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Title:
Developing efficiency of capture and culture methods of coral reef fish larvae
Untitled
Author:
Waqalevu, Viliame P.
Institution:
University of the South Pacific.
Award:
M.Sc.
Subject:
Date:
2012.
Call No.:
Pac QL 639 .25 .W37 2012
BRN:
1186441
Copyright:
Over 80% of this thesis may be copied without the authors written permission
Abstract:
The vertical distribution and the horizontal distribution of fish post-larvae in the water column immediately prior to colonization were tested on the outer reef slope of Moorea Island, French Polynesia from February to June, 2010. 21 fish families, consisting of 47 species and 575 post-larvae from 54 samples were caught during sampling at various depths (2 m, 15 m, and 25 m) at an approximate distance of 100 m from the reef crest. Abundance and species richness was found to be significantly higher in sub-surface samples than in deeper samples. Abundance, species richness and the economic value of the post-larval catch was found to decrease with the depth of sampling. 21 families consisting of 40 reef fish species and 720 post-larvae from 58 samples were collected at sub-surface and bottom sampling at different reef zones of the outer reef slope. Abundance, species richness and economic value of the post-larval catch were found to be highest when sampling at the surface closer to the reef crest than further away from the reef crest. A total of 29 fish species that were viable for the aquarium trade were caught throughout the duration of this study. The post-larval market price of the species caught ranged from $0.70 to $14.10 (USD). The colonization of fish post-larvae showed a strong seasonal pattern which coincided with different lunar phases and the low catch rate could have been influenced due to the fact that 2010 was an El Nino year. A custard feed made from locally available materials were tested on Dascyllus aruanus newly settled and juveniles to assess growth rates (SGR, RGR, DWG) and survival against the more popular Artemia diet. Shrimp custard was observed to have the highest growth followed by Squid and Artemia. Significant differences were observed across the tested feeds proving that locally made feed is a cheaper alternative and is as good as, and also better in promoting growth as the imported Artemia. Temperature maintenance was observed as a vital parameter in the culture of D. aruanus as mass mortality was observed in unheated replicates. Custard feed was found to be suitable for D. aruanus as they were observed to feed avidly at first feeding. A closed system of water circulation was adopted for this experiment.
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