The recruitment, growth rate and survival of every juvenile corals on artificial substrates, deployed every 2 months since September 1998, for a total of 6 times, were investigated every 2 months, from November 1998 to September 2000, at Nanwan, southern Taiwan. The influence of season and habitat (e.g., new vs. old substrate and different positions etc.) on the above life history characteristics were the foci of this study.
Coral recruitment during the 2-year period was low, averaging 1.3 recruits per 15x15 cm PVC plate; it was dominated by Pocilloporidae (50.7%) and Poritidae (31.9%), with Stylocoeniella guentheri (6.2%), Anthelia flava (5.1%) and Acropora sp. (2.4%) and others as minor constituents.
Seasonal variations of new recruit densities were significant on new substrates of 2-months old, but not on old substrates of 14-month old. Pocilloporidae, for example, had the highest new recruit densities in May 1999; although the survival rate in this period, cumulative survivorship and growth rate were lower than those settled in other times.
New recruit densities on new substrates were significantly higher than that on old substrates, but the survival rates of new recruits in the first 2 months were not significantly different between new and old substrates. The cumulative suvivorship and the initial juvenile growth rate of Pocilloporidae were higher on new than on old substrates.
New recruit density of Pocilloporidae was higher in 1999 than in 2000, with an opposite pattern found in Poritidae. Juveniles prefer to settle on new substrates higher than old substrates and recruit densities decrease as plate age in Pocilloporidae, but an opposite pattern was found in Poritidae. The Pocilloporidae had relatively higher recruit densities but lower cumulative survivorship than Acropora sp. and Stylocoeniella. guentheri.
A margin effect on the PVC plates was found, with higher new recruit densities and growth rates in the margin than in the intermediate and the inner region. The survival rate and the cumulative survivorship of recruits, however, were similar among the 3 regions on the plates. Thus the pattern of margin effect on the plate is unlikely a result of active larva preference.
Among the scleractinian recruits, Acropora sp. had the highest growth rate, averaging 1.8 mm/month in maximum diameter. Within Pocilloporidae, the maximum diameters of juvenile Seriatopora hystrix was significant smaller than Pocillopora damicornis from 2-12 month. Some recruits of Seriatopora hystrix did not grow for more than a year.
The overall cumulative survivorship of coral recruits was low at Nanwan, with 29.2% surviving the first year, and 0.7% surviving 2 years. Within dead juveniles, 65.7% was caused by disappearance and 34.3% was caused by algae, sediment and others organism etc. The relationship between size and mortality on juvenile Pocilloporidae is significant, implying that larger colony corals have higher survivor chance than smaller colony corals.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0620101-153006 |
| Date | 20 June 2001 |
| Creators | Kuo, Kun-Ming |
| Contributors | Chao-Lun Chen, Tung-Yung Fan, Chin-Seng Chen, Chang-Feng Dai, Keryea Soong |
| 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-0620101-153006 |
| Rights | unrestricted, Copyright information available at source archive |
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