Economic relevance of Zandvlei Estuary.
CAPE Estuaries Programme: Implementation of the Estuary Management Plan (EMP) for the Zandvlei Estuary, Muizenberg, Cape Town.
On page 33 of their August 2007 report “Development of a Conservation Plan for Temperate South Africa Estuaries on the basis of Biodiversity Importance, Ecosystem Health and Economic Cost and Benefits’ the lead authors, Jane Turpie and Barry Clark (Turpie/Clark) identify five key components in estuarine ecosystem goods and services.
These five components are linked through “Use Value” and “Non-use Value” to give a Total Economic Value. See Figure 1 below. - not alvailable.
Applying these five components to the Zandvlei the following emerges.
1. CONSUMPTIVE USE VALUE
The Zandvlei Estuary is used by both recreational and subsistence fishermen. The subsistence fishermen, particularly, make use of the fish caught either for direct food for their families or to raise cash by selling them. The sand banks of the vlei are also harvested for prawns.
2. NON CONSUMPTIVE USE VALUE
Non Consumptive Use Value is the use of the estuary which does not take away anything of value from the site. The Zandvlei Estuary is a major recreational and sport activity area. These activities includecanoeing, sailing, fishing, and wind-surfing on the water and picnicking, braaing and informal games on the banks.
3. INDIRECT USE VALUE (ECOSYSTEM FUNCTIONS)
3.1. G. Prince of the Cape Piscatorial Society comments on the importance of Zandvlei as a nursery for juvenile marine fish species. He writes;
3.2. Bird life. The Zandvlei Estuary is an important feeding and breeding ground for a large number of birds.
3.3 Western Leopard Toad. The wetlands to the west of the Zandvlei are a major breeding site for the endemic and endangered Western Leopard Toad.
4. OPTION OR FUTURE VALUE
Turpie and Clarke write: Option value is the future value of resources and services offered by ecosystems such as possible medicinal, leisure, agricultural or industrial uses. Option value is particularly important when there is still uncertainty regarding the potential use and value of the ecosystem later on (Nhuan et al. 2003; Perman et al. 1996, Barbier 1993). Even though an estuary may be underutilised at present, it may possibly be valuable for scientific research, education, tourism and other commercial enterprises which would increase its economic value in the future (Barbier 1993)”.
In this context the Zandvlei has been used as a training centre for foreign rowing teams. This generates income in surrounding hotels and guest houses. The opportunity exists for this utilisation to be upgraded.
Turpie / Clark continue “A quasi-option value is the value obtained from not undertaking irreversible activities in order to retain options for future use of the ecosystem (Perman et al. 1996). “Ecosystem functions may either generate outputs that form inputs into production processes elsewhere (in other words the benefits are realised off-site)”. This function is best exemplified by the role the Zandvlei plays as a nursery for marine fish.
Turpie/Clark continue “or they result in engineering costsavings by performing functions that would otherwise require costly infrastructure or manmadeprocesses. The provision of ecosystem services is generally positively related to thelevel of health or integrity of
5. EXISTENCE VALUE.
Work by Bin and Polesky in the United States (quoted by Turpie/Clark p36) found that proximity to coastal wetlands has a positive association withthe nearby property value. Reducing the distance to the nearest coastal wetland by 1000 feet raised the property priceby $US1010 at the initial distance of one mile. The Zandvlei has domestic residences on both the east and west sides. The Marina da Gama is a clear indication of the value of the existence of the Zandvlei Estuary and the property values associated with it. Should the health of the Zandvlei system diminish, leading to pollution and unpleasant smells the property values of the surrounding residences could be reduced changing from a desirable to an undesirable location to have a home.
Turpie / Clark (p 50) write: Respondents claimed that scenic beauty and biodiversity were the main factors contributingto the existence value of a particular estuary. The economicand subsistence contribution was considered slightly more important, suggesting that theyvalued estuaries for the contribution to society as well as to biodiversity”.
A study on the value and condition of Temperate South African Estuaries used five indicators for the assessment of the economic relevance of an estuary. In all five categories of the evaluation the Zandvlei is represented and can be shown to make a positive economic contribution.