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Demographic aspects of the soft coral Sinularia flexibilis leading to local dominance on coral reefs

  • C. Bastidas
  • K. E. Fabricius
  • B. L. Willis
Conference paper
Part of the Developments in Hydrobiology book series (DIHY, volume 178)

We evaluated the role that demography may play in the formation of local aggregations of Sinularia flexibilis (Quoy & Gaimard, 1833), a soft coral that commonly dominates inshore coral reefs of the Great Barrier Reef (GBR), Australia. Two populations on inshore reefs of the Palm Islands were censused once a year for 3 years, starting 10 mo after the extensive bleaching mortality in early 1998. Larger colonies became more prevalent over time; mean colony size increasing by 35%, from 276 cm2 in 1998 to 373 cm2 in 2000. Growth rates were size dependent, with smaller colonies growing proportionally faster than larger colonies. Change in size relative to initial size indicated an expected mean annual growth of 128 cm2 for a 50-cm2 colony. Zero growth was predicted at 532 ± 21 cm2, with colonies larger than this likely to undergo fission or shrink. Forty-three percent of colonies were undergoing fission at any time at both localities. Most new colonies were produced by fission (70%, n = 285), with the remainder produced by the recruitment of sexually produced larvae (19%) or by colony translocation (11%). The sexual and asexual recruitment rates were 0.24 and 1.0 recruits m–2 year–1, respectively. Opportunistic recruitment and rapid growth following disturbances are commonly assumed to be the mechanisms leading soft corals to dominate locally. In this study, these mechanisms operated more slowly than expected, with no net change in population size.

Key words: GBR, population dynamics, Sinularia, soft corals

Keywords

Coral Reef Colony Size Great Barrier Reef Soft Coral Large Coloni 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • C. Bastidas
    • 1
  • K. E. Fabricius
    • 1
  • B. L. Willis
    • 2
  1. 1.Australian Institute of Marine ScienceAustralia
  2. 2.School of Marine Biology and AquacultureJames Cook UniversityAustralia

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