Measuring the ecological impacts of introducing Arctic charr to sub-Arctic lakes

Anadromous Arctic charr were introduced near the village of Kuujjuaq, Nunavik, and food web impacts were assessed due to this introduction. Stable isotope ratios (C and N) were measured from key resident fish species and used as inferential food web tools to determine impacts. Mean δ13C and δ15N of resident pelagic and littoral and fish species were assessed for changes among years, and were used to calculate quantitative food web metrics providing insight into overall trophic diversity and redundancy. It was predicted that key resident fish species with overlapping resource use with juvenile Arctic charr and potential predatory species such as lake trout would change their measured isotopic ratios to reflect the addition of Arctic charr to the lake, subsequently increasing overall trophic redundancy, vertical food web length, and lake trout omnivory. Significant changes were seen in δ13C of cisco, and δ15N of lake trout, round whitefish and lake chub among years, however these changes were not unidirectional in relation to the introduction. Further, no significant post-introduction changes were seen in lake trout omnivory or in quantitative food web metrics, indicating that changes in mean isotopic ratios may be a reflection of natural variability rather than impacts from the introduction. An explanation for the lack of ecological impact due to the introduction of Arctic charr is discussed in relation to the open niche concept, as Arctic charr may be utilizing resources which were previously unused by resident fish species. This explanation is in accordance with the high habitat flexibility or Arctic charr, and the possibility of an open niche present in the lake due to its post-glacial state. Findings from this study indicate that anadromous Arctic charr may be introduced to similar watersheds in the north without negative consequences for resident fish community structure.

Identifier
Source https://www.polardata.ca/pdcsearch/PDCSearchDOI.jsp?doi_id=11255
Metadata Access http://www.polardata.ca/oai/provider?verb=GetRecord&metadataPrefix=fgdc&identifier=11255_fgdc
Provenance
Creator Michael Power; Alyssa Murdoch
Publisher Canadian Cryospheric Information Network
Contributor Polar Data Catalogue
Publication Year 2014
Rights Research programs, CCIN, or ArcticNet take no liability for the use or transmission of this data
OpenAccess true
Contact m3power(at)sciborg.uwaterloo.ca; pdc(at)uwaterloo.ca
Representation
Language English
Format Computer file
Discipline History
Spatial Coverage (-68.400W, 58.400S, -68.400E, 58.400N)
Temporal Coverage Begin 1999-08-01T00:00:00Z
Temporal Coverage End 2013-08-31T00:00:00Z