Barrons AP Environmental Science

(Marvins-Underground-K-12) #1

  1. (B) It is thought that improvements to the Erie Canal in 1919 allowed sea
    lampreys to spread from Lake Ontario to Lake Erie, and eventually to spread
    to Lake Michigan, Lake Huron, and Lake Superior, where they decimated
    indigenous fish populations in the 1930s and 1940s. Sea lampreys have
    created a problem with their aggressive parasitism on key predator species
    and game fish, such as lake trout. The lake trout is considered an apex
    predator, which means that the entire system relies on its presence to be
    diverse and healthy. With the removal of an apex predator from a system,
    the entire system is affected.

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