Winter feeding, growth and condition of brown trout Salmo trutta in a groundwater-dominated stream

William E. French, Bruce Vondracek, Leonard C. Ferrington, Jacques C. Finlay, Douglas J. Dieterman

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

Winter can be a stressful period for stream-dwelling salmonid populations, often resulting in reduced growth and survival. Stream water temperatures have been identified as a primary mechanism driving reductions in fitness during winter. However, groundwater inputs can moderate water temperature and may reduce winter severity. Additionally, seasonal reductions in prey availability may contribute to decreased growth and survival, although few studies have examined food webs supporting salmonids under winter conditions. This study employed diet, stable isotope, and mark-recapture techniques to examine winter (November through March) feeding, growth, and condition of brown trout Salmo trutta in a groundwater-dominated stream (Badger Creek, Minnesota, USA). Growth was greater for fish ≤ 150 mm (mean = 4.1 mg g-1 day-1) than for those 151-276 mm (mean = 1.0 mg g-1 day-1) during the winter season. Overall condition from early winter to late winter did not vary for fish ≤150 mm (mean relative weight (Wr) = 89.5) and increased for those 151-276 mm (mean Wr = 85.8 early and 89.4 late). Although composition varied both temporally and by individual, brown trout diets were dominated by aquatic invertebrates, primarily Amphipods, Dipterans, and Trichopterans. Stable isotope analysis supported the observations of the dominant prey taxa in stomach contents and indicated the winter food web was supported by a combination of allochthonous inputs and aquatic macrophytes. Brown trout in Badger Creek likely benefited from the thermal regime and increased prey abundance present in this groundwater-dominated stream during winter.

Original languageEnglish (US)
Pages (from-to)187-200
Number of pages14
JournalJournal of Freshwater Ecology
Volume29
Issue number2
DOIs
StatePublished - Apr 3 2014

Keywords

  • brown trout
  • condition
  • growth
  • stable isotopes
  • winter diet

Fingerprint Dive into the research topics of 'Winter feeding, growth and condition of brown trout Salmo trutta in a groundwater-dominated stream'. Together they form a unique fingerprint.

Cite this