5 Things to Know: Invasive species in the Great Lakes
To mark New York's Invasive Species Awareness Week, we asked Andrea Locke of Buffalo State to answer some questions on the issue. As Coordinator of the Western New York Partnership for Regional Invasive Species Management office, she has all the answers.
Great Lakes Today: How many invasive species are there in the Great Lakes?
Locke: There are approximately 180 invasive species recorded within the Great Lakes. This number includes all known aquatic species as well as some terrestrial plants, but does not include all invasive species found within the Great Lakes Basin. Although many of the species found are similar throughout the Great Lakes, there are many differences as well. Water temperature, depth, connectivity, and how/where species are introduced and how species spread determine the differences between the lakes.
Great Lakes Today: Which one or two are creating the most havoc?
Locke: The species doing the most damage to the Great Lakes are those species that significantly disrupt aspects of the ecosystem that native animals, plants and other organisms depend. These disruptions can be to nutrient cycles and water filtration, food webs or structural diversity that provide different habitats. Although not yet within the Great Lakes, Silver and Bighead Carp would be such species. Another example, currently found within the Great Lakes, would be zebra and quagga mussels.
Great Lakes Today: How did most of the invasives get into the lakes?
Locke: Invasive species are introduced to the Great Lakes a number ways. We call these Pathways of Invasion, and the vast majority of these pathways are man-made or human assisted. A primary Pathway of Invasion for the Great Lakes is ballast discharge. Prior to ballast discharge regulations going into place, which require boats to exchange ballast water prior to entering the Great Lakes Basin, there was a new invasive species established every 6-8 months. After these regulations were put in place, no new species introductions have been linked to ballast water discharge.
However, this is not the only Pathway of Invasion to the Great Lakes. Species are introduced by hitching rides on recreational boats and trailers, through dumping of bait, releasing pets and or aquarium plants, and on construction equipment. Once a species is established, it is able to use natural pathways, such as wind, water, animals, to continue to spread. But the initial introduction is nearly always made by humans.
Great Lakes Today: Have some invasives turned out to be beneficial to the lakes?
Locke: By definition, an invasive species is not beneficial. There are many non-native species that have been introduced to the Great Lakes Basin and these can have little to no impact, or be beneficial. An invasive species is one that is non-native to the ecosystem in question and causes, or is likely to cause, environmental or economic harm, or harm to human health. Some species are considered more harmful than others, depending on value judgments. However, the negative impacts of invasive species are real and far outweigh any perceived benefit some may claim.
Great Lakes Today: Is there a species that keeps you up at night with worry?
Locke: Killer shrimp, silver and bighead carp, and water hyacinth are all species not yet established in the Great Lakes that have the potential to cause severe impacts.
WNY PRISM is focused on improving the effectiveness of invasive species management and increasing awareness of invasive species issues across an eight-county region. The organization is hosted by the Great Lakes Center, as a sponsored program of the Research Foundation for Buffalo State.