How to obtain clear images from in-trawl cameras near the seabed? A case study from the Barents Sea demersal fishing grounds
Underwater camera systems are commonly used for monitoring fish and fishing gear behaviours. More recently, camera systems have been applied to scientific trawl surveys for improved spatial resolution and less invasive sampling and to commercial fisheries for better catch control and reduced by-catc...
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Online Access: | https://hdl.handle.net/11250/3096856 https://doi.org/10.1016/j.fishres.2023.106856 |
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ftimr:oai:imr.brage.unit.no:11250/3096856 2023-11-12T04:15:03+01:00 How to obtain clear images from in-trawl cameras near the seabed? A case study from the Barents Sea demersal fishing grounds Tenningen, Maria Rosen, Shale Westergerling, Eugenie Heliana Taraneh Handegard, Nils Olav 2023 application/pdf https://hdl.handle.net/11250/3096856 https://doi.org/10.1016/j.fishres.2023.106856 eng eng https://crimac.no/nyheter/new-crimac-article-in-fisheries-research Norges forskningsråd: 309512 Fisheries Research. 2023, 268 . urn:issn:0165-7836 https://hdl.handle.net/11250/3096856 https://doi.org/10.1016/j.fishres.2023.106856 cristin:2184446 9 268 Fisheries Research Peer reviewed Journal article 2023 ftimr https://doi.org/10.1016/j.fishres.2023.106856 2023-10-18T22:47:26Z Underwater camera systems are commonly used for monitoring fish and fishing gear behaviours. More recently, camera systems have been applied to scientific trawl surveys for improved spatial resolution and less invasive sampling and to commercial fisheries for better catch control and reduced by-catch. A challenge when using cameras in demersal trawls is poor image clarity due to the door and ground gear generated sediment plume. In this study we have measured the height of the sediment plume produced by a large commercial trawl in the Barents Sea using acoustic methods and investigated its effect on in-trawl camera image clarity. The trawl extension was lengthened, and additional buoyancy added to lift the camera system in the aft end of the trawl. The camera system was tested at increasing heights above seabed until no sediment plume was visible in the images. Based on the acoustic data the sediment plume was measured to be on average 4–5 m (SD 1.7 m) above sea floor. Image clarity improved significantly as the camera system clearance from seabed increased from 4 to 11 m. No effect of sediment type on image clarity was identified. The trawl modifications did not affect the trawl’s opening geometry or bottom contact. However, the increased length and angle of the under panel aft in the trawl and in the extension appears to have resulted in reduced water flow and may influence the passage and retention of fish. The feasibility of using camera systems in demersal trawls and this and other solutions for obtaining clear images are discussed. How to obtain clear images from in-trawl cameras near the seabed? A case study from the Barents Sea demersal fishing grounds publishedVersion Article in Journal/Newspaper Barents Sea Institute for Marine Research: Brage IMR Barents Sea Fisheries Research 268 106856 |
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Open Polar |
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Institute for Marine Research: Brage IMR |
op_collection_id |
ftimr |
language |
English |
description |
Underwater camera systems are commonly used for monitoring fish and fishing gear behaviours. More recently, camera systems have been applied to scientific trawl surveys for improved spatial resolution and less invasive sampling and to commercial fisheries for better catch control and reduced by-catch. A challenge when using cameras in demersal trawls is poor image clarity due to the door and ground gear generated sediment plume. In this study we have measured the height of the sediment plume produced by a large commercial trawl in the Barents Sea using acoustic methods and investigated its effect on in-trawl camera image clarity. The trawl extension was lengthened, and additional buoyancy added to lift the camera system in the aft end of the trawl. The camera system was tested at increasing heights above seabed until no sediment plume was visible in the images. Based on the acoustic data the sediment plume was measured to be on average 4–5 m (SD 1.7 m) above sea floor. Image clarity improved significantly as the camera system clearance from seabed increased from 4 to 11 m. No effect of sediment type on image clarity was identified. The trawl modifications did not affect the trawl’s opening geometry or bottom contact. However, the increased length and angle of the under panel aft in the trawl and in the extension appears to have resulted in reduced water flow and may influence the passage and retention of fish. The feasibility of using camera systems in demersal trawls and this and other solutions for obtaining clear images are discussed. How to obtain clear images from in-trawl cameras near the seabed? A case study from the Barents Sea demersal fishing grounds publishedVersion |
format |
Article in Journal/Newspaper |
author |
Tenningen, Maria Rosen, Shale Westergerling, Eugenie Heliana Taraneh Handegard, Nils Olav |
spellingShingle |
Tenningen, Maria Rosen, Shale Westergerling, Eugenie Heliana Taraneh Handegard, Nils Olav How to obtain clear images from in-trawl cameras near the seabed? A case study from the Barents Sea demersal fishing grounds |
author_facet |
Tenningen, Maria Rosen, Shale Westergerling, Eugenie Heliana Taraneh Handegard, Nils Olav |
author_sort |
Tenningen, Maria |
title |
How to obtain clear images from in-trawl cameras near the seabed? A case study from the Barents Sea demersal fishing grounds |
title_short |
How to obtain clear images from in-trawl cameras near the seabed? A case study from the Barents Sea demersal fishing grounds |
title_full |
How to obtain clear images from in-trawl cameras near the seabed? A case study from the Barents Sea demersal fishing grounds |
title_fullStr |
How to obtain clear images from in-trawl cameras near the seabed? A case study from the Barents Sea demersal fishing grounds |
title_full_unstemmed |
How to obtain clear images from in-trawl cameras near the seabed? A case study from the Barents Sea demersal fishing grounds |
title_sort |
how to obtain clear images from in-trawl cameras near the seabed? a case study from the barents sea demersal fishing grounds |
publishDate |
2023 |
url |
https://hdl.handle.net/11250/3096856 https://doi.org/10.1016/j.fishres.2023.106856 |
geographic |
Barents Sea |
geographic_facet |
Barents Sea |
genre |
Barents Sea |
genre_facet |
Barents Sea |
op_source |
9 268 Fisheries Research |
op_relation |
https://crimac.no/nyheter/new-crimac-article-in-fisheries-research Norges forskningsråd: 309512 Fisheries Research. 2023, 268 . urn:issn:0165-7836 https://hdl.handle.net/11250/3096856 https://doi.org/10.1016/j.fishres.2023.106856 cristin:2184446 |
op_doi |
https://doi.org/10.1016/j.fishres.2023.106856 |
container_title |
Fisheries Research |
container_volume |
268 |
container_start_page |
106856 |
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1782332510942789632 |