A mechanistic assessment of seasonal microhabitat selection by drift-feeding rainbow trout Oncorhynchus mykiss in a Southwestern headwater stream
Authored by Bradley W Kalb, Brock M Huntsman, Colleen A Caldwell, Michael A Bozek
Date Published: 2018
DOI: 10.1007/s10641-017-0696-9
Sponsors:
United States Geological Survey (USGS)
United States Fish and Wildlife Service
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
The positioning of fishes within a riverscape is dependent on the
proximity of complementary habitats. In this study, foraging and
non-foraging habitat were quantified monthly over an entire year for a
rainbow trout (Oncorhynchus mykiss) population in an isolated, headwater
stream in southcentral New Mexico. The stream follows a seasonal thermal
and hydrologic pattern typical for a Southwestern stream and was deemed
suitable for re-introduction of the native and close relative, Rio
Grande cutthroat trout (O. clarkii virginalis). However, uncertainty
associated with limited habitat needed to be resolved if repatriation of
the native fish was to be successful. Habitat was evaluated using
resource selection functions with a mechanistic drift-foraging model to
explain trout distributions. Macroinvertebrate drift was strongly
season- and temperature-dependent (lower in winter and spring, higher in
summer and fall). Models identified stream depth as the most limiting
factor for habitat selection across seasons and size-classes.
Additionally, positions closer to cover were selected during the winter
by smaller size-classes (0, 1, 2), while net energy intake was important
during the spring for most size-classes (0, 1, 2, 3). Drift-foraging
models identified that 81\% of observed trout selected positions that
could meet maintenance levels throughout the year. Moreover, 40\% of
selected habitats could sustain maximum growth. Stream positions
occupied by rainbow trout were more energetically profitable than random
sites regardless of season or size-class. Larger size-classes (3, 4+)
were energetically more limited throughout the year than were smaller
size-classes. This research suggests that habitat in the form of deep
pools is of paramount importance for rainbow trout or native cutthroat
trout.
Tags
Individual-based model
Atlantic salmon
Climate-change
Body-size
Brown trout
Habitat-selection
Brook trout
Cutthroat trout
Water
temperature
Position choice
Energetics
Salmonid
Microhabitat selection
Drift-foraging models