Discussion of coral reef ecosystems and human impacts by Jean Pierre Ledee, CIAM 6117

1. Reef Ecosystems And Their Decline
Jean Pierre Ledee
CIAM 6117 – 0U1
Prof. Loretta Robertson, PhD

2. OVERVIEW
• ECOSYSTEM
• CURRENT DANGERS
• CLIMATE CHANGE
• BLEACHING
• OVERFISHING
• PUERTO RICO
• REMEDY
• QUESTIONS
• REFERENCES

3. ECOSYSTEM
• FOR MILLIONS OF YEARS, THE
REEFS HAVE BEEN IN A STEADY
BALANCE BETWEEN ITS
ENVIRONMENT IN CHEMICAL AND
PHYSICAL FORM.

4. CLIMATE CHANGE
• WARMER WATER TEMPERATURES
BROUGHT ON BY CLIMATE CHANGE
STRESS CORALS BECAUSE THEY ARE
VERY SENSITIVE TO CHANGES IN
TEMPERATURE.
• IF WATER TEMPERATURES STAY HIGHER
THAN USUAL FOR MANY WEEKS, THE
ZOOXANTHELLAE THEY DEPEND ON
FOR SOME OF THEIR FOOD LEAVE
THEIR TISSUE.
• WITHOUT ZOOXANTHELLAE, CORALS
TURN WHITE BECAUSE
ZOOXANTHELLAE GIVE CORALS THEIR
COLOR.
• BLEACHED CORALS ARE WEAK AND
LESS ABLE TO COMBAT DISEASE.

5. CLIMATE CHANGE
• MUCH OF THE CARBON DIOXIDE THAT
ENTERS THE ATMOSPHERE DISSOLVES
INTO THE OCEAN.
• THE OCEANS HAVE ABSORBED ABOUT
1/3 OF THE CARBON DIOXIDE
PRODUCED FROM HUMAN ACTIVITIES
SINCE THE 1800’S.
• AS CARBON DIOXIDE IN THE OCEAN
INCREASES, OCEAN PH DECREASES
OR BECOMES MORE ACIDIC.
• WITH OCEAN ACIDIFICATION, CORALS
CANNOT ABSORB THE CALCIUM
CARBONATE THEY NEED TO MAINTAIN
THEIR SKELETONS.

6. CLIMATE CHANGE
Time pH
pH change relative
to pre-industrial
H+ concentration
change
relative to pre-
industrial
Pre-industrial (18th
century)
8.179
Recent past (1990s) 8.104 −0.075 + 18.9%
Present levels ~8.069 −0.11 + 28.8%
2050 (2×CO
2 = 560 ppm)
7.949 −0.230 + 69.8%
2100 (IS92a)[34] 7.824 −0.355 + 126.5%

7. CLIMATE CHANGE

8. CLIMATE CHANGE
• BLEACHING

9. OVERFISHING
• ALL ANIMALS THAT ARE FUNDAMENTALLY INTEGRAL TO
THE REEFS MAKE UP A CHAIN THAT STOPS WORKING
CORRECTLY IF ONE OF THE COMPONENTS IS MISSING.
• EACH ANIMAL FEEDS ON OTHER ANIMALS AND IS AT THE
SAME TIME FOOD FOR EVEN GREATER ONES.
• GENERALLY, LARGE CARNIVOROUS ANIMALS FEED ON
THE ONES THAT DIRECTLY EAT PARTS OF THE CORALS.
THIS MAINTAINS A WORKING BALANCE BETWEEN ALL.

10. OVERFISHING

11. OVERFISHING
• THE INTRODUCTION OF HUMANS TO
THE EQUATION HAS GREATLY
AFFECTED THIS FLOW.
• BY OVERFISHING SPECIFIC SPECIES
OF FISH, WE GREATLY UNBALANCE
THE FOOD CHAIN IN THE REEFS.
• HUMANS MOSTLY OVERFISH THOSE
THAT ARE HIGH ON THE FOOD
CHAIN BECAUSE OF THEIR SIZE
AND QUALITY OF THE MEAT.

12. OVERFISHING
• THIS IN TURN CAUSES AN INCREASE ON THOSE THAT
FEED OFF OF THE CORALS AND DAMAGES THE
UNDERWATER LIVING HABITAT.
• BY ELIMINATING THE HABITAT, THE ENTIRE CHAIN IS
BROKEN BY DECREASING THE TOTAL POPULATION IN
THE LONG RUN.

13. PUERTO RICO
• BLEACHING
• 1987 - MAJOR BLEACHING IN THE CARIBBEAN
(HIGH TEMPERATURES)
• 1989 – MINOR BLEACHING (HURRICANE HUGO)
• 1990 - MOST SEVERE BLEACHING EVER
EXPERIENCED IN THE WESTERN NORTH ATLANTIC
• 1995 – SEVERE AND WIDESPREAD BLEACHING
THROUGHOUT CARIBBEAN.
• 1998 – STRONGEST BLEACHING EVENT IN PUERTO
RICO

14. PUERTO RICO

15. REMEDY
• HOW TO FIX THE PROBLEM
• BETTER REGULATIONS NEED TO BE
IMPLEMENTED TO CONTROL THE AMOUNT OF
FISHING DONE THROUGHOUT THE WORLD.
• BETTER MANAGEMENT OF THE CURRENT
REGULATIONS SINCE MOST OF THESE ARE
IGNORED OR NOT ATTENDED AS THEY
SHOULD BE.

16. REMEDY
• CREATE MORE UNDERWATER
SANCTUARIES OR PROTECTED
ENVIRONMENTS TO PROMOTE AND
HELP IN THE CREATION OF NEW
REEFS AND EXPANSION OR
HEALING OF CURRENT ONES.
• MAKE THE PROBLEM VISIBLE TO
THE POPULATION SO EVERY
INDIVIDUAL UNDERSTANDS THE
SITUATION AND IS MOTIVATED TO
HELP.

17. QUESTIONS
• CAN THE PROCESS OF CLIMATE CHANGE BE STOPPED? CAN IT
BE REVERSED?
• CAN BLEACHING OF THE CORALS BE FIXED?
• IS THERE A WAY TO ACCELERATE THE GROWTH OF CORALS?
• CAN WE CONTROL OVERFISHING WITHOUT HINDERING THE
GLOBAL ECONOMY?
• IS THERE A WAY TO BETTER PROTECT AND MAINTAIN THE
UNDERWATER HABITAT?

18. • Coral Reefs and Climate Change - How Does Climate Change Affect Coral
Reefs - Teach Ocean Science. (N.D.). Retrieved September 20, 2015.
• The State of Coral Reef Ecosystems of Puerto Rico – National Oceanic and
Atmospheric Administration. Retrieved September 20, 2015.
• Climate Change and Coral Bleaching In Puerto Rico: Efforts and
Challenges – Puerto Rico Department of Natural and Environmental
Resources. Retrieved September 20, 2015.
• Velazco, A. (2003, June 18). Climate Change And Coral Bleaching In
Puerto Rico: Efforts And Challenges. Retrieved September 20, 2015.
• Using Data To Identify Hot Spots And Predict Bleaching Events –
EarthLabs. Retrieved September 20, 2015.
• Meyers, J. (2009, October 12). Global Warming and Coral Bleaching.
Retrieved September 20, 2015.
REFERENCES