Spawning habitat suitability for coastal cutthroat trout: Microhabitat and mesohabitat

Autor: Steven N. Boessow, Kiza K. Gates, Hal A. Beecher
Rok vydání: 2020
Předmět:
Zdroj: Aquatic Conservation: Marine and Freshwater Ecosystems. 31:480-493
ISSN: 1099-0755
1052-7613
DOI: 10.1002/aqc.3431
Popis: The conservation of aquatic species with complex life histories requires the protection of habitat for each life stage. Coastal cutthroat trout (Oncorhynchus clarkii clarkii) exhibit both mobile and sessile stages and are of conservation concern in north‐western North America. Models that predict how habitat changes with flow can inform water management for the species but rely on habitat descriptors that change with flow and are not suited to sessile life stages. Spawning and incubation habitat availability and use for coastal cutthroat trout were assessed in mesohabitats and microhabitats. Primary channel units were tallied, dimensions were measured, redds were counted, and redd locations within channel units were measured. Primary channel units were subdivided based on relative residual depth (RRD, bed elevation in relation to maximum pool depth) and hydraulic control (HC, the lowest point on the highest ridge across the riffle that controls the water surface elevation in the upstream pool). Habitat suitability was calculated for depth (D), velocity (V), Froude number (Fr), substrate (S), RRD, and channel units. Redds in riffles and pools were close to hydraulic controls; suitability decreased upstream in pools and downstream in riffles. Maximum suitability values were: 21–24 cm for D, 0.05–0.10 for RRD, 61–64 cm s⁻¹ for V, >0.80 for Fr, and 1.3 to
Databáze: OpenAIRE
Externí odkaz: