| || || Appana, Subhashni Devi.|
| || || Abundance, spatial distribution and bioerosion of the sea urchins, Echinometra spp. on Nukubuco Reef, Suva, Fiji |
Author:Appana, Subhashni Devi.
Institution: University of the South Pacific.
Subject: Sea urchins -- Fiji -- Nukubuco Reef
Call No.: Pac QL 384 .E2 A662 2001
Copyright:Under 10% of this thesis may be copied without the authors written permission
Abstract: Nukubuco Reef, in Fiji is of interest because of the low-medium but consistent numbers of novel species of Echinometra. Additionally the natural and anthropogenic disturbances it experiences continuously make it more important to be studied. The coral reef system in Laucala Bay in which Nukubuco Reef is a part, has been stressed by recent bleaching events (South and Skelton 2000; Cumming et al. under review) and by overfishing efforts of the adjacent communities. The influx of partly treated sewage from Kinoya Sewage Treatment Plant (Naidu et al 1991 promotes nutrient enrichment to the Laucala waters with coincident Acanthaster planci outbreaks (Zann et al. 1990). High sediment loads from logging and intensive farming (Hinrichsen 1998) and sand dredging activities (Perm 1983) amplify coral reef decline. This study aims to provide valuable information and understanding of the ecology of these abundant sea urchins, Echinometra sp. A and E. sp. C which will be referred to in this thesis as E. sp. A and E. sp. C hereafter. The study will investigate the role of urchins in changing the coral community structure through grazing and bioerosion. The results from this study will also serve as a baseline for future assessments of the health of Nukubuco Reef. To achieve the aims of this study, Chapter 1 will present a comprehensive literature review of population and bioerosion studies of Echinometra. Chapter 2 will provide general background information on Nukubuco Reef and report on the preliminary study undertaken. Chapter 3 will adopt a multi-scale approach to report the distribution and abundance patterns of E, sp. A and E. sp. C. The position (east and west) factor will be studied to identify the effects of (Matsuoka and Hatanaka 1991). Hibino and Van Woesik (2000) did a spatial and seasonal carbonate budget study on the Ryukyu Islands, Japan on the E. mathaei types A, B, C, D. The small genetic and morphologic differences among species coupled with their strong reproductive isolation made them a valuable group for studies of marine speciation (Palumbi 1996a).