Coral Reefs: Biology, Geology & Politics

Let's Play 20 (or so)Questions – EXAM 02

1. What factors will determine the magnitude of the damage on land and on the reef from a particular storm? Where possible, give examples.

2. How do reefs change as we go from the eastern Caribbean (e.g. the Windward Islands) to the northeast Caribbean (e.g., St. Croix and Puerto Rico) to the northern Caribbean (e.g., the Bahamas)? How does the Intermediate Disturbance Hypothesis fit into all of this?

3. A number of the “rules” of coral reef development were broken around Easter Island. Give a couple examples (consider what is “wrong” according to our classic models and what is responsible), and then discuss a) what was responsible, and b) what this tells us about coral reef models.

4. Consider changes in the shallow reef community at Easter Island over the past several decades. What does this tell us about defining “healthy” reefs?

5. What do we mean when we define uniformitarianism as: “the present is the key to the past”?

6. How is a reef built at a geologic scale (i.e., at the whole system level and over longer periods of time)? What should we look for in our search for ancient reefs?

7. Our older models of modern reefs involved “corals growing on the backs of other corals”. Yet, when we look at most ancient reefs we find recognizable reef builders, but they are often broken up and not in life position. What is the carbonate budget, and how does it help to resolve this apparent paradox? Were reefs that much different in the past or have we just been missing something?

8. What is the difference between a bioherm and a biostrome? How would we tell which one we were looking at in an outcrop? What is the significance of this differentiation with respect to understanding the paleo-ecology of a fossil bioherm vs a fossil biostrome?

9. Consider the ever-changing factors over geologic time that were responsible for shifts in reef communities over the past few billion years? Don’t worry about the absolute time frame, but be able to discuss general patterns and the things that drove those patterns over time. Give general examples for some of the major shifts.

10. What are the problems with using modern coral reefs as models for their ancient counterparts, say 50, 100 and 500 million years ago? How might we get by these problems?

11. What is taphonomy and how does it relate to our ability to understand what a particular reef looked like eons ago?

12. What lessons can we take from the geologic past that might help us understand recent environmental decline? What are some of the potential pitfalls in the approach?

13. What is an “extinction”? What factors have been responsible for mass extinctions in the past?

14. What were stromatolites? What is their significance to reef evolution?

15. Why were these lowly “pond slime” able to build reefs? What happen to change that?

16. Why are the modern counterparts of stromatoporoids relegated to deeper water and caves today?

17. How can we use our understanding of modern coral reefs to understand a stromatoporoid reef that existed 350 million years ago?

18. What does it tell us that we had reefs just west of Oberlin in Silurian time?

19. Why did marine organisms build skeletons if it is so costly an activity? Conversely, why didn’t organisms build skeletons 2 billion years ago?

20 . What did the development of the coral-zooxanthellae relationship do for reef builders?

21. Generally speaking, why does sea level rise and fall?

22. What general effects do the tilt of the planet's axis and the shape of its orbit have on weather and climate?

23. What evidence do we have for the past rise and fall of sea level (I need enough detail to show that you generally understand the concept)

24. What effects does sea-level changehave on coral reefs?

25. What are Keep-Up, Catch-Up and Give-Up reefs. How do they relate to the rate of sea level rise (look at the Holocene sea level curve as an example).

26. What are the implications of all this to the future of coral reefs?