Practice Questions: Essay topics
1.) The biological communities of lakes have often between greatly impacted by human activities,
and these can lead to declines in water quality associated with excessive algal through both
bottom-up and top-down mechanisms. Explain the difference between these two mechanisms,
the types of human induced changes that lead to them, and how one might distinguish between
them using characteristics of the food web.
2.) The river continuum concept had a major effect on our view of biological processes in rivers,
their links to the underlying physical environment, and the way we study them and compare
them to each other. Explain the concept, and show how and why it gave rise to new ideas,
methods and approaches.
3.) Fisheries managers typically use population based models to attempt to make decisions
regarding sustainable exploitation. However, populations of organisms are “embedded” within
complex ecosystems and their carrying capacities and rates of increase are determined by
interactions with other species and with the physical environment. Explain how the parameters
of fish population models can be influenced by community interactions and how these
interactions should influence the decisions that fish managers make.