2008 Mock Exam - Marine Ecology 160; page 1
The questions on the exam will come from the questions listed below
Questions from reading and discussion section (1 - 3 will be on exam)- 5 or 10 points each
Reading - Hughes 1994
According to Hughes, what is the effect (direct or indirect) of heavy fishing in the Caribbean on the abundance of:
1) Diadema
2) Algae
3) Corals
What are two other factors (besides fishing) which may have affected the abundance of (any of) these populations?
Reading – Warner 1984
Explain the following terms in relation to mating strategies:
a. protogyny
b. protandry
c. simultaneous hermaphroditism
When is a change of sex favored in sequential hermaphroditism? (You can give an example if it helps you to
explain the answer to this question)
Reading Gaines and Bertness
Gaines and Bertness were interested in determining the importance of local retention of larvae in explaining
population dynamics of barnacle populations. What was their conclusion and what was the basis of this conclusion?
Reading – Harvell 1982
Harvell demonstrated that spines are induced in bryozoan colonies by a nudibranch predator. She states that this
interaction is one of the few examples of coevolution in the ocean. What four factors does she cite to support this
conjecture? What other adaptation would strengthen her argument for coevolution (either one discussed in section or
a new one)?
Reading – Doherty 1983
Doherty manipulated the presence of the damselfish, P. wardi, on patch reefs and compared recruitment (density of
recruits) of larval P. wardi to patch reefs with and without residents. What was the result of these manipulations?
What did he conclude and what are the broader implications of these results in terms of what limits the size of reef
fish populations?
Reading – Paine 1966
What role did the seastar, Pisaster, play in influencing diversity in the rocky intertidal? How did Paine determine
this? In theory, how does keystone predation act to maintain or increase diversity? What sort of conditions are
necessary for a predator to have such an effect on a community?
Reading – Keough and Downes 1982
Explain the differences between recruitment and settlement. Why might measures of these two processes for the
same species differ?
Reading- Ebert and Russell 1988
Ebert and Russell looked at the relationship between the size frequency distribution of purple sea urchin populations
and the location of these populations along the coast. What was the pattern that they found and what was their
explanation for this pattern?
Reading – Connell 1978
Give examples of two non-equilibrial and two equilibrial hypotheses to explain the maintenance of species diversity.
Describe each of your examples thoroughly (i.e. rationale, assumptions, predictions of each hypothesis).
2008 Mock Exam - Marine Ecology 160; page 2
Compare and Contrast (5 -7 will be on exam) - 6 points each - (should be able to define each term (can be
graphical), give example of each and show how each member of the pair differs.
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
17)
18)
19)
Hypothesis vs. theory
Replication vs. psuedoreplication
Population vs. species
Exponential (Malthusian) vs. logistic growth
Settlement vs. recruitment
Interference vs. exploitation competition
Density-dependent vs. density-independent mortality
Equilibrial vs non-equilibrial models of community organization
Proportional vs. switching vs. keystone predation
Deterministic vs. stochastic models of community organization
Protandry vs. protogyny
Lottery hypothesis vs. storage effect
Fundamental vs. realized niche
Species diversity vs. species richness
Early vs. late successional species (traits of)
Closed vs. open populations
Null vs. alternative hypotheses
Inductive vs. deductive reasoning
Dispersal vs. dispersion
Short Answer Questions (3 - 5 will be on the exam) - 10 points each
1.
Define “statistical power” and describe the relationship between statistical power and (1) alpha, (2) magnitude
of effect (effect size), and (3) level of replication.
2.
Describe the process of science from a Popperian perspective.
3.
In theory, what is the relationship between diversity and disturbance? Describe the basis for the relationship.
Give an example that supports the theory.
4.
Describe how succession can lead to loss of diversity and what general process may lead to increased diversity.
5.
What is the logic of experimental controls? You may use examples to support your answer.
6.
List and describe four mechanisms that may act to increase species diversity.
7.
Define stability in terms of resistance, resilience, elasticity and amplitude.
8.
Under what conditions are larval (behavioral) cues adaptive (you may use a figure as part of your answer)?
9.
Gaines and Roughgarden concluded that rockfish predation affected settlement by the barnacle species Balanus
glandula. Describe their experimental results that led to this conclusion.
10. Describe the experiment and the reasoning used by Grosberg to conclude that stratification of larvae in the water
column determined the spatial distribution of Balanus glandula and Balanus crenatus on pier pilings in Santa
Cruz harbor.
11. Describe three oceanographic features that have been shown to influence patterns of larval supply. Give
examples of species whose larvae have been shown to be influenced by each feature.
12. Describe the hypothetical general relationship between settlement and subsequent adult density. Indicate on
your graph the regions that are dominated by density-dependent and density-independent processes.
13. List one physical and one biological process that is important in the following life-history phases of marine
organisms: Reproduction, transport, delivery, settlement, recruitment.
14. What are the three general models of species vertical zonation in the intertidal? Describe each.
2008 Mock Exam - Marine Ecology 160; page 3
15. Describe how Cowen (1985) used otoliths and El Nino to infer patterns of larval sheephead transport and
replenishment of adult populations throughout Baja California and the Southern California Bight.
16. What are the three primary patterns of dispersion (of organisms), what behavioral mechanisms create them, and
how are the patterns identified graphically?
17. Using Jones’ “pluralistic approach” to discerning what model of maintenance of diversity is operating in a
community, describe how you would interpret whether post-recruitment competition is weak or strong, and
whether or not post-recruitment processes modify recruitment patterns.
Essay Questions (1-2 will be on the exam) – 20 points each
1) Menge and others have proposed a set of rules for the importance of various factors in determining the structure of
intertidal communities along a gradient of environmental harshness. These rules can be represented graphically. In
the figure below: (1) label the x and y axes and indicate direction of scale (e.g. does the scale of the x axis increase
as you move from left to right), (2) label each of the three lines. Describe the basis of these rules in the space below
the figure.
2) Use the work of Doty, Connell and Grosberg to describe the evolution and chronology of ideas concerning the
determination of zonation patterns in rocky intertidal communities.
3) Describe and explain the theoretical relationship between dispersal potential, degree of openness of a population,
spatial scale, and stability and population regulation. As part of your answer you should discuss the conditions when
settlement affects adult number.
4) For each of the following four hypotheses generated to explain the maintenance of species diversity (i.e.,
coexistence of competitors), (1) explain the hypothesis, (2) describe its assumptions, and (3) describe its predictions.
A) Niche Diversification
B) Lottery Hypothesis
C) Storage Effect
D) Recruitment Limitation
5) On exposed shores: (1) settlers and adults of species A occur between 0 and 3 m mlw, (2) settlers of species B
occur between -1 and 2 m mlw and, (3) adults of species B occur between -1 and 0 m mlw.
A) Graph the distributions of settlers and adults for species A and B.
2008 Mock Exam - Marine Ecology 160; page 4
B) Propose two hypotheses for the maintenance of the upper and lower limits of the adult distributions of
species A and B (this means 2 for the upper limit of A, 2 for the lower limit of A etc. – 8 total) that are
consistent with the patterns.
C) Propose tests to distinguish between the two competing hypotheses for the upper limit of species B, OR the
lower of species A.
6) Describe how you would design an experiment that would test whether early post-settlement mortality is
density-independent (d-i) or density-dependent (d-d) and if predators influence whether the rate of
mortality is d-i or d-d.