Comparisons of Underwater Light From Atmospheric and Mechanically Stimulated Bioluminescence Sources in High Arctic Polar Night
Date
2024-04-29
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Geophysical Research: Oceans
Abstract
At high latitudes, polar night is a prolonged period of seasonal darkness with the sun remaining below the horizon throughout the diel cycle for up to 177 days at the North Pole. Along with diffuse atmospheric light from the sun and the moon, bioluminescence is an in-water light source that can facilitate ecological interactions in an otherwise dim-light environment. At high latitudes during polar night, bioluminescence rather than sunlight represents a significant portion of the photons available in the pelagic. We investigated depths of transition zones (called the bioluminescence transition depth) in the pelagic light field during polar night, defining the transition of a light field dominated by atmospheric irradiance, to one dominated by bioluminescent point sources. We derived relationships between values of the transition depth, bioluminescence potential, surface irradiance due to atmospheric light and the diffuse attenuation coefficient. We conducted studies for two Svalbard, Norway fjords, as well as for offshore areas located in the shelf-break, shelf-slope and in the Arctic basin. Based on our results for two polar nights, the transition from underwater light dominated by atmospheric sources to that dominated by bioluminescence occurs between 10 and 40 m in two Svalbard fjords, and between 18 and 60 m for offshore areas. These transition depths may be of particular importance to understanding how bioluminescence structures planktonic communities both in polar regions and at lower latitudes.
Key Points
- We investigated depths of transition zones from one dominated by atmospheric irradiance to one dominated by bioluminescent sources
- We derived relationships between transition depth, bioluminescence potential, surface irradiance and diffuse attenuation coefficient
- At high latitudes during polar night, bioluminescence represents a significant portion of the photons available in the pelagic
Plain Language Summary
The polar night is a period of continuous winter darkness north of ∼72.5°N latitude, and this period presents challenging light conditions for Arctic pelagic organisms. With the sun remaining below the horizon from one day at the Arctic Circle to 6 months at the North Pole, prolonged darkness limits light-mediated predator prey interactions in the plankton. Bioluminescence is light produced by a photochemical reaction in organisms, and it is an in-water light source that can facilitate ecological interactions in an otherwise dim-light environment. We investigated depths of transition zones from a light field dominated by atmospheric irradiance, to one dominated by bioluminescent point sources, across a gradient from Svalbard fjords to the Arctic basin. Based on our results, the transition from underwater light dominated by atmospheric sources to that dominated by bioluminescence occurs between 10 and 40 m in two Svalbard fjords, and between 18 and 60 m for offshore areas. The light gradient occurring in these transition zones has ecological implications, including depth selection and predator-prey interactions. This work provides another step in the difficult task of untangling the complex relationships among marine organisms and natural light.
Description
This article was originally published in Journal of Geophysical Research: Oceans. The version of record is available at: https://doi.org/10.1029/2023JC020135. © 2024. The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Data Availability Statement
Data can be downloaded from: https://udspace.udel.edu/handle/19716/33846
Keywords
bioluminescence, Arctic, polar night, underwater light, Svalbard
Citation
Shulman, I., Cohen, J. H., Anderson, S., Penta, B., & Moline, M. A. (2024). Comparisons of underwater light from atmospheric and mechanically stimulated bioluminescence sources in high Arctic polar night. Journal of Geophysical Research: Oceans, 129, e2023JC020135. https://doi.org/10.1029/2023JC020135