Updated 2024-11-06 20:02:47
Lake Superior -> 10.0 Nuisance Species -> Nuisance Species Spread
Reporting Interval
2017 - 2021
Area
Lakewide
Meeting Target?
Does Not Meet
Indicator Trend
Downward trend
Confidence?
High
10.1.2 No Spread of Non-indigenous Aquatic Species in Lake Superior
Establishment of a new non-indigenous aquatic species in Lake Superior could have enormous impacts on the ecosystem and cost millions of dollars to control. Therefore, a component of the Nuisance Species FCO is to prevent or delay the spread of nonindigenous nuisance species, where feasible. (Horns et al. 2003). The number of species detected outside the range of the previous reporting period were tallied to evaluate if previously detected non-indigenous species are spreading in Lake Superior. The spread of non-indigenous species has increased within Lake Superior since reporting period 1962-1966. A 50% decrease in the number of species spreading was observed between the 2012-2016 and 2017-2021 reporting periods, but it is still unclear whether the decline is a real downward trend or partially stabilizing. Regardless, species are still spreading within Lake Superior and, therefore, the indicator to prevent or delay the spread of nonindigenous species is not being met.
Figure 1. Number of Non-indigenous Species Showing Spreading Events in Lake Superior by Reporting Period.
Methodology
The data was downloaded from the Great Lake Aquatic Nonindigenous Species Information System (https://www.glerl.noaa.gov/glansis/), which is a warehouse of non-indigenous aquatic species encountered in the Great Lakes by numerous agencies and entities. The data was filtered for species considered to be non-native to Lake Superior and for taxonomic groups actively targeted by early detection monitoring programs which included fish, amphipods, bivalves, gastropods, crayfish, and mysids. During the reporting period when each species was first detected, a line was drawn around the locations where the species was discovered with a 15-kilometer buffer around the points to mark the range of each species. For the subsequent reporting periods and for each species, a spreading event was determined if new detections for a known species occurred outside of the previous range. If a spreading event was identified, then a new line was drawn to delineate a new range for that species for evaluation in future reporting periods. The number of species that exhibited spread were tallied for each reporting period.
Other Resources
Environment and Climate Change Canada and the U.S. Environmental Protection Agency. 2022. State of the Great Lakes 2022 Technical Report. Cat No. En161-3/1E-PDF. EPA 905-R22-004. Available at binational.net.
Horns, W.H., C.R. Bronte, T.R. Busiahn, M.P. Ebener, R.L. Eshenroder, T. Gorenflo, N. Kmiecik, W. Mattes, J.W. Peck, M. Petzold, D.R. Schreiner. 2003. Fish-community objectives for Lake Superior. Great Lakes Fish. Comm. Spec. Pub. 03-01. 78 p. Available at http://www.glfc.org/pubs/SpecialPubs/Sp03_1.pdf.
Contributing Author(s)
- Lake Superior Technical Committee -