Energetic Consequences of Stranding of Juvenile Atlantic Salmon (Salmo salar L.)

Michael Puffer,Svein Jakob Saltveit,Sigurd Einum,Ole Kristian Berg,Torbjørn Forseth

doi:10.4236/jwarp.2017.92012

Abstract

An effect of hydropower and hydropeaking regulation in rivers is stranding of fish. Those fishes that survive stranding may experience stranding as a stressful situation. In four experimental stranding experiments (each with 6 individuals in 10 control and 10 treatment replicates), the energetic consequences of two forms of stranding (i.e. trapping and beaching) of juvenile Atlantic salmon (Salmo salar) were investigated in summer and winter. Restricted food access in the experimental channels ensured that effects of hydropeaking could be revealed. Mean fish length ranged between 60 mm and 110 mm among experiments. Both during the winter and summer experiments fish did not grow in length, neither in the control nor in the treatment channels and fish lost body mass as well as body fat in all experiments (body fat in summer trapping experiment not determined). The four experiments revealed similar results: stranding did not affect growth or energy content. Despite the severity of the stranding and the resulting mortality, which was especially high during summer, no stranding related effects on fish performance could be detected.

Highlights

Climate change is a driver for increased demand of renewable energy, i.e. hydropower, wind and solar energy [1] [2] [3] [4]
In the winter beaching experiment, no fish died during the beaching episodes, and by the end of the experimental period, only one fish had died in a treatment channel
Seven more fish died in the treatment channels, whereas five fish died in the control channels

Summary

Introduction

Climate change is a driver for increased demand of renewable energy, i.e. hydropower, wind and solar energy [1] [2] [3] [4]. Riverine aquatic organisms are adapted to natural flow fluctuations, but the amplitude and high rate of flow changes during hydropeaking have a suite of effects on river ecosystems [11] [12] [13]. It may alter the riverine habitat dramatically, leading to dewatered riverbeds strongly affecting riverine organisms through stranding. When water levels drop rapidly during hydropeaking episodes, juvenile salmonids may be trapped in bankside gravel, in ponds or within the substrate, where inflow of groundwater or interstitial water is important for survival (reviewed by [21]). On the other hand, such experiences may be stressful [22] or cause damage that may affect their longterm performance and survival

Methods

Results

Discussion

Conclusion