Rainbow smelt spawning population and habitat characteristics in a Missouri River reservoir

Journal of Freshwater Ecology

Mark J. Fincel¹  Brian D. S. Graeb²  Nicholas B. Kludt³ 

[1] Game, Fish and Parks, South Dakota Department of Game, Ft. Pierre, SD, US;Natural Resource Management, South Dakota State University, Brookings, SD, US;Natural Resources, Minnesota Department of Natural Resources, Detroit Lakes, MN, US;

关键词: Lake Oahe;    ydroacoustics;    Osmerus mordax;    spawning habitat;    South Dakota;   

DOI  :  10.1080/02705060.2021.1967209

来源: Taylor & Francis

【 摘 要 】

Rainbow Smelt Osmerus mordax are the primary coldwater forage species in Lake Oahe, South Dakota, yet most aspects of their life history remain unknown. As Missouri River reservoirs present a novel habitat compared to elsewhere in the Rainbow Smelt’s range, we investigated their spawning site use relative to available physical and thermal habitat from spring 2016 − 2018 using a mobile horizontal-beaming hydroacoustic survey. We mapped spawning habitat using side-scanning sonar to establish relationships with site bathymetry and thermal spawning conditions. From our site mapping, we determined the depth, slope, bottom hardness, and ruggedness of individual sites. We used a PCA to condense our physical habitat metrics, with PC1 representing 77% of cumulative variance. Peak abundance was linked to a physical habitat gradient, representing [steep slope, deep, soft bottom] to [low slope, shallow, hard bottom]. Peak Rainbow Smelt spawning aggregations were observed at 6.8 ± 1.7 °C (Mean ± StDev). An information-theoretic regression analysis revealed an interactive effect of temperature and habitat, whereby shallower, warmer sites typically had a lower peak abundance. These results represent the first step toward understanding habitat use characteristics of spawning Rainbow Smelt in reservoir systems.

【 授权许可】

CC BY