Restoration of coral populations in light of genetic diversity estimates

Abstract

Due to the importance of preserving the genetic integrity of populations, strategies to restore damaged coral reefs should attempt to retain the allelic diversity of the disturbed population; however, genetic diversity estimates are not available for most coral populations. To provide a generalized estimate of genetic diversity (in terms of allelic richness) of scleractinian coral populations, the literature was surveyed for studies describing the genetic structure of coral populations using microsatellites. The mean number of alleles per locus across 72 surveyed scleractinian coral populations was 8.27 (±0.75 SE). In addition, population genetic datasets from four species (Acropora palmata, Montastraea cavernosa, Montastraea faveolata and Pocillopora damicornis) were analyzed to assess the minimum number of donor colonies required to retain specific proportions of the genetic diversity of the population. Rarefaction analysis of the population genetic datasets indicated that using 10 donor colonies randomly sampled from the original population would retain >50% of the allelic diversity, while 35 colonies would retain >90% of the original diversity. In general, scleractinian coral populations are genetically diverse and restoration methods utilizing few clonal genotypes to re-populate a reef will diminish the genetic integrity of the population. Coral restoration strategies using 10–35 randomly selected local donor colonies will retain at least 50–90% of the genetic diversity of the original population.

Rarity and genetic diversity inIndo–PacificAcroporacorals

“…Mean allelic richness for all species/loci examined in this study showing that most Acropora species have lower mean allelic richness than what is considered a "conservative mean" in a review of scleractinian coral genetic diversity(Shearer et al 2009 pertaining to non-Acropora corals only).1878ª 2012 The Authors. Ecology and Evolution published by Blackwell Publishing Ltd.…”

Colony growth of corals transplanted for restoration depends on their site of origin and environmental factors

“…The success of these restoration efforts depends partly on whether characteristics of source populations influence the performance of corals after they are transplanted (Shearer et al . ). Local adaptation might result in poor performance of individuals transplanted to a restoration site from elsewhere (Baums ).…”

“…Corals are in decline worldwide (Gardner et al 2003;Bellwood et al 2004), and transplanting colonies from surviving populations to sites where species have become rare or eliminated is gaining popularity as a restoration method (Yap 2000;Rinkevich 2005;Precht 2006). The success of these restoration efforts depends partly on whether characteristics of source populations influence the performance of corals after they are transplanted (Shearer et al 2009). Local adaptation might result in poor performance of individuals transplanted to a restoration site from elsewhere (Baums 2008).…”

No two reefs are created equal: fine-scale population structure in the threatened coral species Acropora palmata and A. cervicornis

“…When genetic methods are coupled with ecological and oceanographic studies (Baums et al 2006a, Galindo et al 2006, Hellberg 2007, Grober-Dunsmore et al 2007, Zubillaga et al 2008), a more comprehensive management plan can be implemented. Management decisions can be further fine-tuned by the inclusion of genetic information in restoration projects (Baums 2008, Shearer et al 2009) and by the identification of disease-resistant genotypes (Vollmer & Kline 2008). …”