Effects of cnidarian biofouling on salmon gill health and development of amoebic gill disease
This study examines the potential implications of biofouling management on the development of an infectious disease in Norwegian farmed salmon. The hydroid Ectopleura larynx frequently colonises cage nets at high densities (thousands of colonies per m2) and is released into the water during regular...
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Online Access: | http://hdl.handle.net/11250/2505077 https://doi.org/10.1371/journal.pone.0199842 |
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ftsintef:oai:sintef.brage.unit.no:11250/2505077 2023-05-15T15:33:05+02:00 Effects of cnidarian biofouling on salmon gill health and development of amoebic gill disease Bloecher, Nina Powell, Mark Hytterød, Sigurd Gjessing, Mona Cecilie Wiik-Nielsen, Jannicke Mohammad, Saima Hansen, Haakon Floerl, Oliver Gjevre, Anne Gerd 2018-07-06 application/pdf http://hdl.handle.net/11250/2505077 https://doi.org/10.1371/journal.pone.0199842 eng eng Norges forskningsråd: 233858 Norges forskningsråd: 244444 urn:issn:1932-6203 http://hdl.handle.net/11250/2505077 https://doi.org/10.1371/journal.pone.0199842 cristin:1596293 Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no © 2018 Bloecher et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. CC-BY PLoS ONE Journal article Peer reviewed 2018 ftsintef https://doi.org/10.1371/journal.pone.0199842 2021-08-04T11:59:06Z This study examines the potential implications of biofouling management on the development of an infectious disease in Norwegian farmed salmon. The hydroid Ectopleura larynx frequently colonises cage nets at high densities (thousands of colonies per m2) and is released into the water during regular in-situ net cleaning. Contact with the hydroids’ nematocysts has the potential to cause irritation and pathological damage to salmon gills. Amoebic gill disease (AGD), caused by the amoeba Paramoeba perurans, is an increasingly international health challenge in Atlantic salmon farming. AGD often occurs concomitantly with other agents of gill disease. This study used laboratory challenge trials to: (1) characterise the gill pathology resulting from the exposure of salmon to hydroids, and (2) investigate if such exposure can predispose the fish to secondary infections–using P. perurans as an example. Salmon in tanks were exposed either to freshly ‘shredded’ hydroids resembling waste material from net cleaning, or to authentic concentrations of free-living P. perurans, or first to ‘shredded’ hydroids and then to P. perurans. Gill health (AGD gill scores, non-specific gill scores, lamellar thrombi, epithelial hyperplasia) was monitored over 5 weeks and compared to an untreated control group. Nematocysts of E. larynx contained in cleaning waste remained active following high-pressure cleaning, resulting in higher non-specific gill scores in salmon up to 1 day after exposure to hydroids. Higher average numbers of gill lamellar thrombi occurred in fish up to 7 days after exposure to hydroids. However, gill lesions caused by hydroids did not affect the infection rates of P. perurans or the disease progression of AGD. This study discusses the negative impacts hydroids and current net cleaning practices can have on gill health and welfare of farmed salmon, highlights existing knowledge gaps and reiterates the need for alternative approaches to net cleaning. This study was funded by the Research Council of Norway through a postdoctoral grant (NFR 244444/E40) for NB, and a research grant (NFR 233858/E40) for the members of the Norwegian Veterinary Institute (AGG, SH, MG, JWN, SNM, HH) and the Norwegian Institute for Water Research NIVA (MP, JJ). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. publishedVersion Article in Journal/Newspaper Atlantic salmon SINTEF Open (Brage) Norway Niva ENVELOPE(23.913,23.913,66.136,66.136) PLOS ONE 13 7 e0199842 |
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Open Polar |
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SINTEF Open (Brage) |
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English |
description |
This study examines the potential implications of biofouling management on the development of an infectious disease in Norwegian farmed salmon. The hydroid Ectopleura larynx frequently colonises cage nets at high densities (thousands of colonies per m2) and is released into the water during regular in-situ net cleaning. Contact with the hydroids’ nematocysts has the potential to cause irritation and pathological damage to salmon gills. Amoebic gill disease (AGD), caused by the amoeba Paramoeba perurans, is an increasingly international health challenge in Atlantic salmon farming. AGD often occurs concomitantly with other agents of gill disease. This study used laboratory challenge trials to: (1) characterise the gill pathology resulting from the exposure of salmon to hydroids, and (2) investigate if such exposure can predispose the fish to secondary infections–using P. perurans as an example. Salmon in tanks were exposed either to freshly ‘shredded’ hydroids resembling waste material from net cleaning, or to authentic concentrations of free-living P. perurans, or first to ‘shredded’ hydroids and then to P. perurans. Gill health (AGD gill scores, non-specific gill scores, lamellar thrombi, epithelial hyperplasia) was monitored over 5 weeks and compared to an untreated control group. Nematocysts of E. larynx contained in cleaning waste remained active following high-pressure cleaning, resulting in higher non-specific gill scores in salmon up to 1 day after exposure to hydroids. Higher average numbers of gill lamellar thrombi occurred in fish up to 7 days after exposure to hydroids. However, gill lesions caused by hydroids did not affect the infection rates of P. perurans or the disease progression of AGD. This study discusses the negative impacts hydroids and current net cleaning practices can have on gill health and welfare of farmed salmon, highlights existing knowledge gaps and reiterates the need for alternative approaches to net cleaning. This study was funded by the Research Council of Norway through a postdoctoral grant (NFR 244444/E40) for NB, and a research grant (NFR 233858/E40) for the members of the Norwegian Veterinary Institute (AGG, SH, MG, JWN, SNM, HH) and the Norwegian Institute for Water Research NIVA (MP, JJ). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Bloecher, Nina Powell, Mark Hytterød, Sigurd Gjessing, Mona Cecilie Wiik-Nielsen, Jannicke Mohammad, Saima Hansen, Haakon Floerl, Oliver Gjevre, Anne Gerd |
spellingShingle |
Bloecher, Nina Powell, Mark Hytterød, Sigurd Gjessing, Mona Cecilie Wiik-Nielsen, Jannicke Mohammad, Saima Hansen, Haakon Floerl, Oliver Gjevre, Anne Gerd Effects of cnidarian biofouling on salmon gill health and development of amoebic gill disease |
author_facet |
Bloecher, Nina Powell, Mark Hytterød, Sigurd Gjessing, Mona Cecilie Wiik-Nielsen, Jannicke Mohammad, Saima Hansen, Haakon Floerl, Oliver Gjevre, Anne Gerd |
author_sort |
Bloecher, Nina |
title |
Effects of cnidarian biofouling on salmon gill health and development of amoebic gill disease |
title_short |
Effects of cnidarian biofouling on salmon gill health and development of amoebic gill disease |
title_full |
Effects of cnidarian biofouling on salmon gill health and development of amoebic gill disease |
title_fullStr |
Effects of cnidarian biofouling on salmon gill health and development of amoebic gill disease |
title_full_unstemmed |
Effects of cnidarian biofouling on salmon gill health and development of amoebic gill disease |
title_sort |
effects of cnidarian biofouling on salmon gill health and development of amoebic gill disease |
publishDate |
2018 |
url |
http://hdl.handle.net/11250/2505077 https://doi.org/10.1371/journal.pone.0199842 |
long_lat |
ENVELOPE(23.913,23.913,66.136,66.136) |
geographic |
Norway Niva |
geographic_facet |
Norway Niva |
genre |
Atlantic salmon |
genre_facet |
Atlantic salmon |
op_source |
PLoS ONE |
op_relation |
Norges forskningsråd: 233858 Norges forskningsråd: 244444 urn:issn:1932-6203 http://hdl.handle.net/11250/2505077 https://doi.org/10.1371/journal.pone.0199842 cristin:1596293 |
op_rights |
Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no © 2018 Bloecher et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1371/journal.pone.0199842 |
container_title |
PLOS ONE |
container_volume |
13 |
container_issue |
7 |
container_start_page |
e0199842 |
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