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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24.12.2012 Views

24-50 Gametogenesis in Cultured Versus Wild acropora Intermedia Colonies: Fertilization, Survival, And Oxygen Consumption 10 Years After Fragmentation Nami OKUBO* 1 , Hiromi YAMAMOTO 2 , Fumio NAKAYA 3 , Ken OKAJI 4 1 Yokohama National University (present: Kyoto University), Yokohama, Japan, 2 Okinawa Expo Aquarium, Okinawa, Japan, 3 Ochanomizu University, Tokyo, Japan, 4 CoralQuest Inc, Kanagawa, Japan In the late 1990s, the once prolific Acropora intermedia populations surrounding Okinawa, Japan, dramatically declined because of thermal stress and subsequent bleaching and mortality. Before the bleaching event, 72 fragments of approximately 15 cm in length were collected and transferred to the Okinawa Expo Aquarium. Through growth and repeated fragmentation, these original fragments developed into approximately 100 colonies, which spawned from 1999 to 2006. Here we compare gametogenesis, fertilization, survival, and O2 consumption in the cultured and wild offspring. Cultured A. intermedia had larger oocytes (volume), higher fertilization rates, higher embryonic O2 consumption, and higher survival rates compared to samples from wild colonies. These results suggest that the cultured A.intermedia and their offspring are more fit than wild colonies. Oral Mini-Symposium 24: Reef Restoration 227

Oral Mini-Symposium 25: Predicting Reef Futures in the Context of Climate Change 25-1 Is 500 Ppm Co2 And 2°c Of Warming The 'tipping Point' For Coral Reefs? If So, How Should We Respond? Ove HOEGH-GULDBERG* 1 1 Centre for Marine Studies, University of Queensland, St Lucia, Australia The burning of fossil fuels is driving a rapid increase in the concentration of CO2 in the atmosphere which is expected to exceed 500 ppm in the earth’s atmosphere within 50 years. At this point, tropical sea temperatures will be 2°C warmer than 150 years ago and tropical carbonate ion concentrations will fall below 200 µmol kg -1 . These conditions differ markedly from those seen over the past 420,000 years during which time most extant species and communities evolved. Most importantly, the current rate of change in sea temperature and atmospheric CO2 is 70 and 1,000 times faster, respectively, than the highest rates of change seen in the past 420,000 years. This is outstripping biological responses (adaptation, range migration) and is driving major changes in the distribution and abundance of tropical marine organisms. This paper will discuss scenarios associated with the future of coral reefs with the aim of visualizing the challenges that coral reef managers will face over the next few decades as we approach 500 ppm. The weight of evidence suggests that corals will be rare on tropical reefs which will enter a state of net erosion under atmospheric CO2 concentration of 500 ppm or more. As a result, coral reefs are expected to be less diverse and reef frameworks to start to crumble and deteriorate. How can managers respond to these changes? Are there responses that managers should be taking today in preparation for changes projected a few decades from now? Should we contemplate moving vulnerable species or enriching the genetic diversity of species growing at a particular location? These issues will be discussed at the outset of this mini-symposium which anticipates a lively discussion around what is clearly one of the most important issues facing coral reef scientists and managers. 25-2 Implications For Our Coral Reefs in A Changing Climate Over The Next Few Decades – Hints From The Past 22 Years Alan E. STRONG* 1 , Gang LIU 2 , C. Mark EAKIN 1 , Tyler R. L. CHRISTENSEN 2 , Dwight K. GLEDHILL 2 , Scott F. HERON 1 , Jessica A. MORGAN 2 , William J. SKIRVING 1 1 NOAA Coral Reef Watch, Silver Spring, MD, 2 IMSG at NOAA Coral Reef Watch, Silver Spring, MD The NOAA/NASA Pathfinder sea surface temperature (SST) data from 1985 to 2006 are examined for variability and trends on both sides of the recent 1998 Pacific Decadal Oscillation (PDO) reversal for implications on tropical ecosystems. These twenty-two years of satellite observations reveal some noteworthy shifts that have quite different implications for each major ocean basin. In addition, the data reveal expected increasing SST trends toward higher latitudes, especially in the northern hemisphere, confirming the Intergovernmental Panel on Climate Change (IPCC) projections. Although several regions throughout the tropics have experienced decreasing SSTs over the 22-year timeframe, significantly more regions are showing rising trends. Most notable and worrisome is an obvious shift after the recent PDO reversal from cooling to warming in some specific tropical waters. More promising regions, also identified from our results, are presently experiencing cooling trends and thus decreasing pressure from thermal stress. What will be instructive for the future of our precious coral reef ecosystems is whether the dramatic regional shift in trends since the recent 1998 PDO reversal continues to persist into the second decade of the 21 st Century or evolves into a signal of a changing climate. 25-3 The Elephant In The Reef: Committed Warming And Coral Bleaching Simon DONNER* 1 1 Geography, University of British Columbia, Vancouver, BC, Canada An increase in episodes of mass coral bleaching around the world in recent decades have been attributed to more frequent periods of anomalously warm ocean temperatures. Over the past fifteen years, a number of modeling studies have predicted that, left unchecked, human-induced climate change will further increase the frequency and intensity of these thermal stress events and threaten the survival of most of the world’s coral reef ecosystems. As now near the end of the first decade of the 21st century, the questions need to change. Is the future happening now? How much of this projected climate warming can be avoided? In this presentation, I use analysis of the 2005 coral bleaching event in the Caribbean to discuss the role of human-induced climate change in recent mass coral bleaching events and the effect of “committed” warming on the likelihood of future mass bleaching events. Simulations of background climate variability with the GFDL global climate models suggest that anthropogenic warming may have increased the probability of the 2005 coral bleaching events by an order of magnitude. The thermal stress that cause mass coral bleaching in the eastern Caribbean is expected to become a biannual event in 20-30 years regardless of the emissions scenario, due to the inertia in the climate system and the world economy. Thermal adaptation by corals and their symbionts could delay this forecast until the latter half of the century, possibly enabling time to reduce greenhouse gas emissions and change the climate forecast. Taken together, these results suggest that protecting coral reefs from climate change will require managing local stresses, to increase reef resilience to inevitable future warming, and immediate action to reduce greenhouse gas emissions. 25-4 Climate-Scale Influences On The Development Of Coral Bleaching Conditions in The Great Barrier Reef Scarla WEEKS* 1 , Ana REDONDO-RODRIGUES 1 , Andrew BAKUN 2 1 University of Queensland, Brisbane, Australia, 2 Pew Institute for Ocean Sciences, University of Miami, Miami, FL A suite of available time series indicators of climatic and large-scale oceanographic properties and processes were evaluated with respect to providing (1) an appropriately representative climatological background for studying the factors leading to coral bleaching events, (2) a timeseries record long enough to contain multiple independent realisations sufficient for valid hypothesis tests, and (3) a consistent baseline for normalising higher spatial and temporal resolution data obtained from more recent satellite sensors. These indicator series included NOAA OI SST (1° res., 1982-2007), the NCEP series (barometric pressure, wind, water vapor, air temperature, 1948-2007, 2.5° res.), and the NASA “Photosynthetically Active Radiation” product (9km res., 1997-2007). The study focused on three recent coral bleaching events in the GBR, the 1997-1998 “El Niño”-associated event, the 2005-2006 mild “La Niña”-associated event, and the most severe of the three, the 2001-2002 “ENSO-neutral” event. Preliminary findings include: La Niñas (2005-06 in particular) are characterized by high regional-scale SST, while El Niños (1997-98 in particular) are typified by high solar radiation (PAR) incident on the sea surface. Accordingly, bleaching in the GBR may occur in either ENSO phase. The intense 2001-2002 event featured unusually high levels of both SST and PAR. The “linking factor” in all three major bleaching events was anomalously low wind mixing of the near-surface water column. The actual spatial variability of severe bleaching tends to be on scales smaller than resolved by the available climatic series, and seems to be governed by meso-scale and sub-meso-scale ocean flow. Examples are illustrated with 1-km MODIS satellite imagery. An emerging consensus among climate models suggests that the Pacific trade wind circulation may slow and the Pacific system become chronically more El Niño-like. Thus besides direct greenhouse heating, there are additional El Niño-related possibilities of enhancement of PAR and reduction of near-surface wind mixing. 228

24-50<br />

Gametogenesis in Cultured Versus Wild acropora Intermedia Colonies: Fertilization,<br />

Survival, And Oxygen Consumption 10 Years After Fragmentation<br />

Nami OKUBO* 1 , Hiromi YAMAMOTO 2 , Fumio NAKAYA 3 , Ken OKAJI 4<br />

1 Yokohama National <strong>University</strong> (present: Kyoto <strong>University</strong>), Yokohama, Japan,<br />

2 Okinawa Expo Aquarium, Okinawa, Japan, 3 Ochanomizu <strong>University</strong>, Tokyo, Japan,<br />

4 CoralQuest Inc, Kanagawa, Japan<br />

In the late 1990s, the once prolific Acropora intermedia populations surrounding<br />

Okinawa, Japan, dramatically declined because of thermal stress and subsequent<br />

bleaching and mortality. Before the bleaching event, 72 fragments of approximately 15<br />

cm in length were collected and transferred to the Okinawa Expo Aquarium. Through<br />

growth and repeated fragmentation, these original fragments developed into<br />

approximately 100 colonies, which spawned from 1999 to 2006. Here we compare<br />

gametogenesis, fertilization, survival, and O2 consumption in the cultured and wild<br />

offspring. Cultured A. intermedia had larger oocytes (volume), higher fertilization rates,<br />

higher embryonic O2 consumption, and higher survival rates compared to samples from<br />

wild colonies. These results suggest that the cultured A.intermedia and their offspring are<br />

more fit than wild colonies.<br />

Oral Mini-Symposium 24: Reef Restoration<br />

227

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