11th ICRS Abstract book - Nova Southeastern University
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11th ICRS Abstract book - Nova Southeastern University

11th ICRS Abstract book - Nova Southeastern University 11th ICRS Abstract book - Nova Southeastern University

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Poster Mini-Symposium 25: Predicting Reef Futures in the Context of Climate Change 25.1157 Potential Impacts Of Anthropogenic Climate Change On Coral Reefs And Mangroves In Madagascar Katie ARKEMA* 1 , Jameal SAMHOURI 2 1 Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Seattle, WA, 2 Northwest Fisheries Science Center, NOAA Fisheries, Seattle, WA Madagascar is best known for its terrestrial biodiversity and endemism. However, the approximately 6,000 km of Malagasy coastline are also home to an impressive diversity of marine habitats and species. Coral reefs and mangroves, which are expected to be particularly vulnerable to anthropogenic climate change, occur along much of the country’s coastline. World Wildlife Fund (WWF) and Conservation International (CI) are assessing the vulnerability of coral reefs to increases in ocean temperature, sea level rise, changes in water chemistry, and other potential impacts of climate change on Malagasy marine ecosystems. One aspect of this assessment is a synthesis of peer reviewed literature to determine current knowledge about the geographic distribution of various habitats and identify research explicitly examining the impacts of climate change on ocean ecosystems in Madagascar. We found very few papers with the objective to explore potential impacts of climate change on Madagascar marine ecosystems; however, the consensus view based on recent field surveys is that Madagascar’s coral communities are healthy relative to other areas in the western Indian Ocean. Nevertheless, some areas of Madagascar were heavily impacted by the 1998 El Nino associated bleaching event and many corals could die if such intense bleaching events occur in the future. Furthermore, the literature indicates that coral reefs and mangroves extend along >3,500 km of coastline, including the entire west coast and parts of the north and central east coast. The southwestern coast of Madagascar is heavily populated and much of the country’s rivers drain to the west, dumping sediments, altering salinity levels and increasing turbidity. Although Malagasy reefs are relatively healthy now, our review suggests that they could be particularly vulnerable to anthropogenic climate change in part because of the potential for global warming to interact with other stressors already impacting Madagascar coastal ecosystems. 25.1158 Coral Mortality And Recovery On A Jamaican North Shore Reef Following The 2005 Caribbean Region Bleaching Event Peter GAYLE* 1 , Nigel WALTHO 2 , Bernadette CHARPENTIER 3 1 Centre for Marine Scences - UWI, Discovery Bay Marne Laboratory, St. Ann, Jamaica, 2 Biology, Carelton University, Ottawa, ON, Canada, 3 Research & Development, DUWATECH, Ottawa, ON, Canada In September 2005, extensive coral bleaching was observed on the north coast of Jamaica which occurred in the wake of elevated sea surface temperatures observed in the Caribbean region during the summer of that year. The local impact of this region-wide bleaching event was monitored over a two year period commencing in November 2005. Reefs at Dairy Bull, Rio Bueno and Discovery Bay on Jamaica’s north shore were surveyed using photo transects. The purpose of this study was to determine the extent of the coral bleaching at all sites and to assess species specific mortality and recovery as a function of abundance, time and depth. Bleached and healthy corals (220) were tagged at depths ranging between 8.5m and 36.6m and their condition monitored over time. The mean incidence of bleaching at all three locations decreased from 60.4% (±23.5 SD) to 22.2% (±12.9 SD) during the monitoring period. Initial bleaching observed on the Discovery Bay west fore reef was 63.9% (±15.5 SD) for shallow water (8.5m) in contrast to the 80% (±5 SD) bleaching observed at 24.4m and 36.6m depth. By August 2006, the numbers had decreased to 10.3% (±7.3 SD) for the shallow and 17.6% (±2.1 SD) for deep corals. Complete or partial mortality of tagged corals in shallow water was 21% and 14% for corals tagged at deeper sites. Agaricia and Montastrea spp. were most affected in shallow water. At depth, A. grahamae was most affected by bleaching. Montastrea spp. appeared more robust whereas the Porites spp. were less hardy than their shallow water counterparts. Further studies are required to investigate the relationship, if any, between depth and the resilience and ability of various coral species to withstand the impacts of repeated bleaching events. 25.1159 Coral Bleaching And Spatio-Temporal Variation Of Thermal Stress in Shiraho Fringing Reef Of Ishigaki Island, Southwest Japan Kazuo NADAOKA* 1 , Takahiro YAMAMOTO 2 , Kazuma ARISAKA 2 , Yuji MAEDA 2 , Shunsuke MOTOOKA 2 , Hajime KAYANNE 3 , Satoshi MAEKAWA 4 , Enrico PARINGIT 5 1 Department of Mechanical and Environmental Informatics, Tokyo Institute of Technology, Tokyo, Japan, 2 Tokyo Institute of Technology, Tokyo, Japan, 3 University of Tokyo, Tokyo, Japan, 4 WWF-J, Okinawa, Japan, 5 University of the Philippines, Quezon, Philippines Significant coral bleaching occurred in theYaeyama islands southwest Japan in 2007 summer. To examine detailed characteristics of spatio-temporal variation of thermal stress in a reef and their relationship to the coral bleaching, we made a field survey at Shiraho, a well-developed fringing reef located in the southeast coast of Ishigaki island, in 2007 summer by deploying data loggers of water temperature at 23 points in the reef and 1 point outside the reef. The data was analyzed and compared with the data in 2003 summer obtained by a similar field survey at the Shiraho reef. We made also computational analyses of water temperature variation both in time and space around the reef based on a hydrodynamic and thermal transport model. Besides we performed satellite image analyses to detect coral bleaching distribution in more detail. In 2007 the daily mean temperature outside the reef was around 29°C until July 20 and then rose up to 30.5°C in late July. In the reef the daily mean temperature rose up to about 33.5°C in late July and even the daily lowest temperature exceeded 30°C in the wide area of the reef. Concurrently with this trend of the water temperature in the reef, the coral beaching started to develop extensively in late July. Obviously the significant water temperature elevation indicates the importance of local thermal effects due to shallow topography. Moreover the numerical simulation analysis clarified that the water temperature increase in the reef was augmented by an atmospheric effect; i.e., in late July 2007 the wind became so small that the latent heat flux to the air was decreased. The spatial distribution of the coral bleaching in the reef was found well correlated with the thermal stress distribution, which was appreciably influenced y the local hydrodynamic circulation. 25.1160 Investigating Spatial Variation in Coral Recruitment With Respect To Temperature Along The Southern Coast Of St. John, Us Virgin Islands Daniel GREEN* 1 , Peter EDMUNDS 1,2 1California State University, Northridge, CA, 2California State University, Northridge Studying the effects of physical environmental factors on scleractinian corals has been popularized by the increased frequency of thermal bleaching, however few studies have documented the effect of temperature on coral recruitment. The goals of this study were to test for kilometer-scale variation in seawater temperature and coral recruitment on the southern coast of St. John, US Virgin Islands, and to explore the extent to which temperature might be influencing coral recruitment. To measure temperature and recruitment, a logging thermistor and settlement tiles were deployed at 5-6 m depth at 10 sites in August 2006. Thermistors and settlement tiles were replaced and analyzed every six months in order to capture seasonal variation in biological and physical events. The two sampling periods occurring between August 2006 and July 2007 revealed strong east-to-west relationships in temperature and densities of coral recruits, which is likely a result of the prevailing westward water current. In both sampling periods, the abundance of coral recruits differed significantly among sites, with mean densities declining from ≈ 1.7 recruits tile-1 in the east, to ≈ 0.4 recruits tile-1 in the west. Seawater temperature also varied significantly among sites over both sampling periods, and this effect was reflected in greater daily variation in temperature at western sites compared to eastern sites. Together, through a significant negative correlation between daily variation in temperature and coral recruitment, these results suggest that small-scale variations in temperature are associated with the rate of coral recruitment in St. John. If this relationship applies to larger spatial scales, then it might provide insights into the causes of variation in coral recruitment throughout the Caribbean. 553

Poster Mini-Symposium 25: Predicting Reef Futures in the Context of Climate Change 25.1161 Combined Model Assessment Of Geographic Patterns in Warming Rates On Coral Reefs Through 2050 Lauren FRANCK* 1 , Andrew BAKER 1 , Amy CLEMENT 2 1 Marine Biology and Fisheries, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, 2 Meteorology and Physical Oceanography, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL Climate change is profoundly affecting coral reef ecosystems worldwide, but the likely scale of future impacts is still unknown. Much of the uncertainty stems from differences among climate models and different scenarios for future increases and/or management of greenhouse gases. Recent studies have shown that using the average result of several popular climate models outperforms any single model in isolation. We used this approach to identify reef areas likely to experience significantly less warming than average ("Reefs of Hope") over the next 50 years. We combined the results of 20 coupled Atmosphere- Ocean General Circulation Models (AOGCMs), including GFDL, NCAR, and Hadley, to project warming trends in the tropical-subtropical oceans (40˚N to 40˚S) with a spatial resolution of one degree and a temporal resolution of one month. We then calculated Degree Heating Months (DHMs) for each year, using the maximum mean monthly climatology of the current decade (2001-2010) as a baseline. Annual DHM values were calculated as the sum of all monthly positive temperature anomalies, compared to monthly baseline means. These values were used to construct maps that forecast bleaching pressure in the world's coral reef regions from 2010 to 2050. Annual probability maps for DHM>3 (mild bleaching pressure), DHM>5 (moderate) and DHM>7 (severe) were produced. Overall, warmer latitudes warm fastest. We identified certain areas that are particularly threatened by rapid warming, including the Pacific equatorial belt (Line Islands and Marquesas), and parts of southeast Asia (Bali and Malaysia) and west Africa (Ivory Coast). In contrast, certain areas are projected to experience warming rates that are considerably lower than expected for that latitude. These areas include the tropical western Atlantic (Bermuda, the Florida Keys and the Caribbean) and parts of the far eastern Pacific (Galápagos Islands). This approach may help forecast the survival trajectories of reefs worldwide and determine conservation priorities. 554

Poster Mini-Symposium 25: Predicting Reef Futures in the Context of Climate Change<br />

25.1161<br />

Combined Model Assessment Of Geographic Patterns in Warming Rates On Coral<br />

Reefs Through 2050<br />

Lauren FRANCK* 1 , Andrew BAKER 1 , Amy CLEMENT 2<br />

1 Marine Biology and Fisheries, Rosenstiel School of Marine and Atmospheric Science,<br />

<strong>University</strong> of Miami, Miami, FL, 2 Meteorology and Physical Oceanography, Rosenstiel<br />

School of Marine and Atmospheric Science, <strong>University</strong> of Miami, Miami, FL<br />

Climate change is profoundly affecting coral reef ecosystems worldwide, but the likely<br />

scale of future impacts is still unknown. Much of the uncertainty stems from differences<br />

among climate models and different scenarios for future increases and/or management of<br />

greenhouse gases. Recent studies have shown that using the average result of several<br />

popular climate models outperforms any single model in isolation. We used this approach<br />

to identify reef areas likely to experience significantly less warming than average ("Reefs<br />

of Hope") over the next 50 years. We combined the results of 20 coupled Atmosphere-<br />

Ocean General Circulation Models (AOGCMs), including GFDL, NCAR, and Hadley, to<br />

project warming trends in the tropical-subtropical oceans (40˚N to 40˚S) with a spatial<br />

resolution of one degree and a temporal resolution of one month. We then calculated<br />

Degree Heating Months (DHMs) for each year, using the maximum mean monthly<br />

climatology of the current decade (2001-2010) as a baseline. Annual DHM values were<br />

calculated as the sum of all monthly positive temperature anomalies, compared to<br />

monthly baseline means. These values were used to construct maps that forecast<br />

bleaching pressure in the world's coral reef regions from 2010 to 2050. Annual<br />

probability maps for DHM>3 (mild bleaching pressure), DHM>5 (moderate) and<br />

DHM>7 (severe) were produced. Overall, warmer latitudes warm fastest. We identified<br />

certain areas that are particularly threatened by rapid warming, including the Pacific<br />

equatorial belt (Line Islands and Marquesas), and parts of southeast Asia (Bali and<br />

Malaysia) and west Africa (Ivory Coast). In contrast, certain areas are projected to<br />

experience warming rates that are considerably lower than expected for that latitude.<br />

These areas include the tropical western Atlantic (Bermuda, the Florida Keys and the<br />

Caribbean) and parts of the far eastern Pacific (Galápagos Islands). This approach may<br />

help forecast the survival trajectories of reefs worldwide and determine conservation<br />

priorities.<br />

554

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