Reef-building coral taxa demonstrate considerable flexibility and diversity in reproduction and growth mechanisms. Corals take advantage of this flexibility to increase or decrease size through clonal expansion and loss of live tissue area (i.e. via reproduction and mortality of constituent polyps). The biological lability of reef-building corals may be expected to map onto varying patterns of demography across environmental contexts which can contribute to geographic variation in population dynamics. Here we explore the patterns of growth of two common coral taxa, corymbose Pocillopora and massive Porites, across seven islands in the central and south Pacific. The islands span a natural gradient of environmental conditions, including a range of pelagic primary production, a metric linked to the relative availability of inorganic nutrients and heterotrophic resources for mixotrophic corals, and sea surface temperature and thermal histories. Over a multi-year sampling interval, most coral colonies experienced positive growth (greater planar area of live tissue in second relative to first time point), though the distributions of growth varied across islands. Island-level median growth did not relate simply to estimated pelagic primary productivity or temperature. However, at locations that experienced an extreme warm-water event during the sampling interval, most Porites colonies experienced net losses of live tissue and nearly all Pocillopora colonies experienced complete mortality. While descriptive statistics of demographics offer valuable insights into trends and variability in colony change through time, simplified models predicting growth patterns based on summarized oceanographic metrics appear inadequate for robust demographic prediction. We propose that the complexity of life history strategies among colonial reef-building corals introduces unique demographic flexibility for colonies to respond to a wide breadth of environmental conditions.
|Original language||English (US)|
|Title of host publication||Advances in Marine Biology|
|Editors||Bernhard M. Riegl|
|Number of pages||25|
|State||Published - Jan 2020|
|Name||Advances in Marine Biology|
Bibliographical noteFunding Information:
This research was made possible through efforts of the 100 Island Challenge, and the various organizations that have supported this project, including the Scripps family and the Moore Family Foundation. We would like to acknowledge the efforts of Lindsay Bonito, Angelica Dimas, and Mary Liesegang for their assistance in the field and in the laboratory. Special thanks to the people of the Republic of Kiribati, colleagues from the New England Aquarium, Prince Albert of Monaco II, and Sangeeta Mangubhai for coordinating and supporting access to the Phoenix Islands. The authors declare no conflicts of interest.
© 2020 Elsevier Ltd
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Aquatic Science