Vertical Migration of Pelagic and Mesopelagic Scatterers From ADCP Backscatter Data in the Southern Norwegian Sea
Records of backscatter and vertical velocity obtained from moored Acoustic Doppler Current Profilers (ADCP) enabled new insights into the dynamics of deep scattering layers (DSLs) and diel vertical migration (DVM) of mesopelagic biomass between these deep layers and the near-surface photic zone in t...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2021-01-01
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| Series: | Frontiers in Marine Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2020.542386/full |
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| author | Boris Cisewski Hjálmar Hátún Inga Kristiansen Bogi Hansen Karin Margretha H. Larsen Sólvá Káradóttir Eliasen Jan Arge Jacobsen |
| author_facet | Boris Cisewski Hjálmar Hátún Inga Kristiansen Bogi Hansen Karin Margretha H. Larsen Sólvá Káradóttir Eliasen Jan Arge Jacobsen |
| author_sort | Boris Cisewski |
| collection | DOAJ |
| description | Records of backscatter and vertical velocity obtained from moored Acoustic Doppler Current Profilers (ADCP) enabled new insights into the dynamics of deep scattering layers (DSLs) and diel vertical migration (DVM) of mesopelagic biomass between these deep layers and the near-surface photic zone in the southern Norwegian Sea. The DSL exhibits characteristic vertical movement on inter-monthly time scales, which is associated with undulations of the main pycnocline between the warm Atlantic water and the underlying colder water masses. Timing of the DVM is closely linked to the day-night light cycle—decent from the photic zone just before sunrise and ascent immediately after sunset. Seasonal variations are also evident, with the highest DVM activity and lowest depth averaged mean volume backscatter strength (MVBS) during spring. This suggests that both oceanographic and optical conditions are driving the complex dynamics of pelagic and mesopelagic activity in this region. We hypothesize that the increased abundance of calanoid copepods in the near-surface layer during spring increases the motivation for vertical migration of pelagic and mesopelagic species, which therefore can explain the increased DVM activity during this season. |
| first_indexed | 2024-12-13T12:09:53Z |
| format | Article |
| id | doaj.art-ade3c0551cad4822a7c3672308a7a06c |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-12-13T12:09:53Z |
| publishDate | 2021-01-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-ade3c0551cad4822a7c3672308a7a06c2022-12-21T23:46:53ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452021-01-01710.3389/fmars.2020.542386542386Vertical Migration of Pelagic and Mesopelagic Scatterers From ADCP Backscatter Data in the Southern Norwegian SeaBoris Cisewski0Hjálmar Hátún1Inga Kristiansen2Bogi Hansen3Karin Margretha H. Larsen4Sólvá Káradóttir Eliasen5Jan Arge Jacobsen6Thünen-Institut für Seefischerei, Bremerhaven, GermanyFaroe Marine Research Institute, Tórshavn, Faroe IslandsFaroe Marine Research Institute, Tórshavn, Faroe IslandsFaroe Marine Research Institute, Tórshavn, Faroe IslandsFaroe Marine Research Institute, Tórshavn, Faroe IslandsFaroe Marine Research Institute, Tórshavn, Faroe IslandsFaroe Marine Research Institute, Tórshavn, Faroe IslandsRecords of backscatter and vertical velocity obtained from moored Acoustic Doppler Current Profilers (ADCP) enabled new insights into the dynamics of deep scattering layers (DSLs) and diel vertical migration (DVM) of mesopelagic biomass between these deep layers and the near-surface photic zone in the southern Norwegian Sea. The DSL exhibits characteristic vertical movement on inter-monthly time scales, which is associated with undulations of the main pycnocline between the warm Atlantic water and the underlying colder water masses. Timing of the DVM is closely linked to the day-night light cycle—decent from the photic zone just before sunrise and ascent immediately after sunset. Seasonal variations are also evident, with the highest DVM activity and lowest depth averaged mean volume backscatter strength (MVBS) during spring. This suggests that both oceanographic and optical conditions are driving the complex dynamics of pelagic and mesopelagic activity in this region. We hypothesize that the increased abundance of calanoid copepods in the near-surface layer during spring increases the motivation for vertical migration of pelagic and mesopelagic species, which therefore can explain the increased DVM activity during this season.https://www.frontiersin.org/articles/10.3389/fmars.2020.542386/fulldiel vertical migrationADCP backscatterseasonal cyclesdeep scattering layerSouthern Norwegian Seamesopelagic fish |
| spellingShingle | Boris Cisewski Hjálmar Hátún Inga Kristiansen Bogi Hansen Karin Margretha H. Larsen Sólvá Káradóttir Eliasen Jan Arge Jacobsen Vertical Migration of Pelagic and Mesopelagic Scatterers From ADCP Backscatter Data in the Southern Norwegian Sea Frontiers in Marine Science diel vertical migration ADCP backscatter seasonal cycles deep scattering layer Southern Norwegian Sea mesopelagic fish |
| title | Vertical Migration of Pelagic and Mesopelagic Scatterers From ADCP Backscatter Data in the Southern Norwegian Sea |
| title_full | Vertical Migration of Pelagic and Mesopelagic Scatterers From ADCP Backscatter Data in the Southern Norwegian Sea |
| title_fullStr | Vertical Migration of Pelagic and Mesopelagic Scatterers From ADCP Backscatter Data in the Southern Norwegian Sea |
| title_full_unstemmed | Vertical Migration of Pelagic and Mesopelagic Scatterers From ADCP Backscatter Data in the Southern Norwegian Sea |
| title_short | Vertical Migration of Pelagic and Mesopelagic Scatterers From ADCP Backscatter Data in the Southern Norwegian Sea |
| title_sort | vertical migration of pelagic and mesopelagic scatterers from adcp backscatter data in the southern norwegian sea |
| topic | diel vertical migration ADCP backscatter seasonal cycles deep scattering layer Southern Norwegian Sea mesopelagic fish |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2020.542386/full |
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