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Resource economics of Donax serra in the Eastern Cape : evaluation of a small-scale clam fishery

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dc.contributor.advisor McLachlan A, Prof en
dc.contributor.author Sims R en
dc.date.accessioned 2016-09-22T13:18:54Z
dc.date.available 2016-09-22T13:18:54Z
dc.date.submitted 1997 en
dc.identifier.uri http://hdl.handle.net/20.500.11892/157336
dc.description.abstract In 1991, when a proposal was put forward to harvest Donax serra in the Eastern Cape for commercial gain, a classic economic dilemma arose; that of allocating scarce resources amongst competing uses. In this case, the competing uses were to commercially exploit the wedge clam populations for private gain or to leave them as they are, for the use and enjoyment of the general public. In order to shed light on the issue it was decided that a cost-benefit analysis (CBA) be carried out on the commercial exploitation. The CBA is based on a biologically sustainable extraction rate of 100 ton p.a., and a harvest strategy which minimised incidental mortality. From trial harvest experiments carried out, an attempt was made to quantify the degree of incidental mortality which could occur using the proposed extraction method. Incidental damage by forks was 10% and 16% by spades. Juveniles were the most susceptible to "mechanical" breakage. Of the clams landed, 33% were below the minimum legal size limit and 7% were not yet sexually mature. Public opinion on the proposed fishery was also surveyed. It is shown that the fishery activities might exact a price on society in the form of negatively altering the quality of people's recreation experience in the area, as well as its aesthetic and ecological attributes. The majority of visiting (89%) and resident (83%) beach users were opposed to the proposed fishery, fearing that such actions would eliminate the clam stocks (18 - 26%), tarnish the local beach ecology (24%), negatively alter recreation experience (4 - 9%) and ruin the visual and aesthetic beauty of the area (25 - 35%). Visitors were willing to pay R21.60 per person per visit to prevent the fishery from going ahead and therefore preserve the attributes of the beach that they enjoyed and residents R10.42. From this information two external costs were estimated: one for (i) loss of recreation quality through beach users coming in direct contact with harvesting activities and another for (ii) loss of personal satisfaction experienced by all beach users opposed to the fishery. Results from the CBA yielded positive net present values (NPVs) for project options involving the live clams being sold on the export market (Hong Kong) for R24.70/kg and negative NPVs for domestic market options (Johannesburg and Cape Town) where the clam would be sold for R6.50/kg. Assuming a discount rate of 8%, the highest NPV was obtained for the scenario in which total production was sold on the foreign market and the firm rented the facilities of an existing organisation. The external cost was the single largest component of the cost of the fishery. Social benefits should include the creation of about 8 employment opportunities for unskilled labour and 3 skilled labour positions, in addition to multiplier effects from new income in the Port Elizabeth region. The management strategy recommended includes the setting regulations to control fishing effort by using fishing permits, enforcing a minimum legal size limit and maximum annual quota, prohibiting mechanised harvesting methods and placing spatial and temporal restrictions on the fishery's activities. en
dc.language English en
dc.subject Invertebrates: Mollusca en
dc.subject Agriculture en
dc.subject Fisheries en
dc.title Resource economics of Donax serra in the Eastern Cape : evaluation of a small-scale clam fishery en
dc.type Masters degree en
dc.description.degree MSc en


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