Skip to main content

Interaction between hatchery and wild juvenile white-spotted charr Salvelinus leucomaenis in a stream enclosure experiment

Buy Article:

$51.00 plus tax (Refund Policy)

Abstract:

The competitive interactions between hatchery and wild juvenile white-spotted charr Salvelinus leucomaenis were examined in enclosure experiments in a natural stream. A total of 24 enclosures (1·0 × 1·0 × 0·7 m height) were arranged in stream in an array for randomized block design with replicates of three treatments (wild fish only, hatchery fish only, wild plus hatchery fish). Three experiments were conducted in 2006, using different densities and sizes for each experimental trial. When densities in enclosures were controlled to be equal among treatments (4 individuals m−2: substitutive design), wild fish in the presence of hatchery fish had significantly higher growth rates than the wild fish alone treatment. When densities in enclosures were controlled to be 4 individuals m−2 hatchery fish only treatment, 4 individuals m−2 wild fish only treatment and 8 individuals m−2 in the hatchery plus wild fish treatment (additive design), wild fish in the presence of hatchery fish had significantly lower growth rate than the wild fish alone treatment. Hatchery fish in the presence of wild fish also grew significantly slower than the hatchery fish alone treatment. When densities in enclosures were controlled to be equal among treatments (4 individuals m−2) but hatchery fish were 1·1 times longer than wild fish, growth of wild fish in the presence of the larger hatchery fish did not differ significantly from growth of the wild fish alone treatment. These results suggested that relative size of hatchery fish in relation to wild fish and increased fish density are two important factors influencing the growth of wild juvenile S. leucomaenis.

Keywords: Salvelinus leucomaenis; competitive interaction; enclosure; hatchery fish; stocking

Document Type: Regular Paper

DOI: http://dx.doi.org/10.1111/j.1095-8649.2008.01978.x

Affiliations: 1: National Research Institute of Fisheries Science, Fisheries Research Agency, Nikko, Tochigi 321-1661, Japan 2: Chausuyama Natural Museum, Nagano, Nagano 381-2225, Japan

Publication date: September 1, 2008

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Partial Open Access Content
Partial 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