國立虎尾科技大學 |

Light Sensitivity of the Arctic Copepod Metridia longa During Midnight Sun and Polar Night.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Light Sensitivity of the Arctic Copepod Metridia longa During Midnight Sun and Polar Night./
Author:	Lightfoot, Meaghan.
Description:	1 online resource (83 pages)
Notes:	Source: Masters Abstracts International, Volume: 85-01.
Contained By:	Masters Abstracts International85-01.
Subject:	Biophysics. -
Online resource:	click for full text (PQDT)
ISBN:	9798379782061

Light Sensitivity of the Arctic Copepod Metridia longa During Midnight Sun and Polar Night.
Lightfoot, Meaghan.

Light Sensitivity of the Arctic Copepod Metridia longa During Midnight Sun and Polar Night. - 1 online resource (83 pages)

Source: Masters Abstracts International, Volume: 85-01.

Thesis (M.S.)--University of Delaware, 2023.

Includes bibliographical references

The Arctic is defined by a seasonal light regime extending between 24-hour light (Midnight Sun) and 24-hour dark (Polar Night). Light itself acts as an important cue for marine zooplankton, dictating their orientation/navigation and vertical migration, prey detection and predator avoidance, and population dynamics/reproductive strategies. Changes in the spectral, intensity, and duration components of downwelling irradiance during Midnight Sun and Polar Night contribute to the annual Arctic light climate, and to what characteristics of light are used for zooplankton visual processes. Additionally, as the Arctic region is warming at an alarming rate, the loss of annual sea ice and snow coverage is projected to increase incoming illumination into the water column, impacting zooplankton visual systems, trophic dynamics, and predator-prey interactions.Given the marked differences in annual light climate at high latitudes, the objective of this study was to determine the behavioral responses of zooplankton species to spectral and irradiance light stimuli during Midnight Sun and Polar Night. The copepod species Metridia longa copepods were selected as the target species for this research due to their biomass in Atlantic-Arctic waters, vertical migration behaviors, and bioluminescent capabilities. While Polar Night twilight peak emissions are blue dominant (λmax = 455 nm) there is a shift towards green light (λmax = 550 nm) availability during Midnight Sun due to spring phytoplankton blooms and suspended particulate matter in the water column. Therefore, it was hypothesized that copepods will exhibit a broad spectral response sensitivity in the blue-green wavelengths in order to compensate for the annual shifts in available spectra. Additionally, it is expected that M. longa copepods will have a heightened irradiance response during Polar Night compared to Midnight Sun. Zooplankton visual systems are often more sensitive in low light conditions, thus it is hypothesized that irradiance responses will be increased during Polar Night.Sampling took place in the Barents Sea in May 2022 (Midnight Sun) and January 2023 (Polar Night), with additional sampling in Kongsfjorden during Polar Night in January 2023. Light response/sensitivity was assessed on an individual basis in this study to provide insight into the individual variability in light sensitivity among M. longa copepods. This was accomplished using an adjustable, high throughput apparatus to test 64 individual zooplankton swimming behavior individually and simultaneously to spectral and irradiance light stimuli.Results suggest a consistent blue-green dominant spectral response between Midnight Sun and Polar Night to wavelengths ranging from 400 to 550nm, along with an increased irradiance response by an order of magnitude among Polar Night copepods compared to those tested during Midnight Sun. Additionally, irradiance response among M. longa copepods may vary with developmental stage, but are not dependent on location or temperature during Polar Night. From these results, it was determined that M. longa female copepods can detect light down to 119 m during Midnight Sun in the Barents Sea and 55 m in Kongsfjorden during Polar Night. These irradiance thresholds correspond to reported depths of zooplankton across seasons as they move vertically with isolumes.In a changing Arctic, loss of sea ice and snow attenuating incoming irradiance is predicted to increase the pelagic visual lightscape. Since light sensitivity was not temperature dependent in this study, thresholds of detectable light in the water column should not vary with climate change-related increases in water temperature. This suggests that zooplankton like M. longa may be forced deeper in the water column to maintain themselves in darkness. Future work should assess M. longa response sensitivities under a more climate-focused lens, and incorporate additional components like cameras and other sensor positions to the apparatus created for this study to provide a full picture to zooplankton behavior in response to light at high latitudes.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2024

Mode of access: World Wide Web

ISBN: 9798379782061Subjects--Topical Terms:

581576
Biophysics.
Subjects--Index Terms:

ArcticIndex Terms--Genre/Form:

554714
Electronic books.

Light Sensitivity of the Arctic Copepod Metridia longa During Midnight Sun and Polar Night.
LDR:05495ntm a2200409K 4500 001 1141393
005 20240315085525.5
006 m o d
007 cr mn ---uuuuu
008 250605s2023 xx obm 000 0 eng d
020 $a 9798379782061
035 $a (MiAaPQ)AAI30424844
035 $a AAI30424844
040 $a MiAaPQ $b eng $c MiAaPQ $d NTU
100 1 $a Lightfoot, Meaghan. $3 1465129
245 1 0 $a Light Sensitivity of the Arctic Copepod Metridia longa During Midnight Sun and Polar Night.
264 0 $c 2023
300 $a 1 online resource (83 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Masters Abstracts International, Volume: 85-01.
500 $a Advisor: Cohen, Jonathan.
502 $a Thesis (M.S.)--University of Delaware, 2023.
504 $a Includes bibliographical references
520 $a The Arctic is defined by a seasonal light regime extending between 24-hour light (Midnight Sun) and 24-hour dark (Polar Night). Light itself acts as an important cue for marine zooplankton, dictating their orientation/navigation and vertical migration, prey detection and predator avoidance, and population dynamics/reproductive strategies. Changes in the spectral, intensity, and duration components of downwelling irradiance during Midnight Sun and Polar Night contribute to the annual Arctic light climate, and to what characteristics of light are used for zooplankton visual processes. Additionally, as the Arctic region is warming at an alarming rate, the loss of annual sea ice and snow coverage is projected to increase incoming illumination into the water column, impacting zooplankton visual systems, trophic dynamics, and predator-prey interactions.Given the marked differences in annual light climate at high latitudes, the objective of this study was to determine the behavioral responses of zooplankton species to spectral and irradiance light stimuli during Midnight Sun and Polar Night. The copepod species Metridia longa copepods were selected as the target species for this research due to their biomass in Atlantic-Arctic waters, vertical migration behaviors, and bioluminescent capabilities. While Polar Night twilight peak emissions are blue dominant (λmax = 455 nm) there is a shift towards green light (λmax = 550 nm) availability during Midnight Sun due to spring phytoplankton blooms and suspended particulate matter in the water column. Therefore, it was hypothesized that copepods will exhibit a broad spectral response sensitivity in the blue-green wavelengths in order to compensate for the annual shifts in available spectra. Additionally, it is expected that M. longa copepods will have a heightened irradiance response during Polar Night compared to Midnight Sun. Zooplankton visual systems are often more sensitive in low light conditions, thus it is hypothesized that irradiance responses will be increased during Polar Night.Sampling took place in the Barents Sea in May 2022 (Midnight Sun) and January 2023 (Polar Night), with additional sampling in Kongsfjorden during Polar Night in January 2023. Light response/sensitivity was assessed on an individual basis in this study to provide insight into the individual variability in light sensitivity among M. longa copepods. This was accomplished using an adjustable, high throughput apparatus to test 64 individual zooplankton swimming behavior individually and simultaneously to spectral and irradiance light stimuli.Results suggest a consistent blue-green dominant spectral response between Midnight Sun and Polar Night to wavelengths ranging from 400 to 550nm, along with an increased irradiance response by an order of magnitude among Polar Night copepods compared to those tested during Midnight Sun. Additionally, irradiance response among M. longa copepods may vary with developmental stage, but are not dependent on location or temperature during Polar Night. From these results, it was determined that M. longa female copepods can detect light down to 119 m during Midnight Sun in the Barents Sea and 55 m in Kongsfjorden during Polar Night. These irradiance thresholds correspond to reported depths of zooplankton across seasons as they move vertically with isolumes.In a changing Arctic, loss of sea ice and snow attenuating incoming irradiance is predicted to increase the pelagic visual lightscape. Since light sensitivity was not temperature dependent in this study, thresholds of detectable light in the water column should not vary with climate change-related increases in water temperature. This suggests that zooplankton like M. longa may be forced deeper in the water column to maintain themselves in darkness. Future work should assess M. longa response sensitivities under a more climate-focused lens, and incorporate additional components like cameras and other sensor positions to the apparatus created for this study to provide a full picture to zooplankton behavior in response to light at high latitudes.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2024
538 $a Mode of access: World Wide Web
650 4 $a Biophysics. $3 581576
650 4 $a Aquatic sciences. $3 1178821
650 4 $a Biology. $3 599573
653 $a Arctic
653 $a Irradiance response
653 $a Metridia longa
653 $a Midnight Sun
653 $a Polar Night
653 $a Spectral response
655 7 $a Electronic books. $2 local $3 554714
690 $a 0306
690 $a 0786
690 $a 0792
710 2 $a University of Delaware. $b Marine Studies. $3 1185909
710 2 $a ProQuest Information and Learning Co. $3 1178819
773 0 $t Masters Abstracts International $g 85-01.
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=30424844 $z click for full text (PQDT)