Recruitment and growth of scleractinian corals in relation to Bio-physical processes in reefs of Unguja island, Zanzibar, Tanzania
Loading...
Date
2014
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Dar es Salaam
Abstract
This study was conducted to examine the dynamics of key ecological processes that effect the recovery of reef communities, which include the recruitment and growth of juvenile corals, and their relationships with reef herbivory, corallivory, and sedimentation stress. The study was undertaken on Chumbe, Changuu and Mnemba reefs in Zanzibar, from October 2010 to June 2012. The juvenile corals and invertebrate herbivores assessments were done in Situ in permanent quadrats whereas herbivorous and corallivorous fish were assessed using under water visual sensor method. The results revealed significant differences in juvenile coral densities and survival rates among reef sites. There was significant site habitat variability in juvenile coral density at Changuu and Mnemba. Corals of the Genus Acropora at Chumbe, Porites at Changuu and Mnemba. Growth rates (cm2 6-month-1) of juvenile corals species ranged from 8.1 (for Porites lutea) to 155.7 (for echinopora lamellosa). High growth and survival rates were observed on reeef slope relative to the reef crest and reef flat. Sea urchin density and diversity was highest at Changuu whereas the lowest sea urchin diversity and density were recorded at Mnemba and Chumbe, respectively. Herbvorous fish densities at Mnemba. At Chumbe, juvenile, corals were positively influenced by herbivorous within sites. Sedimentation rates (mg cm-2 day -1) were highest at Chumbe reef (4.67) and lowest at Mnemba reef (!.22), with marked seasonal and habitat variations within sites examined. The results indicated considerable natural recovery potential differences among reef sites. However, appropriate management measures to the degraded reefs can facilitate reef recovery process.
Description
Available in printed form, East Africana Collection, Dr. Wilbert Chagula Library, Class mark (THS EAF QL377.C5Z36U76)
Keywords
Seleractinia, Coral reefs, Unguja Island, Zanzibar, Tanzania
Citation
Ussi, A.M (2014) Recruitment and growth of scleractinian corals in relation to Bio-physical processes in reefs of Unguja island, Zanzibar, Tanzania.Doctoral dissertation, University of Dar es Salaam, Dar es Salaam.