Skip to Main Content
Geography of invasion in mountain streams: consequences of headwater lake fish introductionsAuthor(s): Susan B. Adams; Christopher A. Frissell; Bruce E. Rieman
Source: Ecosystems. 4(4): 296–307
Publication Series: Scientific Journal (JRNL)
PDF: Download Publication (270 KB)
DescriptionThe introduction of fish into high-elevation lakes can provide a geographic and demographic boost to their invasion of stream networks, thereby further endangering the native stream fauna. Increasingly, remaining populations of native salmonids are concentrated in fragmented headwater refugia that are protected by physical or biological barriers from introduced fishes that originate in the pervasive source populations established at lower elevations. Although fish introduced near mainstem rivers frequently encounter obstacles to upstream dispersal, such as steep slopes or falls, we found that brook trout (Salvelinus fontinalis) dispersed downstream through channel slopes of 80% and 18-m-high falls. Thus, headwater lake stocking provides source populations that may be capable of invading most downstream habitats, including headwater refugia of native fishes. The extent of additional area invasible from lakes, beyond that invasible from down-stream, depends on the geography of the stream network, particularly the density and distribution of headwater lakes and their location relative to barriers inhibiting upstream dispersal. In the thermal and trophic environments downstream of lakes,fish commonly grow faster and thus mature earlier and have higher fecundity-at-age than their counterparts in other high-elevation streams. The resulting higher rates of population growth facilitate invasion. Larger body sizes also potentially aid the fish in overcoming barriers to invasion. Trout introductions to high-elevation headwater lakes thus pose disproportionately large risks to native fishes even when the place of introduction may appear to be spatially dissociated from populations of the native species. Mapping the potential invasible area can help to establish priorities in stocking and eradication efforts.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationAdams, Susan B.; Frissell, Christopher A.; Rieman, Bruce E. 2001. Geography of invasion in mountain streams: consequences of headwater lake fish introductions. Ecosystems. 4(4): 296–307
Keywordsinvasion, dispersal, landscape, demography, conservation, nonnative fish, salmonids, lake, stream
- Movements of nonnative brook trout in relation to stream channel slope
- Have brook trout (Salvelinus fontinalis) displaced bull trout (Salvelinus confluentus) along longitudinal gradients in central Idaho streams?
- Movement of Southern Brook Charr in a North Carolina Headwater Stream
XML: View XML