Rising temperatures caused by climatic warming may cause poleward range shifts and/or expansions in species distribution. Tropical reef corals (hereafter corals) are some of the world's most important species, being not only primary producers, but also habitat-forming species, and thus fundamental ecosystem modification is expected according to changes in their distribution. Although most studies of climate change effects on corals have focused on temperature-induced coral bleaching in tropical areas, poleward range shifts and/or expansions may also occur in temperate areas. We show the first large-scale evidence of the poleward range expansion of modern corals, based on 80 years of national records from the temperate areas of Japan, where century-long measurements of in situ sea-surface temperatures have shown statistically significant rises. Four major coral species categories, including two key species for reef formation in tropical areas, showed poleward range expansions since the 1930s, whereas no species demonstrated southward range shrinkage or local extinction. The speed of these expansions reached up to 14 km/year, which is far greater than that for other species. Our results, in combination with recent findings suggesting range expansions of tropical coral-reef associated organisms, strongly suggest that rapid, fundamental modifications of temperate coastal ecosystems could be in progress.
Yentsch, C. S., Yentsch, C. M., Cullen, J. J., Lapointe, B., Phinney, D. A., & Yentsch, S. W. (2002). Sunlight and water transparency: cornerstones in coral research. Journal of Experimental Marine Biology and Ecology, 268.
Reef-building corals throughout the world are considered endangered. The evidence is a decline in coral health and reduced coral cover. Competing hypotheses for the cause of coral loss include removal of grazers, nutrient enrichment, disease, coral bleaching, increase in temperature, and excess light/ultraviolet exposure. We suggest that light limitation as a second order effect of anthropogenic activity (e.g. sediment resuspension and nutrient enrichment) is a valid and tractable hypothesis. This experimental field and laboratory study demonstrates that corals of the Florida reefs are functioning close to the compensation point where respiration (of coral polyp plus zooxanthellae) consumes the products of photosynthesis of the zooxanthellae, with little if any remaining for growth. We extend this work into an optical monograph that is useful for predicting coral loss and recovery. The monograph is designed to elucidate compensation depth for waters of various transparencies.
Young,C.N.,Schopmeyer,S.A.,Lirman, D. (2012).A review of reef restoration and coralpropagation using the threatened genus acropora in the Caribbean and western Atlantic. Bulletin Of Marine Science. 88(4):1075–1098.
Coral reef restoration has gained recent popularity in response to the steady decline of corals and the recognition that coral reefs may not be able to recover naturally without human intervention. To synthesize collective knowledge about reef restoration focused particularly on the threatened genus Acropora in the Caribbean and western Atlantic, we conducted a literature review combined with personal communications with restoration practitioners and an online
questionnaire to identify the most effective reef restoration methods and the major obstacles hindering restoration success. Most participants (90%) strongly believe that Acropora populations are severely degraded, continue to decline, and may not recover without human intervention. Low-cost methods such as coral gardening and fragment stabilization were ranked as the most effective restoration activities for this genus. High financial costs, the small footprint of restoration activities, and the potential damage to wild populations were identified as major concerns,
while increased public awareness and education were ranked as the highest benefits of coral reef restoration. This study highlights the advantages and outlines the concerns associated with coral reef restoration and creates a unique synthesis of coral restoration activities as a complementary management tool to help guide “best-practices” for future restoration efforts throughout the region.
Yucharoen, M. & Yeemin, T. (2012). Effects of coral bleaching and recovery potential of coral reefs at Mu Koh Surin, the Andaman Sea. Proceedings of the 12th International Coral Reef Symposium, Cairns, Australia, 9-13, 9B.
Elevated seawater temperatures in summer months of 2010 were associated with widespread coral bleaching in the Andaman Sea. The present study examines the impact of coral bleaching and recovery potential of coral reefs at Mu Koh Surin National Park, Thailand. The percentages of dead corals following the bleaching event for all ten study sites were over 50%. The highest percentage of coral mortality was at Hin Pae (71.3%) while the lowest one was at Ao Tao (53.9%). Most Acropora and Pocillopora colonies were affected at all sites and their mortality rates were very high (>90%). Spatial variation in coral bleaching and subsequent mortality was clearly observed with reflecting differences in depth, reef profile and water flow. The densities of coral juveniles were relatively high (6.1-11.0 juveniles.m-2). The major groups of coral juveniles were also high taxonomic diversity, including Acropora spp., Fungia spp., Favia spp., Favites spp., Goniastrea spp. Platygyra spp. Diploastrea heliopora, Cyphastrea spp., Porites spp., Coeloseris mayeri, Gardineroseris planulata, Pachyseris spp., Ctenactis spp. Lithophyllon sp., Pectinia sp., Turbinaria spp., Astreopora sp., Montipora spp., Pocillopora spp. and Galaxea spp. Certain coral communities at Mu Koh Surin exhibit recovery potential after the coral bleaching event therefore the tourism management plan for protection of these coral communities is urgently needed in order to ensure the sources of coral larvae for coral recovery in the Andaman Sea.