Modelling the effects of stranding on the Atlantic salmon population in the Dale River, Norway

Authored by Richard D Hedger, Line E Sundt-Hansen, Ola Ugedal, Julian F Sauterleute, Christoph Hauer, Ulrich Pulg, Helge Skoglund, Tor Haakon Bakken

Date Published: 2016

DOI: 10.1016/j.scitotenv.2016.08.080

Sponsors: Norwegian Research Council (NRF) Centre for Environmental Design of Renewable Energy (CEDREN)

Platforms: No platforms listed

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

Rapid dewatering in rivers as a consequence of hydropower operations may cause stranding of juvenile fish and have a negative impact on fish populations. We implemented stranding into an Atlantic salmon population model in order to evaluate long-term effects on the population in the Dale River, Western Norway. Furthermore, we assessed the sensitivity of the stranding model to dewatered area in comparison-to biological parameters, and compared different methods for calculating wetted area, the main abiotic input parameter to the population model. Five scenarios were simulated dependent on fish life-stage, season and light level. Our simulation results showed largest negative effect on the population abundance for hydropeaking during winter daylight Salmon smolt production had highest sensitivity to the stranding mortality of older juvenile fish, Suggesting that stranding of fish at these life-stages is likely to have greater population impacts than that of earlier life-stages. Downstream retention effects on the ramping velocity were found to be negligible in the stranding model, but are suggested to be important in the context of mitigation measure design. (C) 2016 Elsevier B.V. All rights reserved.

Tags

morphology Impacts Salar l. Winter Density-dependent mortality Juvenile brown trout Rapid flow decreases Stream fishes Hydropeaking Trutta