NOAA: The Heat is ON! Climate Change and Coral Reef Ecosystems

Transcription

1 LIVE INTERACTIVE YOUR DESKTOP NOAA: The Heat is ON! Climate Change and Coral Reef Ecosystems Coral Bleaching Dr. Mark Eakin Thursday, April 30, 2009

2 Coral Bleaching 101 Presented by Mark Eakin Coordinator, NOAA Coral Reef Watch

3 Outline 1. Climate change 2. Introduction to coral reefs 3. Coral bleaching basics 4. Bleaching surprises 5. What does the future hold? 6. Classroom resources

4 Outline 1. Climate change 2. Introduction to coral reefs 3. Coral bleaching basics 4. Bleaching surprises 5. What does the future hold? 6. Classroom resources

5 Is Climate Changing? Warming of the climate system is unequivocal - IPPC 4th Assessment Report, WG Top-ten warmest years since

6 Carbon Dioxide and Temperature 386 ppm Current CO 2 highest in 650,000 years of ice core data and 24 million years from soil data

7 Carbon Dioxide and Temperature 386 ppm Current CO 2 highest in 650,000 years of ice core data and 24 million years from soil data

8 The Rates are Important

9 The Rates are Important

10 Reality is Following the Worst Projections From IPCC AR WG-1

11 Questions?

12 Outline 1. Climate change 2. Introduction to coral reefs 3. Coral bleaching basics 4. Bleaching surprises 5. What does the future hold? 6. Classroom resources

13 What is a coral reef? Animal Vegetable Mineral

14 What is a coral reef? All of the above!

15 Animal / Vegetable/ Mineral Slide after of Joan Kleypas, NCAR

16 Plant / Animal / Mineral Reef Community Slide after of Joan Kleypas, NCAR

17 What do corals eat? -Like a sea anemone, the polyp captures small prey with its tentacles -Also get nutrition from a symbiotic relationship with zooxanthellae.

18 What are zooxanthellae? Algae Fish Shrimp

19 What are zooxanthellae? Photo: Michael ten Lohuis Algae that live in the coral polyp s surface layer Algae get nutrients and a safe place to grow Corals get many benefits: most of their food oxygen help with waste removal help in building their skeletons

20 Questions?

21 Outline 1. Climate change 2. Introduction to coral reefs 3. Coral bleaching basics 4. Bleaching surprises 5. What does the future hold? 6. Classroom resources

22 What is coral bleaching? Healthy coral Bleached coral Coral bleaching is caused by stress

23 What turns the coral white? Healthy coral with algae Bleached coral with no algae - As a stress response, corals expel the symbiotic zooxanthellae from their tissues - The coral tissue is clear, so you see the white limestone skeleton underneath

24 What will stress a coral and cause bleaching? A. Nutrient enrichment (eutrophication). B. Fish bites. C. Lack of vitamin D. D. High water temperature. E. Too much homework.

25 What will stress a coral and cause bleaching? -High light or UV levels -Cold temperatures -Low salinity from coastal runoff or heavy rain -Exposure to air during very low tides Most important: high water temperature Photos: AIMS and GBRMPA

26 Thermal stress -Corals live close to their thermal maximum limit -If water gets 1 or 2 C higher than the summer average, corals get stressed and bleach -NOAA satellites measure global ocean temperature and thermal stress

27 How warm is too warm? How hot do you think the ocean has to get before corals start to bleach?

28 How warm is too warm? Bleaching threshold temperatures vary from ~27 33 C (81 91 F). Corals from naturally warmer areas are adapted to high temperatures, and have a higher bleaching threshold.

29 Can corals recover? -Yes, if the stress doesn t last too long -Some corals can eat more zooplankton to help survive the lack of zooxanthellae -Some species are more resistant to bleaching, and more able to recover Photos: AIMS and GBRMPA

30 Can corals recover? -Corals may eventually regain color by repopulating their zooxanthellae -Algae may come from the water column -Or they may come from reproduction of the few cells that remain in the coral Jeff Miller, National Park Service

31 Can corals recover? -Corals can begin to recover after a few weeks Jeff Miller, National Park Service

32 Does bleaching kill corals? -Yes, if the stress is severe -Some of the polyps in a colony might die -If the bleaching is really severe, whole colonies might die -Bleaching in Puerto Rico killed an 800-year-old star coral colony in 2005

33 2005 Bleaching in the Virgin Islands National Park Mennebeck Bay Yawzi Point Over 90% bleached Over 60% died Newfound Reef J. Miller (unpublished) South Florida/Caribbean Network I&M Program

34 Questions?

35 Outline 1. Climate change 2. Introduction to coral reefs 3. Coral bleaching basics 4. Bleaching surprises 5. What does the future hold? 6. Classroom resources

36 What else can thermal stress do to corals? Photo: Caroline Rogers, USGS Question: what is something that happens to people when they are highly stressed? Gain weight Get sick Turn orange

37 What else can thermal stress do to corals? Photo: Caroline Rogers, USGS Question: what is something that happens to people when they are highly stressed? Answer: more likely to get sick

38 Bleaching and coral disease -Coral diseases are found around the world -High temperatures and bleaching can leave corals more vulnerable to disease Marilyn E. Brandt, University of Miami -Can quickly kill part or all of the coral colony

39 Hurricanes: a mixed blessing -Hurricanes can cause direct physical damage to coral reefs -However, the storms also cool the water -Hurricane Katrina led to less bleaching in the Florida Keys, Aug Sept 2005

40 Hurricanes: a mixed blessing 2005: Most named storms Most hurricanes Most damage in US The same warm water that causes corals to bleach can also lead to strong hurricanes.

41 Hurricanes: a mixed blessing Sombrero Reef, FL SST (degc) DHW (degc week) Dennis 9 July Katrina 26 Aug Rita 21 Sept Wilma 24 Oct Each passing hurricane in 2005 cooled the water in the Florida Keys.

42 Bleaching and Acidification -Recent study: synergy between ph and warming -Lower ph more bleaching for a given temperature -Ocean acidification may make global warming effects worse Fraction Bleached at 29 C ph 380 ppm ~600 ppm ~1150 ppm Anthony, K.R.N. et al., Ocean acidification causes bleaching and productivity loss in coral reef builders. Proc. Natl. Acad. Sciences 105:45, p

43 Questions?

44 Outline 1. Climate change 2. Introduction to coral reefs 3. Coral bleaching basics 4. Bleaching surprises 5. What does the future hold? 6. Classroom resources

45 A Worldwide Crisis Bleaching has already happened around the world. (map shows all bleaching reports since 1963) Adds to other stress (fishing, pollution, etc.) 19% of reefs have been lost 15% more are under imminent threat

46 Future Warming Coral bleaching threshold Hoegh-Guldberg, Climate change, coral bleaching, and the future of the world s reefs. Marine and Freshwater Research 50(8),

47 Two-part Solution: 1: lower global CO 2 emissions Even if the concentrations of all greenhouse gases and aerosols had been kept constant at year 2000 levels, a further warming of about 0.1 C per decade would be expected. Sea Level Rise from - IPCC 4th Assessment Report, WG1

48 Two-part Solution: 2: increase reef resilience Shade reefs Cool reefs Improve water quality Reduce other stress (pollution, disease) Reduce overfishing

49 Coral Reefs Are Too Valuable to Lose -Not just a nice place to visit on vacation! -Over $375 billion in fish, seafood, tourism, and coastal protection worldwide -0.5 to 1 Billion people directly depend on healthy reefs for their food and livelihood -Highest marine biodiversity in the world

50 The Future of Reefs Is Up To Us A B C Hoegh-Guldberg et al., Coral reefs under rapid climate change and ocean acidification. Science 318,

51 What Can YOU Do? 1. Don t buy jewelry/souvenirs made from coral or other reef animals. 2. Reduce fertilizer use. 3. Be a responsible tourist. 4. Learn more about coral reefs. 5. Spread the word.

52 Questions?

53 Outline 1. Climate change 2. Introduction to coral reefs 3. Coral bleaching basics 4. Bleaching surprises 5. What does the future hold? 6. Classroom resources

54 Satellite Data and Animations (website demonstration) NOAA Coral Reef Watch website provides current conditions, data, Google Earth, etc. Anomaly animation shows ENSO status, etc.

55 Google Earth Fun, interactive tool Also teaches tropical geography! See where conditions are right for coral bleaching right now. Live links to data on the web.

56 Google Earth Fun, interactive tool Also teaches tropical geography! See where conditions are right for coral bleaching right now. Live links to data on the web.

57 Classroom Resources Satellite data/coral bleaching Lesson plans, data activity, tutorial Ocean education Tutorial and online resources for corals Coral Reef Conservation Program Central listing for coral education resources

58 Bleaching 101: summary - Corals are animal, vegetable, AND mineral - Hot water bleaches corals - Corals may die after bleaching - Diseases follow many warming/bleaching stress events -We need to act now to save coral reefs

59 Special Thanks to for Sponsoring Tonight s Web Seminar

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62 National Science Teachers Association Dr. Francis Q. Eberle, Executive Director Zipporah Miller, Associate Executive Director Conferences and Programs Al Byers, Assistant Executive Director e-learning NSTA Web Seminars Paul Tingler, Director Jeff Layman, Technical Coordinator LIVE INTERACTIVE YOUR DESKTOP