Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient
Throughout the oceans, small fish and other micronekton migrate between daytime depths of several hundred meters and near-surface waters at night. These diel vertical migrations of mesopelagic organisms structure pelagic ecosystems through trophic interactions, and are a key element in the biologica...
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Online Access: | https://hdl.handle.net/1956/23680 https://doi.org/10.3354/meps13024 |
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ftunivbergen:oai:bora.uib.no:1956/23680 2023-05-15T17:47:07+02:00 Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient Langbehn, Tom Aksnes, Dag Lorents Kaartvedt, Stein Fiksen, Øyvind Jørgensen, Christian 2019-11-15T10:06:50Z application/pdf https://hdl.handle.net/1956/23680 https://doi.org/10.3354/meps13024 eng eng Inter-Research urn:issn:0171-8630 urn:issn:1616-1599 https://hdl.handle.net/1956/23680 https://doi.org/10.3354/meps13024 cristin:1721510 Attribution CC BY http://creativecommons.org/licenses/by/4.0 Copyright 2019 The Author(s) Marine Ecology Progress Series Peer reviewed Journal article 2019 ftunivbergen https://doi.org/10.3354/meps13024 2023-03-14T17:44:36Z Throughout the oceans, small fish and other micronekton migrate between daytime depths of several hundred meters and near-surface waters at night. These diel vertical migrations of mesopelagic organisms structure pelagic ecosystems through trophic interactions, and are a key element in the biological carbon pump. However, depth distributions and migration amplitude vary greatly. Suggested proximate causes of the migration such as oxygen, temperature, and light often correlate and therefore the causal underpinnings have remained unclear. Using mesopelagic fishes and the Norwegian Sea as a study system, we developed a dynamic state variable model that finds optimal migration patterns that we validate with acoustic observations along a latitudinal gradient. The model describes predation risk and bioenergetics, and maximizes expected energy surplus, a proxy for Darwinian fitness. The model allows us to disentangle the drivers of migration and make predictions about depth distribution and related fitness consequences along a latitudinal trajectory with strong gradients in environmental drivers and vertical distribution of scattering layers. We show that the model-predicted vertical migration of mesopelagic fishes matches that observed along this transect. For most situations, modelled mesopelagic fish behaviour can be well described by a light comfort zone near identical to that derived from observations. By selectively keeping light or temperature constant, the model reveals that temperature, in comparison with light, has little effect on depth distribution. We find that water clarity, which limits how deeply light can penetrate into the ocean, structures daytime depths, while surface light at night controlled the depth of nocturnal ascents. publishedVersion Article in Journal/Newspaper Norwegian Sea University of Bergen: Bergen Open Research Archive (BORA-UiB) Norwegian Sea Marine Ecology Progress Series 623 161 174 |
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Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
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ftunivbergen |
language |
English |
description |
Throughout the oceans, small fish and other micronekton migrate between daytime depths of several hundred meters and near-surface waters at night. These diel vertical migrations of mesopelagic organisms structure pelagic ecosystems through trophic interactions, and are a key element in the biological carbon pump. However, depth distributions and migration amplitude vary greatly. Suggested proximate causes of the migration such as oxygen, temperature, and light often correlate and therefore the causal underpinnings have remained unclear. Using mesopelagic fishes and the Norwegian Sea as a study system, we developed a dynamic state variable model that finds optimal migration patterns that we validate with acoustic observations along a latitudinal gradient. The model describes predation risk and bioenergetics, and maximizes expected energy surplus, a proxy for Darwinian fitness. The model allows us to disentangle the drivers of migration and make predictions about depth distribution and related fitness consequences along a latitudinal trajectory with strong gradients in environmental drivers and vertical distribution of scattering layers. We show that the model-predicted vertical migration of mesopelagic fishes matches that observed along this transect. For most situations, modelled mesopelagic fish behaviour can be well described by a light comfort zone near identical to that derived from observations. By selectively keeping light or temperature constant, the model reveals that temperature, in comparison with light, has little effect on depth distribution. We find that water clarity, which limits how deeply light can penetrate into the ocean, structures daytime depths, while surface light at night controlled the depth of nocturnal ascents. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Langbehn, Tom Aksnes, Dag Lorents Kaartvedt, Stein Fiksen, Øyvind Jørgensen, Christian |
spellingShingle |
Langbehn, Tom Aksnes, Dag Lorents Kaartvedt, Stein Fiksen, Øyvind Jørgensen, Christian Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient |
author_facet |
Langbehn, Tom Aksnes, Dag Lorents Kaartvedt, Stein Fiksen, Øyvind Jørgensen, Christian |
author_sort |
Langbehn, Tom |
title |
Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient |
title_short |
Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient |
title_full |
Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient |
title_fullStr |
Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient |
title_full_unstemmed |
Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient |
title_sort |
light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient |
publisher |
Inter-Research |
publishDate |
2019 |
url |
https://hdl.handle.net/1956/23680 https://doi.org/10.3354/meps13024 |
geographic |
Norwegian Sea |
geographic_facet |
Norwegian Sea |
genre |
Norwegian Sea |
genre_facet |
Norwegian Sea |
op_source |
Marine Ecology Progress Series |
op_relation |
urn:issn:0171-8630 urn:issn:1616-1599 https://hdl.handle.net/1956/23680 https://doi.org/10.3354/meps13024 cristin:1721510 |
op_rights |
Attribution CC BY http://creativecommons.org/licenses/by/4.0 Copyright 2019 The Author(s) |
op_doi |
https://doi.org/10.3354/meps13024 |
container_title |
Marine Ecology Progress Series |
container_volume |
623 |
container_start_page |
161 |
op_container_end_page |
174 |
_version_ |
1766151433823977472 |