Estimation of salmonid habitat growth potential through measurements of invertebrate food abundance and temperature

Authored by Nicholas Weber, Nicolaas Bouwes, Chris E Jordan

Date Published: 2014

DOI: 10.1139/cjfas-2013-0390

Sponsors: United States National Oceanic and Atmospheric Administration (NOAA)

Platforms: No platforms listed

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

Criteria used to characterize lotic salmonid habitat suitability are often based on correlations between physical habitat characteristics and salmonid abundance. Focusing on physical habitat features ignores other habitat components, such as an adequate food supply, that limit the amount of energy available for growth and survival. We tested the degree that food availability and temperature influence lotic salmonid consumption and growth rates and outline an approach for assessing habitat quality based on measurements of these features. We collected benthic and drifting invertebrate abundances, stream temperatures, and juvenile steelhead - rainbow trout (Onchorhynchus mykiss gairdneri) summer growth rates among nine stream segments in central Oregon. Stream temperatures and growth rates were used in bioenergetics model simulations to estimate O. mykiss consumption rates. The variation in O. mykiss consumption rates was explained by measurements of total drift biomass along a type II predator response curve (R-2 = 0.71). This simplified foraging relationship between food abundance and consumption is then used to estimate the consumption component of the bioenergetics model to allow estimation of salmonid growth potential. Validation of the growth potential model produced reasonably accurate estimates of fish growth rates at reaches within the study area and precise but biased estimates in novel systems. While additional reach-level habitat information may be required to make the model more generalizable, the assessment of invertebrate food availability offers a simple yet powerful approach for describing the growth potential of stream habitat.
Tags
Individual-based model Brown trout Cutthroat trout Stream salmonids Trout oncorhynchus-mykiss Drift-feeding salmonids Juvenile rainbow-trout Coho salmon Terrestrial invertebrates Territory size