Effects of avoidance behavior on downstream fish passage through areas of accelerating flow when light and dark
Effects of avoidance behavior on downstream fish passage through areas of accelerating flow when light and dark
To mitigate negative impacts of delayed migration it is necessary to understand the causes of avoidance exhibited by animals at behavioural barriers. For downstream migrating juvenile salmon, avoidance of velocity gradients at anthropogenic structures may compromise fitness. Building on previous experimental investigations on salmonid response to velocity gradients, this study aimed to quantify impacts of behaviour on subsequent passage in the presence and absence of visual cues. In an experimental flume, downstream moving juvenile Chinook salmon, Oncorhynchus tshawytscha, encountered either a high or a low velocity gradient created by an orifice weir, under light (95 lx) or dark (infrared illumination only) conditions. The majority of fish exhibited an observable response on encountering accelerating velocity, with avoidance behaviour elevated when light (45%) in comparison to when dark (12%). More time was spent facing the flow when the velocity gradient was high. Fish that exhibited avoidance were delayed by approximately eight-fold, travelled 3.5 times further, and experienced a higher mean cumulative velocity gradient across the body length (spatial velocity gradient) prior to successful downstream passage. This study highlights the impact of variation in behaviour on fish passage, and the potential for combined multimodal signals (in this instance visual and mechanosensory) to be used to repel fish, for example from hazardous areas such as turbine intakes. Conversely, by limiting information available, undesirable delay, for example at entrances to downstream fish bypasses, may be reduced
environmental stimuli, habitat fragmentation, migration, salmon, smolt, velocity gradient
101-109
Vowles, Andrew
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Anderson, James J.
5851c215-4e63-4566-9107-8747fc05bf56
Gessel, Mike G.
baf21559-6570-49c4-b7b4-fd5289939b14
Williams, John G.
8af57e50-bcaf-4da4-ba08-42782858e0df
Kemp, P.S.
9e33fba6-cccf-4eb5-965b-b70e72b11cd7
2014
Vowles, Andrew
c35c3a75-2199-4665-8340-e8ee7abc25f4
Anderson, James J.
5851c215-4e63-4566-9107-8747fc05bf56
Gessel, Mike G.
baf21559-6570-49c4-b7b4-fd5289939b14
Williams, John G.
8af57e50-bcaf-4da4-ba08-42782858e0df
Kemp, P.S.
9e33fba6-cccf-4eb5-965b-b70e72b11cd7
Vowles, Andrew, Anderson, James J., Gessel, Mike G., Williams, John G. and Kemp, P.S.
(2014)
Effects of avoidance behavior on downstream fish passage through areas of accelerating flow when light and dark.
Animal Behaviour, 92, .
(doi:10.1016/j.anbehav.2014.03.006).
Abstract
To mitigate negative impacts of delayed migration it is necessary to understand the causes of avoidance exhibited by animals at behavioural barriers. For downstream migrating juvenile salmon, avoidance of velocity gradients at anthropogenic structures may compromise fitness. Building on previous experimental investigations on salmonid response to velocity gradients, this study aimed to quantify impacts of behaviour on subsequent passage in the presence and absence of visual cues. In an experimental flume, downstream moving juvenile Chinook salmon, Oncorhynchus tshawytscha, encountered either a high or a low velocity gradient created by an orifice weir, under light (95 lx) or dark (infrared illumination only) conditions. The majority of fish exhibited an observable response on encountering accelerating velocity, with avoidance behaviour elevated when light (45%) in comparison to when dark (12%). More time was spent facing the flow when the velocity gradient was high. Fish that exhibited avoidance were delayed by approximately eight-fold, travelled 3.5 times further, and experienced a higher mean cumulative velocity gradient across the body length (spatial velocity gradient) prior to successful downstream passage. This study highlights the impact of variation in behaviour on fish passage, and the potential for combined multimodal signals (in this instance visual and mechanosensory) to be used to repel fish, for example from hazardous areas such as turbine intakes. Conversely, by limiting information available, undesirable delay, for example at entrances to downstream fish bypasses, may be reduced
Text
Vowles et al 2014a.pdf
- Author's Original
More information
Accepted/In Press date: 11 February 2014
e-pub ahead of print date: 25 April 2014
Published date: 2014
Keywords:
environmental stimuli, habitat fragmentation, migration, salmon, smolt, velocity gradient
Organisations:
Water & Environmental Engineering Group
Identifiers
Local EPrints ID: 364460
URI: http://eprints.soton.ac.uk/id/eprint/364460
ISSN: 0003-3472
PURE UUID: af427341-2e8c-4ac6-b220-6773714644cd
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Date deposited: 29 Apr 2014 10:25
Last modified: 15 Mar 2024 03:34
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Author:
James J. Anderson
Author:
Mike G. Gessel
Author:
John G. Williams
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