By Shirley Bethune, Selma-Penna Utonih, Christopher Malesu and Kevin Roberts, Polytechnic of Namibia
Wetlands of international importance can be given worldwide recognition as ‘Ramsar sites’ to protect these habitats so important for water birds and to ensure their wise and sustainable use. To date, Namibia has four designated Ramsar sites of which three are within the new Namib-Skeleton Coast National Park: the Walvis Bay wetlands, Sandwich Harbour and, shared with South Africa, the Orange River Mouth. Etosha Pan is the fourth. The new park includes several more potential Ramsar sites, such as the Kunene River Mouth, Cape Cross, Swakopmund Saltworks and all our offshore islands.
The late Keith Wearne would have argued convincingly that the Walvis Bay wetland was the most important coastal wetland in Southern Africa and among the top three in Africa. The diversity of habitats in this wetland, with its lagoon, mudflats, shoreline, saltpans and sewage ponds, supports a quarter million wetland birds each spring and anything from–
70 000 to 100 000 birds in winter when the migrants have left. It well meets the Ramsar criteria of having over 1% of the world population of any water bird species. In fact it meets this for 18 species including up to 70% of the world population of Chestnut-banded plovers, 70% of Greater Flamingos, 65% of Lesser Flamingos and 40% of the world’s Black-necked Grebes.
Others argue that Sandwich Harbour, to the south, rivals the importance of the Walvis Bay wetlands. Its shallow lagoon, salt marsh and intertidal mudflats also support a high diversity and sometimes higher numbers of wetlands birds (175 000). In sad contrast the condition of the wetland at the Orange River Mouth has declined since it was proclaimed in the 1980s when over 20 000 birds used to feed, roost and breed there. This decline is attributed to the degradation of the salt marsh habitat by man and has resulted in this site being placed on the Montreux Record, the international list of proclaimed Ramsar sites now threatened by human activity.
To appreciate our coastal wetlands, a group of Nature Conservation students at the Polytechnic each year visit the coast to gain first-hand experience. This is our account of the excursion undertaken at the equinox this year.
We left on our field trip to the coast on the morning of 23 March. Our aim was to gain first-hand understanding of what we were studying in Ecology, Plant and Animal Studies, to see what we had only read and to conduct our own investigations of Coastal Ecosystems, particularly wetlands and rocky shores. We kept busy doing a Raptor Road Count along the way. This was basically identifying, counting and recording the activities of all the raptors we saw and taking note of vegetation changes along our route. We reached the coast at Swakopmund and then headed north for Henties Bay, where we camped at the UNAM Sam Nujoma Research Station.
In the week that followed we were up early in the morning to catch the low tide. We spent late evenings preparing aquaria for our practical identification test and group presentations and watching documentaries on the Namib and the coast. Midweek we explored the Walvis Bay Ramsar site, studied the birds feeding in the lagoon and learnt to appreciate the value of wetlands. The same day we visited the Fisheries and Marine Resources Research Aquarium in Swakopmund, where we saw our coastal fauna up close in preparation of our own fieldwork the next day. We attended guest lectures on current research projects of fisheries and on the running of an aquarium.
The highlight of the trip was familiarising ourselves with the rocky shore and collecting the organisms we had studied in class that we knew only from textbooks. These included black mussels, barnacles, sea anemones, brittle starfish and sea cucumbers. That day we were up at dawn to catch the low spring tide and reached the site in such thick fog that we had difficulty seeing the horizon to do the height measurements for our profile of the shore.
It was also exciting to visit the famous lichen fields at Wlotzkasbaken where we tested their very visible response to water. As we had been to the nearby site where the Trekkopje/Averna mine is constructing the seawater inlet for their desalination plant, we discussed the sensitivity of lichens to disturbance and air pollution. We wondered about the impacts of the desalination plant on them and how the Environmental Impact Assessment of the mine had taken this into account. We found out a few days later when their environmental officer pointed out that the desalination plant was sited slightly south of the lichen fields and fenced off to stop workers walking across the lichens, also that the pipeline would be routed around the lichen field. She explained that any lichens or other desert plants along the pipeline route had been carefully transplanted to an undisturbed area within the mining concession.
All 22 participating students appreciated this opportunity of having the chance to see how marine and desert organisms are adapted to their environment. None of this would have been possible without the support of the Polytechnic of Namibia, our lecturers and driver and without the supplementary sponsorship from Avis via the Namibia Nature Foundation.
This article appeared in the 2009/10 edition of Conservation and the Environment in Namibia.