430 likes | 595 Views
Week 32, Day Two. HW # 107- Complete Coral Reef essay prompt (due Friday ) Chapter 11 Exam Friday Warm up List 3 reasons why coral reefs a re in danger. Warm up Response . C. Homework Response/Check. Did you complete your reading an annotations?. Goals for Today.
E N D
Week 32, Day Two HW # 107- Complete Coral Reef essay prompt (due Friday) Chapter 11 Exam Friday Warm up List 3 reasons why coral reefs are in danger.
Homework Response/Check • Did you complete your reading an annotations?
Goals for Today • Coral Reefs • Facts • Article discussion
Coral Reefs http://tools.coralreef.org/content/ objects/view.acs?object_id=545 http://ourworld.compuserve.com/homepages/ mccarty_and_peters/coral/C-intro.htm
Importance of Coral Reefs • 0.2% of world’s oceans • Habitat for 1/3 of marine fishes • Habitat for tens of thousands of other animals • The rainforests of the oceans
Importance of Coral Reefs • PROTECTION TO COASTLINES • ECONOMIC RESOURCES • BIODIVERSITY • NATURAL BEAUTY
Importance of Coral Reefs • PROTECTION TO COASTLINES • absorb energy of ocean waves • reduce erosion of shoreline • storm damage • flooding
Importance of Coral Reefs • ECONOMIC RESOURCES • Fisheries for food • Fisheries for jobs • Tourism • Building materials • Aquarium trade
Importance of Coral Reefs • BIODIVERSITY • The rainforests of the sea • Genetic diversity • Pharmaceuticals
Importance of Coral Reefs • NATURAL BEAUTY http://sustainableseas.noaa.gov/missions/ florida2/background/coralspawning.html
$375 billion in environmental goods and services Reefs at Risk 1998 (http://www.wri.org/powerpoints/reefswww/sld011.htm
Caribbean reef values(annual net benefits in 2000) • Fisheries: $310 million • Dive tourism: $2.1 billion • Shoreline protection: $0.7-2.2 billion Total: $4.1-4.6 billion
REEFS WORLDWIDE ARE THREATENED 11% of reefs have been lost 16% of reefs severely damaged ~60% of studied reefs threatened by human activities No pristine reefs left
CARIBBEAN REEFS DECLINING 1970s: ~50% coral cover Present: ~10% coral cover =80% reduction in coral cover over last 30 years Gardner et al. 2003 Science 301: 958-960
Threats to coral and coral reefs: 1) Natural 2) Anthropogenic of human origin
Natural disturbances that affect corals and coral reefs? Hurricanes Tsunamis Volcanoes Earthquakes Predators & competitors Bleaching Pathogens
Hurricanes • Physical damage • Smothering • Freshwater poisoning http://www.nhc.noaa.gov/ 1989hugo.html • Destruction of other ecosystems upon • which coral reefs depend
Tsunamis • Physical damage • Erosion • Possible disruption of reproduction and recruitment
Volcanoes • Depends upon where volcano occurs • Heat • smothering and sedimentation http://volcano.und.nodak.edu/vwdocs/ current_volcs/montserrat/montserrat.html
Earthquakes • Little direct impact • Indirect impacts • triggers tsunamis • coastal landslides
Predators • crown of thorns starfish • snails • parrotfish • butterflyfish http://www.aims.gov.au/pages/reflib/ cot-starfish/pages/cot-q07.html http://www.sanctuaries.nos.noaa.gov/pgallery/pgflower/living/fg_living.html
Competitors • algae http://catbert.er.usgs.gov/african_dust/algae.html
Bleaching • Loss of zooxanthellae • causes • higher than usual ocean temperature • sharp changes in salinity • heavy UV light exposure http://ourworld.compuserve.com/homepages/ mccarty_and_peters/coral/Bleach.htm
http://orbit-net.nesdis.noaa.gov/orad/coral_bleaching_index.htmlhttp://orbit-net.nesdis.noaa.gov/orad/coral_bleaching_index.html
Pathogens • Diseases on the rise • new pathogens (8+) • land pathogens (Aspergillus) • occurring at all depths • More susceptible when stressed http://ourworld.compuserve.com/ homepages/mccarty_and_peters/ coral/Bbd.htm
Threats to coral and coral reefs: 1) Natural 2) Anthropogenic of human origin
Anthropogenic threats to coral reefs: Overfishing Development Mining and dredging Recreation
Overfishing • Ecological imbalance http://www.photolib.noaa.gov/reef/reef2570.htm http://tools.coralreef.org/content/objects/view.acs?object_id=545
Overfishing • Ecological imbalance http://catbert.er.usgs.gov/african_dust/events.html
Overfishing • Destructive fishing practices http://oceanworld.tamu.edu/students/coral/coral5.htm http://www.wri.org/indictrs/rrcyanid.htm
Development • Sediment smothering • Freshwater input • Pollutants & nutrients (sewage, pesticides, fertilizer, heavy metals, pathogens)
Development http://www.wcmc.org.uk/marine/data/coral_mangrove/coral.danger.html http://ourworld.compuserve.com/homepages/mccarty_and_peters/coral/c-intro.htm
Development http://www.sanctuaries.nos.noaa.gov/scied/science/habitat/influences.html
Mining for construction materials and dredging • Destruction of reef structure • stirs up sediment
Recreation • Anchors, boats, flippers, hands, feet • Kill animal tissue • Skeleton breakage http://www.sanctuaries.nos.noaa.gov/scied/science/habitat/influences.html
Synergistic effects • interaction of natural changes & human activity • multiple insults
Global climate change • Reduced reef building • Increase in frequency and intensity of hurricanes • Increases in bleaching • Increased in disease
Synergistic effects CORAL DOMINATED ALGAL DOMINATED
JAMAICA OVERFISHING HURRICANE ALLEN 1980 ACROPORA DIE-OFF 1980S DIADEMA DIE-OFF 1983
JAMAICA MORE ALGAE NO GRAZERS LESS CORAL PHYSICAL DAMAGE ALGAL DOMINATED SYNERGISTIC EFFECTS
BUCK ISLAND, ST. CROIX PROTECTION SINCE 1961 ACROPORA DIE-OFF 1980S DIADEMA DIE-OFF 1983 HURRICANE HUGO 1989 HURRICANES MARILYN/LUIS 1995
BUCK ISLAND, ST. CROIX PROTECTION LITTLE OVERFISHING DISEASE PHYSICAL DAMAGE CORAL DOMINATED