Supplementary material from "Leaky barriers: leaky enough for fish to pass?"

Perceived as environmental-friendly hydraulic structures, leaky barriers used for natural flood management are introduced into rivers, potentially creating migration barriers for fish. Using sustainable, local materials to construct wooden barriers across river channels in upper catchments, these ba...

Full description

Bibliographic Details
Main Authors: Müller, Stephanie, Wilson, Catherine A. M. E., Ouro, Pablo, Cable, Joanne
Format: Article in Journal/Newspaper
Language:unknown
Published: The Royal Society 2021
Subjects:
Online Access:https://dx.doi.org/10.6084/m9.figshare.c.5310099.v2
https://rs.figshare.com/collections/Supplementary_material_from_Leaky_barriers_leaky_enough_for_fish_to_pass_/5310099/2
Description
Summary:Perceived as environmental-friendly hydraulic structures, leaky barriers used for natural flood management are introduced into rivers, potentially creating migration barriers for fish. Using sustainable, local materials to construct wooden barriers across river channels in upper catchments, these barriers aim to slow down the flow, reduce flood peaks and attenuate the flow reaching downstream communities. Yet little is known about their impact on hydrodynamics and fish passage. Here, we examined two model barrier designs under 100% and 80% bankfull flow conditions in an open channel flume. These barriers included a porous and a non-porous design, with the latter emulating the natural accumulation of brush, sediment and leaf material between logs over time. Flow visualization and velocity measurements recorded with acoustic Doppler velocimetry characterized the flow field upstream and downstream of the barriers. Our fish behavioural studies revealed that juvenile salmon ( Salmo salar ) movement between downstream and upstream sections of the flume was inhibited by barrier design rather than discharge, influencing upstream fish passage and their spatial preference, indicating the importance of barrier design criteria to facilitate fish movement.