Caught in the trap: over half of the farmed Atlantic salmon removed from a wild spawning population in the period 2014-2018 were mature

Whilst aquaculture continues its global expansion, containment of fish in sea cages remains a persistent environmental challenge. Within Atlantic salmon Salmo salar farming, widespread escapes over several decades have left a legacy of ecological and genetic impacts on wild populations. Quantifying...

Full description

Bibliographic Details
Main Authors: AS Madhun, A Harvey, Ø Skaala, V Wennevik, S Knutar, MF Solberg, M Quintela, PT Fjeldheim, S Meier, KA Glover
Format: Article
Language:English
Published: Inter-Research 2023-08-01
Series:Aquaculture Environment Interactions
Online Access:https://www.int-res.com/abstracts/aei/v15/p271-285/
_version_ 1827793306510163968
author AS Madhun
A Harvey
Ø Skaala
V Wennevik
S Knutar
MF Solberg
M Quintela
PT Fjeldheim
S Meier
KA Glover
author_facet AS Madhun
A Harvey
Ø Skaala
V Wennevik
S Knutar
MF Solberg
M Quintela
PT Fjeldheim
S Meier
KA Glover
author_sort AS Madhun
collection DOAJ
description Whilst aquaculture continues its global expansion, containment of fish in sea cages remains a persistent environmental challenge. Within Atlantic salmon Salmo salar farming, widespread escapes over several decades have left a legacy of ecological and genetic impacts on wild populations. Quantifying the characteristics of escapees, and how they vary in time and space, is important to understand how environmental impacts will vary and how mitigation strategies need to be tuned. Using a fish trap located in the River Etne on the west coast of Norway, we created an ecological and genetic profile for 616 escapees entering the river. The most important findings of the present study were (1) the annual number of escapees entering the trap declined in the period 2014-2018; (2) more than half of the escapees entering the river were mature; (3) the vast majority of escapees entering the river were categorised as recent escapees; (4) nearly all (96%) of the early escapees were mature upon entry to the river, while just over half (55%) of the recent escapees were mature; and (5) the escapees originated from multiple sources every year. We conclude that without the fish trap, this population would have been at risk of exposure to further spawning and introgression of domesticated salmon. Furthermore, the current findings of maturation status and escape history highlight the fact that mitigation efforts to reduce escape of smolts, post-smolts and larger fish all need continued attention from the management authorities and aquaculture industry.
first_indexed 2024-03-11T18:15:37Z
format Article
id doaj.art-daf780a41310469889b635297b022345
institution Directory Open Access Journal
issn 1869-215X
1869-7534
language English
last_indexed 2024-03-11T18:15:37Z
publishDate 2023-08-01
publisher Inter-Research
record_format Article
series Aquaculture Environment Interactions
spelling doaj.art-daf780a41310469889b635297b0223452023-10-16T08:17:40ZengInter-ResearchAquaculture Environment Interactions1869-215X1869-75342023-08-011527128510.3354/aei00465Caught in the trap: over half of the farmed Atlantic salmon removed from a wild spawning population in the period 2014-2018 were matureAS Madhun0A Harvey1Ø Skaala2V Wennevik3S Knutar4MF Solberg5M Quintela6PT Fjeldheim7S Meier8KA Glover9Institute of Marine Research, Nordnesgaten 50, 5005 Bergen, NorwayInstitute of Marine Research, Nordnesgaten 50, 5005 Bergen, NorwayInstitute of Marine Research, Nordnesgaten 50, 5005 Bergen, NorwayInstitute of Marine Research, Nordnesgaten 50, 5005 Bergen, NorwayInstitute of Marine Research, Nordnesgaten 50, 5005 Bergen, NorwayInstitute of Marine Research, Nordnesgaten 50, 5005 Bergen, NorwayInstitute of Marine Research, Nordnesgaten 50, 5005 Bergen, NorwayInstitute of Marine Research, Nordnesgaten 50, 5005 Bergen, NorwayInstitute of Marine Research, Nordnesgaten 50, 5005 Bergen, NorwayInstitute of Marine Research, Nordnesgaten 50, 5005 Bergen, NorwayWhilst aquaculture continues its global expansion, containment of fish in sea cages remains a persistent environmental challenge. Within Atlantic salmon Salmo salar farming, widespread escapes over several decades have left a legacy of ecological and genetic impacts on wild populations. Quantifying the characteristics of escapees, and how they vary in time and space, is important to understand how environmental impacts will vary and how mitigation strategies need to be tuned. Using a fish trap located in the River Etne on the west coast of Norway, we created an ecological and genetic profile for 616 escapees entering the river. The most important findings of the present study were (1) the annual number of escapees entering the trap declined in the period 2014-2018; (2) more than half of the escapees entering the river were mature; (3) the vast majority of escapees entering the river were categorised as recent escapees; (4) nearly all (96%) of the early escapees were mature upon entry to the river, while just over half (55%) of the recent escapees were mature; and (5) the escapees originated from multiple sources every year. We conclude that without the fish trap, this population would have been at risk of exposure to further spawning and introgression of domesticated salmon. Furthermore, the current findings of maturation status and escape history highlight the fact that mitigation efforts to reduce escape of smolts, post-smolts and larger fish all need continued attention from the management authorities and aquaculture industry.https://www.int-res.com/abstracts/aei/v15/p271-285/
spellingShingle AS Madhun
A Harvey
Ø Skaala
V Wennevik
S Knutar
MF Solberg
M Quintela
PT Fjeldheim
S Meier
KA Glover
Caught in the trap: over half of the farmed Atlantic salmon removed from a wild spawning population in the period 2014-2018 were mature
Aquaculture Environment Interactions
title Caught in the trap: over half of the farmed Atlantic salmon removed from a wild spawning population in the period 2014-2018 were mature
title_full Caught in the trap: over half of the farmed Atlantic salmon removed from a wild spawning population in the period 2014-2018 were mature
title_fullStr Caught in the trap: over half of the farmed Atlantic salmon removed from a wild spawning population in the period 2014-2018 were mature
title_full_unstemmed Caught in the trap: over half of the farmed Atlantic salmon removed from a wild spawning population in the period 2014-2018 were mature
title_short Caught in the trap: over half of the farmed Atlantic salmon removed from a wild spawning population in the period 2014-2018 were mature
title_sort caught in the trap over half of the farmed atlantic salmon removed from a wild spawning population in the period 2014 2018 were mature
url https://www.int-res.com/abstracts/aei/v15/p271-285/
work_keys_str_mv AT asmadhun caughtinthetrapoverhalfofthefarmedatlanticsalmonremovedfromawildspawningpopulationintheperiod20142018weremature
AT aharvey caughtinthetrapoverhalfofthefarmedatlanticsalmonremovedfromawildspawningpopulationintheperiod20142018weremature
AT øskaala caughtinthetrapoverhalfofthefarmedatlanticsalmonremovedfromawildspawningpopulationintheperiod20142018weremature
AT vwennevik caughtinthetrapoverhalfofthefarmedatlanticsalmonremovedfromawildspawningpopulationintheperiod20142018weremature
AT sknutar caughtinthetrapoverhalfofthefarmedatlanticsalmonremovedfromawildspawningpopulationintheperiod20142018weremature
AT mfsolberg caughtinthetrapoverhalfofthefarmedatlanticsalmonremovedfromawildspawningpopulationintheperiod20142018weremature
AT mquintela caughtinthetrapoverhalfofthefarmedatlanticsalmonremovedfromawildspawningpopulationintheperiod20142018weremature
AT ptfjeldheim caughtinthetrapoverhalfofthefarmedatlanticsalmonremovedfromawildspawningpopulationintheperiod20142018weremature
AT smeier caughtinthetrapoverhalfofthefarmedatlanticsalmonremovedfromawildspawningpopulationintheperiod20142018weremature
AT kaglover caughtinthetrapoverhalfofthefarmedatlanticsalmonremovedfromawildspawningpopulationintheperiod20142018weremature