mccarty_and_peters/coral/C-intro.htm Coral Reefs 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 florida2/background/coralspawning.html

$375 billion in environmental goods and services Reefs at Risk 1998 (

Caribbean reef values (annual net benefits in 2000) Fisheries: $310 million Dive tourism: $2.1 billion Shoreline protection: $ billion Total: $ 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 Science 301:

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 hugo.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 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 cot-starfish/pages/cot-q07.html

Competitors algae

Loss of zooxanthellae causes – higher than usual ocean temperature – sharp changes in salinity –heavy UV light exposure mccarty_and_peters/coral/Bleach.htm

Pathogens Diseases on the rise –new pathogens (8+) –land pathogens (Aspergillus) –occurring at all depths –More susceptible when stressed 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 gov/reef/reef2570.htm

Overfishing Ecological imbalance

students/coral/coral5.htm Overfishing Destructive fishing practices

Development Sediment  smothering Freshwater input Pollutants & nutrients (sewage, pesticides, fertilizer, heavy metals, pathogens)

/data/coral_mangrove/coral.dan ger.html epages/mccarty_and_peters/coral/c- intro.htm Development

Mining for construction materials and dredging Destruction of reef structure stirs up sediment

Recreation Anchors, boats, flippers, hands, feet Kill animal tissue Skeleton breakage /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

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 JAMAICA

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 BUCK ISLAND, ST. CROIX