Using ‘trap and transport’ to facilitate seaward migration of landlocked European eel (Anguilla anguilla) from lakes and reservoirs
Using ‘trap and transport’ to facilitate seaward migration of landlocked European eel (Anguilla anguilla) from lakes and reservoirs
‘Trap and transport’ (T&T) is employed to facilitate the seaward migration of European eel (Anguilla anguilla) past obstacles such as hydropower facilities. Hence, previous studies assessing its efficacy have focussed on disrupted fluvial systems. The transferability of findings from lotic to lentic systems is uncertain because many of the environmental cues that trigger eel migration in rivers are lacking from reservoirs and lakes, particularly those with limited flow connection to the surrounding catchment. We used acoustic telemetry to compare the migration behaviour of T&T adult A. anguilla which were fyke netted and transported from two disconnected reservoirs (n = 80) to a control group of resident river eel (n = 30) during their migration through the lower River Stour, UK, to the North Sea. Migration patterns and behaviour were broadly similar between the reservoir T&T eel and river eel with 86 and 90% of each group successfully reaching the sea, respectively. Reservoir eel were larger and at a more advanced stage of migratory readiness (silvering) and commenced migration sooner after release than the river eel, but they descended the catchment at a slower rate. Behaviour in the estuary was highly variable between individuals with residence times ranging from 5 h to 83 days (median = 1.4 days) across all groups. Only one individual failed to migrate through the estuary and most (75%) reached the sea within five days of entering the estuary. Findings indicate that T&T of adult eel from reservoirs represents a feasible method to allow landlocked individuals to migrate and potentially contribute to the spawning stock, either now or in the future. Results also highlighted the high capture effort that may be required to implement an effective T&T programme. Gaining a thorough understanding of eel abundance and population structure in the source waterbody is desirable before implementation.
Acoustic telemetry; trap and haul; fish migration; fyke netting; hydropower; pumping station
Piper, Adam T
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Rosewarne, Paula
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Wright, Rosalind
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Kemp, Paul
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August 2020
Piper, Adam T
2c816a29-68a2-4267-8283-fef27c2e75f3
Rosewarne, Paula
91964883-ac1a-43c2-9179-cee1816e12b6
Wright, Rosalind
e948f571-799b-40af-8d4d-8eedbec7fb88
Kemp, Paul
9e33fba6-cccf-4eb5-965b-b70e72b11cd7
Piper, Adam T, Rosewarne, Paula, Wright, Rosalind and Kemp, Paul
(2020)
Using ‘trap and transport’ to facilitate seaward migration of landlocked European eel (Anguilla anguilla) from lakes and reservoirs.
Fisheries Research, 228, [105567].
(doi:10.1016/j.fishres.2020.105567).
Abstract
‘Trap and transport’ (T&T) is employed to facilitate the seaward migration of European eel (Anguilla anguilla) past obstacles such as hydropower facilities. Hence, previous studies assessing its efficacy have focussed on disrupted fluvial systems. The transferability of findings from lotic to lentic systems is uncertain because many of the environmental cues that trigger eel migration in rivers are lacking from reservoirs and lakes, particularly those with limited flow connection to the surrounding catchment. We used acoustic telemetry to compare the migration behaviour of T&T adult A. anguilla which were fyke netted and transported from two disconnected reservoirs (n = 80) to a control group of resident river eel (n = 30) during their migration through the lower River Stour, UK, to the North Sea. Migration patterns and behaviour were broadly similar between the reservoir T&T eel and river eel with 86 and 90% of each group successfully reaching the sea, respectively. Reservoir eel were larger and at a more advanced stage of migratory readiness (silvering) and commenced migration sooner after release than the river eel, but they descended the catchment at a slower rate. Behaviour in the estuary was highly variable between individuals with residence times ranging from 5 h to 83 days (median = 1.4 days) across all groups. Only one individual failed to migrate through the estuary and most (75%) reached the sea within five days of entering the estuary. Findings indicate that T&T of adult eel from reservoirs represents a feasible method to allow landlocked individuals to migrate and potentially contribute to the spawning stock, either now or in the future. Results also highlighted the high capture effort that may be required to implement an effective T&T programme. Gaining a thorough understanding of eel abundance and population structure in the source waterbody is desirable before implementation.
Text
Using ‘trap and transport’
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More information
Accepted/In Press date: 21 March 2020
e-pub ahead of print date: 4 April 2020
Published date: August 2020
Additional Information:
Funding Information:
This study was joint funded by the Environment Agency , the University of Southampton , Anglian Water and Northumbrian Water . The authors would like to thank staff at Alton Water, Hanningfield Reservoir and the Environment Agency for assistance in the field.
Publisher Copyright:
© 2020 The Author(s)
Keywords:
Acoustic telemetry; trap and haul; fish migration; fyke netting; hydropower; pumping station
Identifiers
Local EPrints ID: 439207
URI: http://eprints.soton.ac.uk/id/eprint/439207
ISSN: 0165-7836
PURE UUID: cdd10e58-2f47-4f9b-8899-2ca0b6c458ee
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Date deposited: 07 Apr 2020 16:30
Last modified: 17 Mar 2024 03:00
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Author:
Adam T Piper
Author:
Paula Rosewarne
Author:
Rosalind Wright
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