Inter-Research
Marine Ecology Progress Series

ABSTRACT: Tissue injury, in which the skeleton is stripped of living tissue, is common in reef-building corals and has potentially important demographic consequences. To examine the significance of tissue injury for natural populations, I monitored 1627 colonies in 30 taxa of Indo-Pacific branching corals at 3 to 5 mo intervals over a 2 yr period. Recent injury (inflicted within the few days prior to censusing) was a highly significant predictor of colony fate within 3 to 5 mo, for acroporid corals with small, compact branches (hispidose and corymbose growth forms). In contrast, colony size was not a significant predictor of fate for these corals after recent injury was included in the models. Both recent injury and colony size were significant predictors of fate for pocilloporids (small bushy growth form). Neither were good predictors of fate for arborescent acroporids (large, widely-spaced branches), even though recent injury was up to 3 times more common in these corals. Old injury (inflicted several weeks or more prior to censusing) covering >5% of the colony was a highly significant predictor of colony death within 3 to 5 mo for corymbose species. Colonies with both old and recent injuries were highly likely to die: 33 and 54% of colonies in separate censuses died within 3 mo. The predictive power of recent injury implies chronic or repetitive tissue loss and prolonged decline, since most recent injuries were small (<30 cm²) and did not account for the colony decline per se. Since colony size was not as good a predictor of colony fate as recent injury for small-branched acroporids, size-based population models for these corals may be improved by incorporating tissue injury as an indicator of colony condition.

KEY WORDS: Demographic fate · Size-based population model · Growth form · Indicator · Log- linear modeling · Partial mortality · Acropora · Pocilloporid · Predictor · Reef-building coral · Injury

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Published in MEPS Vol. 242 (2002) on October 25
Print ISSN: 0171-8630; Online ISSN: 1616-1599. Copyright © Inter-Research, Oldendorf/Luhe, 2002