Browsing by Author "Anderson, Stephanie"
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Item Comparisons of Underwater Light From Atmospheric and Mechanically Stimulated Bioluminescence Sources in High Arctic Polar Night(Journal of Geophysical Research: Oceans, 2024-04-29) Shulman, Igor; Cohen, Jonathan H.; Anderson, Stephanie; Penta, Bradley; Moline, Mark A.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.Item CTD and UBAT data from: Comparisons of underwater light from atmospheric and mechanically stimulated bioluminescence sources in high Arctic Polar Night(2024-01-22) Shulman, Igor; Cohen, Jonathan H.; Anderson, Stephanie; Penta, Bradley; Moline, Mark A.For each station, we profiled an instrumented cage from the surface to 120 m (bottom depth ≈ 200 m). The cage was equipped with a bathyphotometer (UBAT–Underwater Bioluminescence Assessment Tool, WetLabs, Philomath, OR) and CTD (SBE 49 FastCAT, Sea-Bird, Bellevue, WA). For each cast, we held instruments for 4 min at every 20 m depth interval to measure bioluminescence. Fjord sampling in January 2014 (A2014, B2014, C2014, D2014) was conducted in Kongsfjord, Svalbard (78° 56.16'N, 11° 56.58'E). For more detail on this data collection see: Cronin et al. (2016) Scientific Reports 6:36374, DOI: 10.1038/srep36374 Fjord sampling in January 2017 (A2017) was conducted in Rijpfjorden, Svalbard (80° 18.261'N / 02° 215.705'E). For more detail on this data collection see: Shulman et al. (2020) Ocean Dynamics 70:1211–1223, https://doi.org/10.1007/s10236-020-01392-2 Shelf/slope sampling in January 2017 (B2017, C2017) was conducted offshore from Rijpfjorden, Svalbard (80° 55.364'N / 017°32.469E, 80°35.923'N / 013°40.636'E). For more detail on this data collection see: Shulman et al. (2020) Ocean Dynamics 70:1211–1223, https://doi.org/10.1007/s10236-020-01392-2 Arctic basin sampling in January 2017 (D2017) was conducted further offshore of Rijpfjorden, Svalbard (81°21.285'N / 014°51.079'E). For more detail on this data collection see: Shulman et al. (2020) Ocean Dynamics 70:1211–1223, https://doi.org/10.1007/s10236-020-01392-2 The separate tabs in this spreadsheet correspond to each sampling location described above. CTD and UBAT data are included, with bioluminescence data provided as both 1 second averages and at 60Hz resolution Parameters and units for the profile at each station from merged CTD and UBAT records are: Time (ms) Record number (NA) Temp (C) Depth (m) Salinity (psu) Calibration Coeff for HV step (photons/s) Avg BL (photons/s) Pump RPM (RPM) System Voltage (V) Flow RPM (RPM) HV step (V) 60Hzdata_n [60 Hz digitized raw A/D counts, n=1-60] (photons)