South Africa recently celebrated National Marine Week. Estuaries, due to their saline and freshwater properties, was a prominent focus of the national campaign. It is particularly the intricate nature of estuaries, coastal waterbodies permanently or periodically open to the ocean, that is calling for better protection. South Africa has a total of 259 estuaries with estuary locations relating directly to river locations.
Great Brak Estuary, Southern Cape, South Africa
As seen in the above photograph, an estuary system is found where freshwater from a river, runs into the ocean. Yet the nature of estuaries differs and this point of opening up to the ocean can either be closed, periodically or permanently open, allowing a variety of exchanges between marine and freshwater. These unique ecosystems are critically important for marine and freshwater habitats, including fish, invertebrates, bird and plant species. The southern African coastline stretching between Mozambique to Angola, has very few sheltered environments available for sensitive coastal and freshwater habitats to exist. A number of marine and fish species occupy estuaries for the nursing of their offspring.
Our estuaries therefore offer valuable protection, not only for marine species, but also for a high diversity of animal and plant species. The ecological importance of South Africa’s estuaries is thus captured in the ability of these systems to support resident and migratory species, supporting a range of ecological processes. As a result, these ecosystems are usually highly productive.
River mouth outlet to ocean, Great Brak Estuary, Southern Cape, South Africa
South Africa’s estuaries are however threatened by social and economic activities traditionally associated with these ecosystems. According to the South African National Biodiversity Institute, the estimated monetary value of commercial fishing from estuaries, equals R923 million (about US$ 115 million) annually. On the social front, estuaries with their highly attractive views and pleasant environment, is sought after areas for residential and even commercial and tourism development. Recreational activities follow, including birding, fishing and bait collection, swimming, and boating. On a more subsistence level, estuaries are the livelihood for many communities depending on estuary harvesting including prawns, bait and worms as the sole source of income. The Eastern Cape’s prominent Swartkops estuary is one of the country’s most prominent estuaries in economic terms. This estuary has an estimated ecological value of R38.2 million (about US$4.75 million) and annually generates R50 million (about US$6.25 million) from tourism.
With the above in mind, the Minister of Environmental Affairs publicly confirmed during the National Marine Week: our estuaries the need better, increased and more stringent protection. Anthropogenic or human induced pollution, including untreated wastewater and industrial effluent, are two major pollution sources threatening the well-being and functioning of the country’s estuaries.
South Africa’s estuaries are thus in great need of the development and implementation of holistic management plans, such as developed by the CAPE Estuaries Programme. Following rigorous management research and extensive stakeholder involvement, the final management plans for the country’s major estuaries were developed and are in the early stages of implementation. Ultimately, the goal is to expand estuary management to all 295 estuaries across the country’s coastline, offering better protection for these valuable ecosystems and ensuring long-term sustainability.
Sources: http://www.allAfrica.com; South African Biodiversity Institute and the Nelson Mandela Metropolitan University
Photographs: some rights reserved by jimmedia via flickr (Cover Photo); and all rights reserved by Word from the Savanna (Article Photos).