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 Academic Background
Sean graduated from the University of Natal , Durban with a BSc Chemical Engineering degree in 1987. Following compulsory National Service, he worked as a chemical engineer for over 13 years, gaining experience in plant operations, technical development and process plant design in the hydrometallurgical processes. Dissatisfied with his chosen career path, he returned to university, taking botany and zoology courses while completing his MSc in Chemical Engineering at UCT. The MSc Thesis is titled: “ Environmental considerations in the Design of Base Metals Refineries - A focus on metals in riverine systems ”.
Sean has always been interested in environmental matters and registering for a PhD in Zoology under Jenny Day in 2004. He completed selected modules of the Conservation Biology MSc course to provide the necessary conservation foundation for his PhD work. Sean has an interest in restoration ecology and the management of invasive alien species, especially trees and freshwater fish species.
The future of our indigenous freshwater fishes is in our hands (Sawfin ( Barbus serra ) from the Driehoeks River in the Cederberg) (Photo: Darragh Woodford)
Current research
My PhD has two major themes and a number of supporting minor themes. The major themes are the conservation of indigenous fish species of the Cape F loristic Region and Mitigation of the impact of introduced (alien) piscivorous fish. Alien invasive fish pose the single greatest threat to the survival of the indigenous freshwater fishes of the Cape F lori stic Region and thus the two themes are interrelated.
The secondary themes of my research include evaluating freshwater aquatic conservation, establishing suitable methods to determine freshwater fish population size and distribution, evaluating social perceptions to indigenous and introduced freshwater fishes in the Cape F lori stic Region and evaluating methods to eradicate the introduced fish from the rivers of the Cape F lori stic Region.
The conservation theory for aquatic ecosystems will be investigated and the applicability of terrestrial based theory for aquatic ecosystems evaluated. If necessary, aquatic conservation theory will be developed for rivers in the Cape F lori stic Region. The aim is to develop a scientifically based conservation protocol for the indigenous fishes of the Cape F lori stic Region. This will be published in an Action Plan for the Freshwater Fishes of the Cape F lori stic Region
Estimating the population of freshwater fishes is notoriously difficult. Selected population estimation techniques will be evaluated to determine the most appropriate method and statistical interpretation for the species present in the streams of the Cape F lori stic Region. It is expected that species such as Galaxias zebratus will prove to be challenging to evaluate.
Fishermen support the presence of these fish and landowners, seeking to generate additional income from their land resources, prefer alien fish to indigenous because of their economic (fishing) value. In order to promote the conservation of the indigenous freshwater species, it is important to understand the perceptions of the fishermen and landowners towards indigenous and introduced species. A questionnaire based social survey will be conducted to evaluate the perceptions of these two groups and to determine the drivers which result in the stated preferences. The social survey will provide valuable information regarding possible approaches to influence the perceptions and attitudes of the fishermen and landowners.
In order to conserve the indigenous fish communities and to prevent mass extinction of our indigenous assemblages, urgent action is required to mitigate the effect of the introduced fish. Eradication of introduced fish is not a simple task. A GEF funded project to use the piscicide Rotenone to eradicate fish from selected reaches of rivers in the Cederberg and Little Karoo will form the bulk of the evaluation of eradication techniques. The fish populations and distribution prior to, and post, rotenone application will be evaluated. The rate of re-colonisation by indigenous species from upstream refuges will be monitored. The effect of the rotenone application on other assemblages, e.g. invertebrates, will also be monitored. Alternative eradication techniques, such as the use of spawning fish's pheromone to attract the remainder of the school into a trap, will be evaluated on a smaller scale.
Contact details:
Freshwater Research Unit
Department of Zoology
University of Cape Town
Private Bag X3
Rondebosch, 7701
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