Study Questions: Final

The following questions cover the material from lecture and readings since Midterm II. The Final will also emphasize marine mammals and the lecture on the last day of classes, even though there are no study questions provided here.

Recall that the final is cumulative, and you will want to study from previous lectures, readings, labs, and exams. (Final exam questions on previous material will emphasize topics already covered on the midterm exams.)

1 List the five major ecological factors influence diversity of a community? Explain "dominance control." How does competition affect species diversity? Why is habitat structure related to diversity? Define disturbance and succession. What are some typical disturbance mechanisms in marine communities?

2 How might predation, parasites, and herbivores decrease diversity? How can they increase diversity? Why are sea otters called Keystone predators? How do they increase diversity?

3 What are some general differences in life styles and habitats of green, red, and brown algae? Which alga is most likely found in the tropics? In northern lattitudes? In kelp beds?

4 Where are Kelp forests and beds found (geographically, depth, substrate, ocean conditions)? How does urchin behavior and abundance affect kelp beds? Why are kelp forests so diverse? What did the experiments show about the role of urchins and otters?

5 Based on the example from kelp forests, under what general conditions do predators enhance diversity? Reduce diversity?

6 What conditions lead to trophic cascades? Hints: What is the ecological role of the kelp? What is the strength of the interactions between consumer and consumed?

7 What are the two common species of sea grasses in the US? What three roles do sea grass beds play in the ecosystem? How do sea grasses affect Atlantic bay scallops? What is causing declines in sea grass beds?

8 What are two marine communities that are dominated by amphibious marine angiosperms? What are the two types of amphibious marine angiosperms? What problems do amphibious marine angiosperms face? What limits the distribution of mangroves? What adaptations do mangroves have for marine living? What is the ecological importance of mangroves?

9 What is the distribution of reef building corals, both geographically and with depth? What essential conditions do corals require? Why do coral reefs show high primary productivity? (Hint: what organisms are the main contributors?) Describe the mutualistic relationship between corals and zooxanthellae. What are the costs and benefits to corals? To zooxanthellae?  What is coral bleaching? What conditions lead to coral bleaching?

10 Why are coral reefs so diverse? Describe the mechanisms explaining diversity in cryptic communities, reef fish, and in the corals themselves. Provide one example that demonstrates each mechanism(e.g., non-transitive competition, larval access and the lottery hypothesis, and disturbance).

11 What happens to the diversity and composition of coral reefs when herbivores are removed (e.g.  Diadema in the Caribbean)?

12 Give an example of founder control (larval access) in determining community diversity. Describe habitat, species, and circumstances that lead to founder control in coral reef fishes.

13 What is the Intermediate Disturbance Hypothesis? Why is diversity highest in the middle stage of succession? Explain examples of this hypothesis from corals.

14 What three physical major factors affect intertidal communities? What stresses does the tide cause? Which part of tide range is the most physically stressful? Which is most biologically stressful? How does predation pressure change along a depth gradient? Why?

15 In general, where are rocky intertidal shorelines found, and what geological processes lead to rocky shorelines?

16 What causes zonation in rocky intertidal communities? What usually sets the upper limits of an organism's distribution? The lower limits? Use the Balanus-Chthamalus example to explain.

17 Why is the rocky intertidal a "dominance controlled" community? Which species is dominant in our region? What processes maintain diversity?  What are the similarities and differences between the ecological effect of Pisaster and mussels? Between sea urchins, sea otters, and killer whales?

18 What are the major foraging types of animals in soft sediment habitats? What are some of the predators, deposit feeders, suspension feeders found on soft-sediments?

19 How does the ecology of salt marshes differ from and resemble seagrasses, kelps, and mangroves? How does facilitation lead to species coexistance in salt marshes, and how does it work? Which communities display strong zonation: mud flats, rocky intertidal, salt marshes?

20 How do exotic species affect native biological communities of marine organisms? Name and describe two damaging exotic species found in our region (where they live, what they have impacted). What are the ecological processes and mechanisms? Illustrate competition, predation, and habitat alteration with examples.

21 How do overexploitative fishing activities alter marine species and communities? Describe two specific mechanisms by which overexploitative fishing can alter communities and ecosystems.

22 How do marine reserves, sanctuaries, and protected areas differ? How do the goals differ? What are the main potential advantages of marine reserves? Have they been demonstrated?