Question

3. Climate change (an abiotic factor) has slowly decreased habitat for the arctic seals. Predict how a reduction in habitat could change the capture efficiency of the killer whales. How would this affect the carrying capacities for both the whales and the seals?
4. If another source of prey were available to the whales, what changes in population size would you expect for the seals and the whales? (4 points)

5. In this lesson, you learned about two patterns of population growth and decline, the sigmoid and peak phenomena. Does the seal and killer whale relationship represent a sigmoid or peak phenomenon? Please provide supporting details. (6 points)

6. What are the limitations of the population dynamics lab? Is the lab activity a realistic representation of an arctic marine ecosystem? Note: Please provide detailed support for your opinion. (8 points)

Answer 1

3.  A reduction in habitat for arctic seals will reduce the population of arctic seals. This will reduce the capture efficiency for killer whales preying on arctic seals because there will be fewer to capture. A reduction in habitat for arctic seals will lower the carrying capacity for arctic seals because there is less habitat. A reduction in arctic seals, the food for killer whales, will reduce the carrying capacity for killer whales, unless there is a substitute source of food. 
4. If there is another source of food for killer whales, the population of killer whales will probably remain the same, if they were at their carrying capacity and their habitat remains the same. If there is another source of food for killer whales, the population of arctic seals will still decrease, because the habitat for arctic seals has decreased, and habitat is independent of predator population. 
5.  The seal and killer whale populations represent a peak graph. More than likely, as seal populations increase, killer whale populations will also increase until there are more killer whales and they are eating all the seals. Then, there will be a period when killer whales are dying of starvation, so their population will decline. When killer whale populations decline, there are fewer whales to eat the seals, so the seal population increases, providing lots of food for the whales. The whales increase their population which decreases seal population and the pattern continues. 
6.  There are many limitations on any simulation. The computer only uses the parameters in the program, so changes in ocean temperature, weather patterns, salinity changes, food supply, habitat, interaction with other species and presence of plants and zooplankton are not considered. All of those can change and change the results.