The purpose of this study is to investigate the distribution and growth of the Black-Disease-causing Terpios hoshinota, including the effects of light, depth and nutrient on their growth at Green Island and Orchid Island. We also simulated the future coverage of black disease based on present data. Most T. hoshinota colonies were distributed at 2-3 meters (0-62 ind./100 m2) and the densities decrease with depth (0-5 ind./100 m2, at 10 m). The BD density at north and east coast were higher than that at west coast at Green Island, but no such difference occurred at Orchid Island. There were many small sponges and the number decrease with size. The frequency distribution of log-transformed lengths displayed a normal distribution. In comparing various recruitment models, i.e., normal, uniform, exponential and seasonal, we found that the actual size distribution is only compatible with the exponential temporal pattern. Thus more and more recruits may be entering the population continuously. The average growth rate of T. hoshinota is 0.18 cm/day, therefore the largest sponge at Green Island might have grown for only 2-4 years (340 cm).Two independent nutrient experiments did not detect the effects of nutrient addition on growth rates of the sponge. Comparison of BD densities and house numbers near the reef failed to reveal correlation. Most sponge colonies could not grow normally when shaded. The sponges transported to deeper water (15-20 m) might suffer tissue loss, but if they survived, they grew as fast as those controls at shallow waters (5-10 m). Growth rates of T. hoshinota differed by seasons within our testing period from April to July, 2008. The sponge expanded slower on non-coral substrate, at about 55% the rate, than those on corals. T. hoshinota grow on artificial substrate like glass, antifouling coatings, soft corals and other sponges. Using BD densities, sizes, growth rates and coral coverage, we simulated the BD colony distribution to predict its future coverage. We found that the sponge has the potential to cover the shallow reefs in 3-5 years at Green Island. The actual rate of increase at Gon-guan reef between 2007 and 2008 supports the above prediction.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0205109-165803 |
| Date | 05 February 2009 |
| Creators | Lin, Wen-ju |
| Contributors | Keryea Soong, Chang-feng Dai, Hsing-Juh Lin, Hsing-Juh Lin, Chao-lun Chen |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0205109-165803 |
| Rights | unrestricted, Copyright information available at source archive |
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