Ecosystem Shock:The Devastating Impacts of Invasive Species on the Great Lakes Food Web
Publication Date: October 2004
Publisher(s): National Wildlife Federation
Special Collection: The Joyce Foundation
Keywords: wildlife; invasive species ; ballast dumping
Coverage: United States
“Ecosystem Shock” discusses how invasive species disrupt the entire food web of the Great Lakes. Non-native species such as the alewife, spiny water flea, and zebra mussel have entered the Lakes and have had adverse effects on native species like the lake trout and whitefish. Officials worry that two potentially devastating invasive species, the Asian carp and the snakehead, could also enter the Lakes.
The report documents how non-native species harm the ecosystem, threatening predatory fish at the top of the food web and tiny organisms at its base. At its release, the report cited 162 invasive species that had entered the Great Lakes. On average, one new non-native species finds its way into the Great Lakes every eight months, and the frequency of introductions is increasing, the report says.
The most common way that invasive species enter the Great Lakes is through the ballast water of ocean-going vessels. The report urges action to regulate ballast dumping and research to find the best ways to keep invasive species out and handle those already in the Lakes.