1. Coral Reefs: The End?

2. Oceanography in the News New Species Discovered
A Marine Sanctuary
French Frigate Shoals, NW Hawaiian Islands--100 new species discovered (from Oct 31, 2006;
And from October, 2007; many new species discovered in biodiversity hotspot--Celebes Sea, off Indonesia

3. Note orange zone and compare to coral reef distribution in next slide
Red = warm currents / Black = cold currents / Orange = water of 20°C or more
Note orange zone and compare to coral reef distribution in next slide

4. Orange = atolls / Red = fringing reefs / Green = barrier reefs

5. Energy Flow in Reefs The trophic pyramid for coral reef ecosystems
Diverse, mostly small organisms
Phytoplankton play a minor role!

6. Australia - Great Barrier Reef
100 Km

7. Barrier Reef

8. General model of a platform-margin barrier reef presented by James (1983).

9. Algal ridge
                                              

10. Back reef
Reef crest
Fore reef

11. 1

12. back reef seascape branching coral

13. Acropora palmata : Front reef

14. 2

16. Unhealthy signs
Coral “black band” disease (possibly a virus or bacterial infection) kills coral tissue, especially if corals are already under stress for some other environmental factor.
The Crown-of-Thorns starfish can wipe out huge tracts of coral reef. These occur in the western Pacific Ocean and proliferate rapidly when predators are somehow affected (human activity?)

17. Corals in Decline
Many coral reef areas are in decline. Is this natural (have we been looking carefully for long enough?)? Or is is it anthropogenic in origin?
Beautiful appearing “white” corals are, unfortunately, not healthy
Upper panel shows “black band” disease progressing, while the lower panel is a brain coral that is “bleached”--expelled its zooxanthellae (?) Both in Florida reef tracts.
Images courtesy Gene Shinn, USGS

18. Unhealthy Signs
Parrot fish eating blue-green algae which is growing over coral
Below, urchins graze over coral heads (dead)

19. Some Potential Contributors to Coral Reef Demise
Urbanization brings additional problems
Such as:
sediment (from development, agriculture) influx and
excess nutrients (effluents from sewage treatment, septic systems)
Overfishing (note: a general problem with popularity of reef fish for aquaria)
USGS, Hawaii

20. The Florida Keys
wetlands
Florida bay
Florida reef tract
keys

21. Florida Reefs
Florida Reefs--our legacy!

22. Just to Add to the Corals’ Woes
Eugene Shinn, a USGS scientist, proposed recently that the ubiquitous African dust blowing westward off the Sahara might be responsible for some coral diseases (soil-borne microbes that infect polyps). Thus, humans may not be entirely responsible for the demise of coral reefs.
And there is more in Section 7…onward