Surface environment modification in Atlantic salmon sea-cages: effects on amoebic gill disease, salmon lice, growth and welfare
Surface environment modification is a potential parasite control strategy in Atlantic salmon sea-cage farming. For instance, a temporary low salinity surface layer in commercial-scale snorkel sea-cages has coincided with reduced amoebic gill disease (AGD) levels after an outbreak. We tested if a per...
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ftunivtasmania:oai:eprints.utas.edu.au:41775 2023-05-15T15:31:50+02:00 Surface environment modification in Atlantic salmon sea-cages: effects on amoebic gill disease, salmon lice, growth and welfare Wright, DW Geitung, L Karlsbakk, E Stien, LH Dempster, T Oldham, T Nola, V Oppedal, F 2018 https://eprints.utas.edu.au/41775/ unknown Inter-Research Wright, DW, Geitung, L, Karlsbakk, E, Stien, LH, Dempster, T, Oldham, T, Nola, V and Oppedal, F 2018 , 'Surface environment modification in Atlantic salmon sea-cages: effects on amoebic gill disease, salmon lice, growth and welfare' , Aquaculture Environment Interactions, vol. 10 , pp. 255-265 , doi:10.3354/AEI00269 <http://dx.doi.org/10.3354/AEI00269>. aquaculture cage environment Salmo salar Lepeophtheirus salmonis Paramoeba perurans parasite control Article PeerReviewed 2018 ftunivtasmania https://doi.org/10.3354/AEI00269 2022-01-31T23:18:32Z Surface environment modification is a potential parasite control strategy in Atlantic salmon sea-cage farming. For instance, a temporary low salinity surface layer in commercial-scale snorkel sea-cages has coincided with reduced amoebic gill disease (AGD) levels after an outbreak. We tested if a permanent freshwater (FW) surface layer in snorkel sea-cages would lower AGD and salmon lice levels of stock relative to snorkel cages with seawater (SW) only and standard production cages with no snorkels. Triplicate cages of each type with 2000 post-smolts were monitored in autumn to winter for 8 wk and sampled 4 times. Lower proportions of individuals with elevated AGD-related gill scores were registered in SW and FW snorkel cages compared to standard cages; however, these proportions did not differ between SW and FW snorkel cages. Individuals positive for AGD-causing Paramoeba perurans were reduced by 65% in FW snorkel relative to standard cages, but values were similar between SW snorkel cages and other types. While total lice burdens were reduced by 38% in SW snorkel compared to standard cages, they were unchanged between FW snorkel and other cage types. Fish welfare and growth were unaffected by cage type. Surface activity was detected in all cages; however, more surface jumps were recorded in standard than snorkel cages. Overall, fish in FW snorkel cages appeared to reside too little in freshwater to consistently reduce AGD levels and salmon lice compared to SW snorkel cages. Further work should test behavioural and environmental manipulations aimed at increasing freshwater or low salinity surface layer use. Article in Journal/Newspaper Atlantic salmon Salmo salar University of Tasmania: UTas ePrints Aquaculture Environment Interactions 10 255 265 |
institution |
Open Polar |
collection |
University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
unknown |
topic |
aquaculture cage environment Salmo salar Lepeophtheirus salmonis Paramoeba perurans parasite control |
spellingShingle |
aquaculture cage environment Salmo salar Lepeophtheirus salmonis Paramoeba perurans parasite control Wright, DW Geitung, L Karlsbakk, E Stien, LH Dempster, T Oldham, T Nola, V Oppedal, F Surface environment modification in Atlantic salmon sea-cages: effects on amoebic gill disease, salmon lice, growth and welfare |
topic_facet |
aquaculture cage environment Salmo salar Lepeophtheirus salmonis Paramoeba perurans parasite control |
description |
Surface environment modification is a potential parasite control strategy in Atlantic salmon sea-cage farming. For instance, a temporary low salinity surface layer in commercial-scale snorkel sea-cages has coincided with reduced amoebic gill disease (AGD) levels after an outbreak. We tested if a permanent freshwater (FW) surface layer in snorkel sea-cages would lower AGD and salmon lice levels of stock relative to snorkel cages with seawater (SW) only and standard production cages with no snorkels. Triplicate cages of each type with 2000 post-smolts were monitored in autumn to winter for 8 wk and sampled 4 times. Lower proportions of individuals with elevated AGD-related gill scores were registered in SW and FW snorkel cages compared to standard cages; however, these proportions did not differ between SW and FW snorkel cages. Individuals positive for AGD-causing Paramoeba perurans were reduced by 65% in FW snorkel relative to standard cages, but values were similar between SW snorkel cages and other types. While total lice burdens were reduced by 38% in SW snorkel compared to standard cages, they were unchanged between FW snorkel and other cage types. Fish welfare and growth were unaffected by cage type. Surface activity was detected in all cages; however, more surface jumps were recorded in standard than snorkel cages. Overall, fish in FW snorkel cages appeared to reside too little in freshwater to consistently reduce AGD levels and salmon lice compared to SW snorkel cages. Further work should test behavioural and environmental manipulations aimed at increasing freshwater or low salinity surface layer use. |
format |
Article in Journal/Newspaper |
author |
Wright, DW Geitung, L Karlsbakk, E Stien, LH Dempster, T Oldham, T Nola, V Oppedal, F |
author_facet |
Wright, DW Geitung, L Karlsbakk, E Stien, LH Dempster, T Oldham, T Nola, V Oppedal, F |
author_sort |
Wright, DW |
title |
Surface environment modification in Atlantic salmon sea-cages: effects on amoebic gill disease, salmon lice, growth and welfare |
title_short |
Surface environment modification in Atlantic salmon sea-cages: effects on amoebic gill disease, salmon lice, growth and welfare |
title_full |
Surface environment modification in Atlantic salmon sea-cages: effects on amoebic gill disease, salmon lice, growth and welfare |
title_fullStr |
Surface environment modification in Atlantic salmon sea-cages: effects on amoebic gill disease, salmon lice, growth and welfare |
title_full_unstemmed |
Surface environment modification in Atlantic salmon sea-cages: effects on amoebic gill disease, salmon lice, growth and welfare |
title_sort |
surface environment modification in atlantic salmon sea-cages: effects on amoebic gill disease, salmon lice, growth and welfare |
publisher |
Inter-Research |
publishDate |
2018 |
url |
https://eprints.utas.edu.au/41775/ |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_relation |
Wright, DW, Geitung, L, Karlsbakk, E, Stien, LH, Dempster, T, Oldham, T, Nola, V and Oppedal, F 2018 , 'Surface environment modification in Atlantic salmon sea-cages: effects on amoebic gill disease, salmon lice, growth and welfare' , Aquaculture Environment Interactions, vol. 10 , pp. 255-265 , doi:10.3354/AEI00269 <http://dx.doi.org/10.3354/AEI00269>. |
op_doi |
https://doi.org/10.3354/AEI00269 |
container_title |
Aquaculture Environment Interactions |
container_volume |
10 |
container_start_page |
255 |
op_container_end_page |
265 |
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1766362346298540032 |