and management, and with the support and assistance of global experts on water management available through the Ramsar Convention, administrators will have the tools they need to maintain this internationally important wetland for future generations of birders – and potential submariners – to enjoy…
RAMSAR SITES IN NAMIBIA
Namibia currently hosts five designated Wetlands of International Importance as prescribed by the Ramsar Convention:
- Etosha Pan, Lake Oponono and the Cuvelai drainage system (central-northern Namibia)
- Sandwich Harbour (Atlantic coast, approximately 55 km south of Walvis Bay)
- Walvis Bay Lagoon (Atlantic coast, immediately south of the Municipality of Walvis Bay)
- Orange River Mouth (Namibia/South Africa border, on the Atlantic coast)
- Bwabwata-Okavango (Lower Okavango River and adjacent marshes/flood plains)
Generally, wetlands are areas where water is the primary factor controlling the environment and the associated plant and animal life. They occur where the water table is at or near the surface of the land, or where the land is covered by water.
Five major wetland types are generally recognised:
- Marine (coastal wetlands including coastal lagoons, rocky shores, and coral reefs)
- Estuarine (including deltas, tidal marshes, and mangrove swamps)
- Lacustrine (wetlands associated with lakes)
- Riverine (wetlands along rivers and streams)
- Palustrine (meaning ‘marshy’– marshes, swamps and bogs)
The Ramsar Convention, recognising man’s influence on the environment, has simplified wetland definitions into three categories:
- Marine and Coastal Wetlands
- Inland Wetlands
- Man-made Wetlands, such as fish and shrimp ponds, farm ponds, irrigated agricultural land, saltpans, reservoirs, gravel pits, sewage farms and canals.
The Shifting Sands of Sandwich Harbour
By Hu Berry
During the 1970s the northern section of Sandwich Harbour was an extensive system of tidal mudflats, which drained brackish and fresh water pools. At its widest point the beach was about one kilometre from the base of the dunes.
Twenty years later, 1992, the sea has pushed back the beach towards the dunes, covering large portions of the vegetation with a blanket of wave-washed sand. Only a narrow channel still drains the pools at the far (southern) end.
By 1997 the beach has closed against the dunes in the south and no tidal flow is possible. The vegetation is dying from increased salinity and the beach broadens as it moves closer to the dunes.