Data from: Symbiont community and host genetic structure of the brain coral Platygyra verweyi, at the outlet of a nuclear power plant and adjacent areas

In the context of rising seawater temperatures associated with climate
change, the issue of whether coral holobionts deal with this challenge by
shuffling their associations with stress- and/or heat-tolerant
Symbiodinium, by generating heat-resistant host genotypes, or both is
important for coral survival. In the present study, the composition of
communities of the endosymbiont Symbiodinium and the population genetics
of the coral host Platygyra verweyi were examined in a reef impacted by
hot water discharged from the outlet of a nuclear power plant in operation
in Kenting, Southern Taiwan since 1984. The water at this site is 2.0-3.0
ºC warmer than adjacent reefs in summer, which have an average seawater
temperature of 29.0 ºC. The data were compared with those for the same
species at other sites within 12 km of the outlet site. Platygyra verwyei
was associated with one or both of Symbiodinium types C3 (heat sensitive)
and D1a (heat tolerant) at all sites with the latter being the dominant at
the nuclear power plant outlet. The proportion of C3 in populations
increased gradually with increasing distance from the hot-water discharge.
Genetic analysis of the Platygyra verweyi host using mitochondrial and
nuclear markers showed no genetic differentiation among sites. Changes in
the composition of Symbiodinium types associated with P. verweyi among
closely located sites in Kenting suggested that this coral might have
acclimatized to the constant thermal stress by selective association with
heat-tolerant Symbiodinium types, whereas the role of the host in
adaptation was inconclusive.