Abstract
Indicators of condition on the marginal, high-latitude coral reefs of KwaZulu-Natal, South Africa
Western Indian Ocean Marine Science Association (WIOMSA) Scientific Symposium : Science Policy and Management: Pressures and Responses in the Western Indian Ocean Region, 5th (Durban, South Africa, 22-Oct-2007–26-Oct-2007)
2007
Abstract
The condition of coral reefs and other marine ecosystems is deteriorating globally. South Africa's coral communities are no exception. But unlike other Indian Ocean reefs, they have been relatively unaffected by pollution, overexploitation, diver damage, destructive fishing practices and climate-mediated coral bleaching. Nevertheless, with greenhouse gas emissions and human population pressure increasing, these reefs are likely to be subjected to more frequent and more intense disturbances in the future. Consequently, it has become essential to implement management initiatives that ensure sustainable utilisation of the marine resources associated with these coral reefs and that alleviate potential user conflicts. Recently there has been a shift away from conventional monitoring approaches that require excessive expenditure and sophisticated equipment. Instead, bio-indicators have been proposed as effective alternatives to assess ecosystem condition because they are cost effective and require uncomplicated analysis. Our study takes this approach a step further by seeking a suite of biotic indicators that reflect not only community structure, but also ecological processes such as predation, competition and reproduction. We hypothesize that contrasting patterns of use on reefs will affect their natural functioning through these processes. Therefore, indicators that can detect changes in such processes would be valuable additions to monitoring schemes that aim to identify and alleviate overexploitation or to protect sensitive areas. We used a combination of stationary visual point counts and photo- quadrats to validate the effectiveness of bio-indicators in assessing reef condition. We found that coral-associated indicators have strong host specificity and that there are large differences in the density of these species among reefs of contrasting use. We also found that abundances and average lengths of predatory fish to be highest on least-disturbed reefs. Ongoing experiments are investigating the links between biological condition of the coral communities and possible causative agents.
Details
- Title
- Indicators of condition on the marginal, high-latitude coral reefs of KwaZulu-Natal, South Africa
- Authors
- C Floros (Author) - Oceanographic Research Institute, South AfricaM Schleyer (Author) - Oceanographic Research Institute, South AfricaDavid S Schoeman (Author) - University of KwaZulu-Natal, South Africa
- Conference details
- Western Indian Ocean Marine Science Association (WIOMSA) Scientific Symposium : Science Policy and Management: Pressures and Responses in the Western Indian Ocean Region, 5th (Durban, South Africa, 22-Oct-2007–26-Oct-2007)
- Date published
- 2007
- Organisation Unit
- School of Science and Engineering - Legacy; University of the Sunshine Coast, Queensland; School of Science, Technology and Engineering
- Language
- English
- Record Identifier
- 99450028002621
- Output Type
- Abstract
Metrics
4 File views/ downloads
343 Record Views