CP Biology 2015-2016
Viewing Guide to Mysteries of the Great Lakes
Like a giant Rorschach ink blot, the Great Lakes spread out across the northern Midwest and eastern U.S. along the
Canadian border. Deep blue and beautiful from the air, these five freshwater lakes hold the key to untold stories—and
strange phenomena—explored in Mysteries of the Great Lakes. This film will take you on a journey through some of the
most spectacular scenery on Earth, from the headwaters of Lake Superior to the edge of Lake Ontario. You’ll travel
beneath the surface where thousands of shipwrecks—the last major one from close to a century ago—draw the interest of
divers to this day. You will also discover the habitats of sturgeon, caribou, moose, and bald eagles—as well as the Great
Lakes’ importance for the 40 million people who live along their nearly 11,000-mile-long coastline.
1. What are the major categories of freshwater ecosystems?
2. What percentage of the world’s freshwater is contained in the Great Lakes?
3. How has human population growth affected the population of Lake Sturgeon?
4. How many years can female Lake Sturgeon live? How many survive to adulthood?
5. How do scientists study the life history of individual Lake Sturgeon?
6. The Lake Sturgeon population is still under threat. How do community volunteers help decrease the threat?
7. What factors are necessary for successful hatching of the eggs? How are these factors critical to
repopulation? How have these factors been disrupted?
How do scientists track individual fish? What important information have they gathered by tracking the
9. An interesting phenomenon has occurred involving Caribou on the Slate Islands. The caribou began
populating the islands at the beginning of the 20th century. What limiting factor (or population) is absent for
these animals? How has this affected the females in the population? Have the males been affected similarly?
What density dependent factors might affect this population and how?
10. Bald eagles have been successfully reintroduced to many ecosystems around the US, but a mysterious
phenomenon was observed in the Great Lakes region eagle population. Seemingly similar habitats were
not supporting the eagles equally. How did ecologists observe/gather information about the eagles? What did
scientists find after observing nesting pairs in different areas around the Great Lakes?
11. What are “hot spots”?
12. What is meant by the term “biological magnification”?
13. What is a “biological invader” or “alien species”? Name three alien species currently found in the Great
Lakes? How did they travel from their native areas to the Great Lakes? How do these invaders affect the
ecosystem? Can these invaders be controlled or eliminated?
14. After studying the Lake sturgeon for many years, and not successfully reintroducing the species, what
important discovery did the scientists make that helped solve the problem? How did the scientists incorporate
this information into their strategy for repopulation?

Viewing Guide to Mysteries of the Great Lakes