HW # 107- Complete Coral Reef essay prompt (due Friday) Chapter 11 Exam Friday

Warm up

List 3 reasons why coral reefsare in danger.

Week 32, Day Two

Warm up Response C

Homework Response/Check• Did you complete your reading an annotations?

Goals for Today

• Coral Reefs Facts Article discussion

http://ourworld.compuserve.com/homepages/mccarty_and_peters/coral/C-intro.htm

Coral Reefs

http://tools.coralreef.org/content/objects/view.acs?object_id=545

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

http://www.nhc.noaa.gov/1989hugo.html

•Destruction of other ecosystems upon which coral reefs depend

•Freshwater poisoning

•Smothering

Tsunamis

• Physical damage

•Possible disruption of reproduction and recruitment

•Erosion

Volcanoes

• Depends upon where volcano occurs

http://volcano.und.nodak.edu/vwdocs/current_volcs/montserrat/montserrat.html

•smothering and sedimentation

•Heat

Earthquakes• Little direct impact

-coastal landslides

•Indirect impacts-triggers tsunamis

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

• Loss of zooxanthellae

• causes – higher than usual

ocean temperature – sharp changes in

salinity– heavy UV light

exposurehttp://ourworld.compuserve.com/homepages/mccarty_and_peters/coral/Bleach.htm

http://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 stressedhttp://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://tools.coralreef.org/content/objects/view.acs?object_id=545

http://www.photolib.noaa.gov/reef/reef2570.htm

Overfishing• Ecological imbalance

http://catbert.er.usgs.gov/african_dust/events.html

http://oceanworld.tamu.edu/students/coral/coral5.htm http://www.wri.org/indictrs/rrcyanid.htm

Overfishing• Destructive fishing practices

Development• Sediment smothering• Freshwater input• Pollutants & nutrients

(sewage, pesticides, fertilizer, heavy metals, pathogens)

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

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

• interaction of natural changes & human activity

• multiple insults

Synergistic effects

Global climate change

• Reduced reef building• Increase in frequency

and intensity of hurricanes

• Increases in bleaching• Increased in disease

CORAL DOMINATED

ALGAL DOMINATED

Synergistic effects

OVERFISHINGHURRICANE ALLEN 1980

ACROPORA DIE-OFF 1980SDIADEMA DIE-OFF 1983

JAMAICA

MORE ALGAENO GRAZERSLESS CORAL

PHYSICAL DAMAGE

ALGAL DOMINATED

SYNERGISTIC EFFECTS

JAMAICA

PROTECTION SINCE 1961ACROPORA DIE-OFF 1980S

DIADEMA DIE-OFF 1983HURRICANE HUGO 1989

HURRICANES MARILYN/LUIS 1995

BUCK ISLAND, ST. CROIX

PROTECTIONLITTLE OVERFISHING

DISEASEPHYSICAL DAMAGE

CORAL DOMINATED

BUCK ISLAND, ST. CROIX