%0 Journal Article
%T Coral Bleaching Susceptibility Is Decreased following Short-Term (1每3 Year) Prior Temperature Exposure and Evolutionary History
%A Joshua A. Haslun
%A Kevin B. Strychar
%A Gregory Buck
%A Paul W. Sammarco
%J Journal of Marine Biology
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/406812
%X Coral exposed to short periods of temperature stress (≡1.0∼C above mean monthly maximum) and/or increased frequencies of high temperatures may bolster resilience to global warming associated with climate change. We compared Montastraea cavernosa (Linnaeus, 1767; Cnidaria, Scleractinia, Faviidae) from the Florida Keys National Marine Sanctuary (FKNMS) and the Flower Garden Banks National Marine Sanctuary (FGBNMS). Thermal stress has been reported frequently within the FKNMS; however, corals in the FGBNMS experience nominal exposures to similar stressors. Corals were exposed to three temperatures (27∼C, 31∼C, and 35∼C) for 72ˋh. Colonies from the FKNMS lost significantly fewer viable and necrotic zooxanthellae under conditions of acute stress (35∼C) than the FGBNMS colonies. This indicates that the FKNMS corals are less temperature-sensitive than those in the FGBNMS. The observed differences point to greater prior temperature exposure and adaptation in the former versus the latter site when correlated to previous years of thermal exposure. 1. Introduction The earliest reefs are believed to have existed more than 3.4 billion years ago, dating back to the Early Archean era [1]. Reefs at that time were likely dominated by cyanophyceans and other bacteria [2]. More ※modern§ reefs consisting of coral and algae evolved during the Oligocene and Miocene, ~5 million years ago [3]. Present day reefs, such as the Indo-Pacific Great Barrier Reef (GBR) have evolved over the last 500每600ˋK years [4]. During each of these major eras of reef development, major climate changes throughout the geological time are believed to have influenced the evolution of species and the subsequently, adaptation of surviving species to these changes [1]. Such changes are believed to include the evolution of symbiosis. To better understand how future reefs will adapt to present-day climate changes, numerous studies have been done (reviewed in [5每10]). The causes of present-day crises on coral reefs is believed to be most likely a synergism between natural climate-related stress exacerbated by human-imposed stress. In 1998, heat stress is believed to have caused 48% of western Indian Ocean reefs and 16% of all reef areas globally to bleach [11, 12]. In 2002, extensive bleaching occurred on 60每95% of the world＊s barrier reefs, causing the loss of 50每90% of the corals there [12]. On the Great Barrier Reef, Australia, 50每60% of the reefs bleached, affecting 75,000 to 210,000ˋkm2 [13, 14]. Disease has also been a major cause of loss of coral cover in the Caribbean Sea. Changes in climate in
%U http://www.hindawi.com/journals/jmb/2011/406812/