J. Pineda, V. Starczak, A. Tarrant, J. Blythe, K. Davis, T. Farrar, M. Berumen, J. da Silva
Limnology & Oceanography, 58, pp. 1531-1545, (2013)
In summer 2010, a bleaching event decimated the abundant reef flat coral Stylophora pistillata
in some areas of the central Red Sea, where a series of coral reefs
100–300 m wide by several kilometers long extends from the coastline to
about 20 km offshore. Mortality of corals along the exposed and
protected sides of inner (inshore) and mid and outer (offshore) reefs
and in situ and satellite sea surface temperatures (SSTs) revealed that
the variability in the mortality event corresponded to two spatial
scales of temperature variability: 300 m across the reef flat and 20 km
across a series of reefs. However, the relationship between coral
mortality and habitat thermal severity was opposite at the two scales.
SSTs in summer 2010 were similar or increased modestly (0.5°C) in the
outer and mid reefs relative to 2009. In the inner reef, 2010
temperatures were 1.4°C above the 2009 seasonal maximum for several
weeks. We detected little or no coral mortality in mid and outer reefs.
In the inner reef, mortality depended on exposure. Within the inner
reef, mortality was modest on the protected (shoreward) side, the most
severe thermal environment, with highest overall mean and maximum
temperatures. In contrast, acute mortality was observed in the exposed
(seaward) side, where temperature fluctuations and upper water
temperature values were relatively less extreme. Refuges to thermally
induced coral bleaching may include sites where extreme, high-frequency
thermal variability may select for coral holobionts preadapted to, and
physiologically condition corals to withstand, regional increases in
water temperature.