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Coral reefs in Moorea, French Polynesia, suffered catastrophic coral mortality through predation by Acanthaster planci from 2006 to 2010, and Cyclone Oli in 2010, yet by 2015 some coral populations were approaching pre-disturbance sizes. Using long-term study plots, we quantified population dynamics of spawning Pocillopora spp. along the north shore of Moorea between 2010 and 2014, and considered evidence that population recovery could be supported by self-seeding. Results scaled up from study plots and settlement tiles suggest that the number of Pocillopora spp. colonies on the outer reef increased 1,890-fold between 2010 and 2014/2015, and in the back reef, 8-fold between 2010 and 2014/2015. Assuming that spawning Pocillopora spp. in Moorea release similar numbers of eggs as con-generics in Hawaii, and fertilization success is similar to other spawning corals, the capacity of Pocillopora spp. to produce larvae was estimated. These estimates suggest that Pocillopora spp. in Moorea produced a large excess of larvae in 2010 and 2014 relative to the number required to produce the recruits found in the back reef and outer reef in 2010 and 2014, even assuming that ∼99.9% of the larvae do not recruit in Moorea. Less than a third of the recruits in one year would have to survive to produce the juvenile Pocillopora spp. found in the back and outer reefs in 2010 and 2014/2015. Our first order approximations reveal the potential for Pocillopora spp. on the north shore of Moorea to produce enough larvae to support local recruitment and population recovery following a catastrophic disturbance.
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The scaling of metabolic traits differs among larvae and juvenile colonies of scleractinian corals
ABSTRACT Body size profoundly affects organism fitness and ecosystem dynamics through the scaling of physiological traits. This study tested for variation in metabolic scaling and its potential drivers among corals differing in life history strategies and taxonomic identity. Data were compiled from published sources and augmented with empirical measurements of corals in Moorea, French Polynesia. The data compilation revealed metabolic isometry in broadcasted larvae, but size-independent metabolism in brooded larvae; empirical measurements of Pocillopora acuta larvae also supported size-independent metabolism in brooded coral larvae. In contrast, for juvenile colonies (i.e. 1–4 cm diameter), metabolic scaling was isometric for Pocillopora spp., and negatively allometric for Porites spp. The scaling of biomass with surface area was isometric for Pocillopora spp., but positively allometric for Porites spp., suggesting the surface area to biomass ratio mediates metabolic scaling in these corals. The scaling of tissue biomass and metabolism were not affected by light treatment (i.e. either natural photoperiods or constant darkness) in either juvenile taxa. However, biomass was reduced by 9–15% in the juvenile corals from the light treatments and this coincided with higher metabolic scaling exponents, thus supporting the causal role of biomass in driving variation in scaling. This study shows that metabolic scaling is plastic in early life stages of corals, with intrinsic differences between life history strategy (i.e. brooded and broadcasted larvae) and taxa (i.e. Pocillopora spp. and Porites spp.), and acquired differences attributed to changes in area-normalized biomass.
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- Award ID(s):
- 2224354
- PAR ID:
- 10510708
- Publisher / Repository:
- https://mcr.lternet.edu/bibliography
- Date Published:
- Journal Name:
- Journal of Experimental Biology
- Volume:
- 227
- Issue:
- 9
- ISSN:
- 0022-0949
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1242/jeb.246362
