Skip to main content

Upstream movement by nonnative brook trout (Salvelinus fontinalis) promotes invasion of native cutthroat trout (Oncorhynchus clarki) habitat

Buy Article:

$50.00 plus tax (Refund Policy)

Abstract:

To understand how immigration and emigration influence the processes by which invading nonnative brook trout (Salvelinus fontinalis) displace native cutthroat trout (Oncorhynchus clarki), we studied trout movement in long segments of three mountain streams in Colorado during 1999–2001. Over 3500 trout were captured and marked at weirs and during electrofishing, both within and downstream of stream segments. Nearly 80% of brook trout captured at weirs were moving upstream, whereas almost 65% of cutthroat trout were moving downstream. Brook trout movements peaked in early summer and again in fall. Brook trout immigration rates from downstream source populations were high, and in one stream, invaders repopulated a segment where they were removed within 8 months. Immigrant brook trout were typically mature adults in similar body condition to the general population. Brook trout immigrated from a range of distances, with local movement within 250 m more frequently detected, but fish also moved from many distances up to 2 km away within a summer. Brook trout encroachment and invasion was characterized by a wave of local movement exerting biotic pressure on the downstream limit of the cutthroat trout population and jump dispersers moving upstream beyond the invasion front promoting rapid population spread.

Nous avons suivi en 1999–2001 les déplacements des salmonidés sur de longs segments de trois cours d'eau de montagne au Colorado pour comprendre comment l'immigration et l'émigration influence les processus par lesquels l'omble de fontaine (Salvelinus fontinalis), une espèce envahissante non indigène, déplace la truite fardée indigène (Oncorhynchus clarki). Nous avons capturé et marqué plus de 3500 poissons près de barrages et lors de pêches électriques dans les segments étudiés ou en aval de ceux-ci. Près de 80 % des ombles de fontaine capturés aux barrages se déplaçaient vers l'amont, alors que presque 65 % des truites fardées se dirigeaient vers l'aval. Le déplacement des ombles de fontaine était maximal au début de l'été et à l'automne. Les taux d'immigration des ombles de fontaine à partir des populations de l'aval sont élevés et, dans un cours d'eau, les ombles ont recolonisé en moins de 8 mois un segment d'où ils avaient été éliminés. Les ombles immigrants étaient généralement des adultes matures dont la condition physique correspondait à celle de la population en général. Les ombles provenaient de points de distances variables; des déplacements locaux de moins de 250 m étaient fréquents, mais certains poissons s'étaient déplacés de points éloignés jusqu'à 2 km au cours d'un été. L'empiètement et l'invasion de l'omble de fontaine se caractérisent par une série de déplacements locaux qui exercent une pression biotique sur la limite aval de la répartition de la population de truites fardées; de plus, certains ombles se dispersent par bonds, se déplaçant loin vers l'amont au-delà du front d'invasion, provoquant ainsi une expansion rapide de la population.[Traduit par la Rédaction]

Document Type: Research Article

Publication date: December 1, 2003

More about this publication?
  • Published continuously since 1901 (under various titles), this monthly journal is the primary publishing vehicle for the multidisciplinary field of aquatic sciences. It publishes perspectives (syntheses, critiques, and re-evaluations), discussions (comments and replies), articles, and rapid communications, relating to current research on cells, organisms, populations, ecosystems, or processes that affect aquatic systems. The journal seeks to amplify, modify, question, or redirect accumulated knowledge in the field of fisheries and aquatic science. Occasional supplements are dedicated to single topics or to proceedings of international symposia.
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Terms & Conditions
  • Sample Issue
  • Reprints & Permissions
  • Ingenta Connect is not responsible for the content or availability of external websites
nrc/cjfas/2003/00000060/00000012/art00008
dcterms_title,dcterms_description,pub_keyword
6
5
20
40
5

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more