Abstract
Sedimentary and water column evidence from 45 boat-accessible and eight backcountry lakes was used to investigate the distribution of Bythotrephes longimanus in northeast Minnesota, USA, and adjacent Ontario, Canada. The results expand the documented range of Bythotrephes in Minnesota from Lake Superior, Island Lake, and Saganaga Lake to Flour Lake, Greenwood Lake, McFarland Lake, Pine Lake, and Caribou Lake as well as to Saganagons Lake in Ontario. The latter three lakes are located in roadless landscapes without motorized boat access. Results confirm that Bythotrephes is no longer present in Boulder Lake or Fish Lake (St. Louis County, Minnesota), providing the first evidence of range compression (extinction following introduction) of this species in North America. Distributional expansion was confined to a corridor along the international border between northeast Minnesota and Ontario. Lakes along the invasion corridor were deeper, more transparent, and had lower chlorophyll concentration, on average, compared to other lakes studied. The pattern of range expansion provided an opportunity to test the predictions of a forecasting model for Bythotrephes occurrence (MacIsaac et al. 2000 Archiv für Hydrobiologie 149: 1-21) based on habitat characteristics. The model predicted 51% of the surveyed inland lakes to be susceptible to invasion, however, only 13% were actually invaded, implying strong dispersal constraints. Application of the forecasting model to a broader set of 179 Minnesota lakes predicted that 41% may be vulnerable to establishment by Bythotrephes based on habitat characteristics, offering an estimate of the state's overall lake susceptibility (i.e., fundamental niche) to invasion. The results of this study provide evidence for the importance of a low-light refuge where Bythotrephes can minimize vulnerability to fish predation as a key habitat feature not considered by the forecasting model.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1367-1379 |
| Number of pages | 13 |
| Journal | Biological Invasions |
| Volume | 8 |
| Issue number | 6 |
| DOIs | |
| State | Published - Sep 2006 |
Bibliographical note
Funding Information:We thank D. Schimpf and three anonymous reviewers for their helpful comments on the manuscript. This work is the result of research sponsored by the Minnesota Sea Grant College Program supported by the NOAA Office of Sea Grant, United States Department of Commerce, under grant No. NOAA-NA16-RG1046. The US Government is authorized to reproduce and distribute reprints for government purposes, not withstanding any copyright notation that may appear hereon. This article is journal reprint No. JR 513 of the Minnesota Sea Grant College Program. This research was also financially sponsored by a University of Minnesota Grant-in-Aid award to D.K. Branstrator. We thank W. Bartsch, D. Brown, S. Crawford, A. Mer-ritt, and W. Reynolds for assistance in the field and lab; The Minnesota Department of Natural Resources for in-kind usage of a boat and equipment; and The Minnesota Pollution Control Agency for compiling lake data.
Keywords
- Bythotrephes longimanus
- Diapausing eggs
- Dispersal vectors
- Habitat characteristics
- Sediment remains
