scholarly journals Bioconditioning of Arctic Waters and Stimulation of Arctic Phytoplankton by Sea Ice Algae: Vulnerability to Increased Light

ARCTIC ◽  
2020 ◽  
Vol 73 (1) ◽  
pp. 114-117
Author(s):  
Spencer Apollonio
Keyword(s):  
Sea Ice ◽  
Early Summer ◽  
Arctic Sea Ice ◽  
Phytoplankton Production ◽  
Ice Algae ◽  
Light Conditions ◽  
Low Light ◽  
Sea Ice Algae ◽  
Arctic Sea ◽  
Summer Growth

Arctic sea ice algae produce extracellular organic products, which, as bioconditioners of seawater, may stimulate early summer growth of pelagic, under-sea-ice phytoplankton in low light and low temperature conditions. Sea ice algae are inhibited or decline in numbers if prematurely exposed to high light conditions, thereby reducing their ability to produce bioconditioners. As climate change creates an early reduction or removal of snow and sea ice cover, the result may be a decrease in primary phytoplankton production.

Arctic sea ice algae differ markedly from phytoplankton in their ecophysiological characteristics

2021 ◽  
Author(s):  
AC Kvernvik ◽  
CJM Hoppe ◽  
M Greenacre ◽  
S Verbiest ◽  
JM Wiktor ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Ice Algae ◽  
Sea Ice Algae ◽  
Arctic Sea

scholarly journals Monitoring abiotic degradation in sinking versus suspended Arctic sea ice algae during a spring ice melt using specific lipid oxidation tracers

2016 ◽  
Vol 98 ◽  
pp. 82-97 ◽  
Author(s):  
Jean-François Rontani ◽  
Simon T. Belt ◽  
Thomas A. Brown ◽  
Rémi Amiraux ◽  
Michel Gosselin ◽  
...  
Keyword(s):  
Sea Ice ◽  
Lipid Oxidation ◽  
Arctic Sea Ice ◽  
Ice Algae ◽  
Ice Melt ◽  
Sea Ice Algae ◽  
Abiotic Degradation ◽  
Arctic Sea ◽  
Specific Lipid

scholarly journals Pigment composition and photoprotection of Arctic sea ice algae during spring

2017 ◽  
Vol 585 ◽  
pp. 49-69 ◽  
Author(s):  
V Galindo ◽  
M Gosselin ◽  
J Lavaud ◽  
CJ Mundy ◽  
B Else ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Ice Algae ◽  
Pigment Composition ◽  
Sea Ice Algae ◽  
Arctic Sea

scholarly journals Low Fe Availability for Photosynthesis of Sea-Ice Algae: Ex situ Incubation of the Ice Diatom Fragilariopsis cylindrus in Low-Fe Sea Ice Using an Ice Tank

2021 ◽  
Vol 8 ◽  
Author(s):  
Kazuhiro Yoshida ◽  
Andreas Seger ◽  
Matthew Corkill ◽  
Petra Heil ◽  
Kristen Karsh ◽  
...  
Keyword(s):  
Sea Ice ◽  
High Light ◽  
Freezing Stress ◽  
Ex Situ ◽  
Ice Algae ◽  
Light Conditions ◽  
Low Light ◽  
Ice Melt ◽  
Sea Ice Algae ◽  
Fragilariopsis Cylindrus

Sea-ice algae play a crucial role in the ecology and biogeochemistry of sea-ice zones. They not only comprise the base of sea-ice ecosystems, but also seed populations of extensive ice-edge blooms during ice melt. Ice algae must rapidly acclimate to dynamic light environments, from the low light under sea ice to high light within open waters. Recently, iron (Fe) deficiency has been reported for diatoms in eastern Antarctic pack ice. Low Fe availability reduces photosynthetic plasticity, leading to reduced ice-algal primary production. We developed a low-Fe ice tank to manipulate Fe availability in sea ice. Over 20 days in the ice tank, the Antarctic ice diatom Fragilariopsis cylindrus was incubated in artificial low-Fe sea ice ([total Fe] = 20 nM) in high light (HL) and low light (LL) conditions. Melted ice was also exposed to intense light to simulate light conditions typical for melting ice in situ. When diatoms were frozen in, the maximum photochemical quantum efficiency of photosystem II (PSII), Fv/Fm, was suppressed by freezing stress. However, the diatoms maintained photosynthetic capability throughout the ice periods with a stable Fv/Fm value and increased photoprotection through non-photochemical quenching (NPQ) via photoprotective xanthophyll cycling (XC) and increased photoprotective carotenoid levels compared to pre-freeze-up. Photoprotection was more pronounced in the HL treatment due to greater light stress. However, the functional absorption cross section of PSII, σPSII, in F. cylindrus consistently increased after freezing, especially in the LL treatment (σPSII > 10 nm2 PSII–1). Our study is the first to report such a large σPSII in ice diatoms at low Fe conditions. When the melted sea ice was exposed to high light, Fv/Fm was suppressed. NPQ and XC were slightly upregulated, but not to values normally observed when Fe is not limiting, which indicates reduced photosynthetic flexibility to adapt to environmental changes during ice melt under low Fe conditions. Although ice algae can optimize their photosynthesis to sea-ice environments, chronic Fe starvation led to less flexibility of photoacclimation, particularly in low light conditions. This may have detrimental consequences for ice algal production and trophic interactions in sea-ice ecosystems if the recent reduction in sea-ice extent continues.

Effects of increased irradiance on biomass, photobiology, nutritional quality, and pigment composition of Arctic sea ice algae

2020 ◽  
Vol 648 ◽  
pp. 95-110 ◽  
Author(s):  
LC Lund-Hansen ◽  
I Hawes ◽  
K Hancke ◽  
N Salmansen ◽  
JR Nielsen ◽  
...  
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Snow Cover ◽  
Nutritional Quality ◽  
Light Availability ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Ice Algae ◽  
Sea Ice Algae ◽  
Arctic Sea

Ice algae are key contributors to primary production and carbon fixation in the Arctic, and light availability is assumed to limit their growth and productivity. We investigated photo-physiological responses in sea ice algae to increased irradiance during a spring bloom in West Greenland. During a 14 d field experiment, light transmittance through sea ice was manipulated to provide 3 under-ice irradiance regimes: low (0.04), medium (0.08), and high (0.16) transmittances. Chlorophyll a decreased with elevated light availability relative to the control. Maximum dark-adapted photosynthetic efficiency (ΦPSII_max) showed an initially healthy and productive ice algae community (ΦPSII_max > 0.6), with ΦPSII_max decreasing markedly under high-light treatments. This was accompanied by a decrease in the light utilization coefficient (α) and photosynthetic capacity (maximum relative electron transfer rate), and a decrease in the ratio of mono- to polyunsaturated fatty acids. This was partly explained by a corresponding increase of photoprotective pigments (diadinoxanthin and diatoxanthin), and a development of mycosporine-like amino acids as identified from a distinctive spectral absorption peak at 360 nm. After 14 d, in situ fluorescence imaging revealed significant differences in ΦPSII_max between treatments of dark-adapted cells (i.e. those sampled before sunrise and after sunset), during diel cycles, with clear chronic photoinhibition in high and medium treatments. Data demonstrate the high sensitivity of spring-blooming Arctic sea ice algae to elevated irradiance caused by loss of snow cover. The predicted loss of snow cover on landfast ice will negatively impact ice algae, their potential primary production, and nutritional quality for higher trophic levels.

scholarly journals Modeling Arctic sea-ice algae: Physical drivers of spatial distribution and algae phenology

2017 ◽  
Vol 122 (9) ◽  
pp. 7466-7487 ◽  
Author(s):  
Giulia Castellani ◽  
Martin Losch ◽  
Benjamin A. Lange ◽  
Hauke Flores
Keyword(s):  
Spatial Distribution ◽  
Sea Ice ◽  
Arctic Sea Ice ◽  
Ice Algae ◽  
Sea Ice Algae ◽  
Arctic Sea

scholarly journals Windows in Arctic sea ice: Light transmission and ice algae in a refrozen lead

2017 ◽  
Vol 122 (6) ◽  
pp. 1486-1505 ◽  
Author(s):  
Hanna M. Kauko ◽  
Torbjørn Taskjelle ◽  
Philipp Assmy ◽  
Alexey K. Pavlov ◽  
C. J. Mundy ◽  
...  
Keyword(s):  
Sea Ice ◽  
Light Transmission ◽  
Arctic Sea Ice ◽  
Ice Algae ◽  
Arctic Sea

Thermal source Fourier transform infrared microtomography applied to Arctic sea ice diatoms

The Analyst ◽  
2017 ◽  
Vol 142 (4) ◽  
pp. 660-669 ◽  
Author(s):  
Catherine Findlay ◽  
Jason Morrison ◽  
C. J. Mundy ◽  
Julia Sedlmair ◽  
Carol J. Hirschmugl ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Sea Ice ◽  
Fourier Transform Infrared ◽  
Arctic Sea Ice ◽  
Thermal Source ◽  
Light Conditions ◽  
Arctic Sea

We have used thermal source Fourier Transform Infrared (FTIR) microtomographic imaging to compare sea ice diatoms growing under different light conditions.

scholarly journals Impacts of sea ice on the marine iron cycle and phytoplankton productivity

2014 ◽  
Vol 11 (2) ◽  
pp. 2383-2418 ◽  
Author(s):  
S. Wang ◽  
D. Bailey ◽  
K. Lindsay ◽  
K. Moore ◽  
M. Holland
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Phytoplankton Production ◽  
Iron Cycle ◽  
Surface Ocean ◽  
Antarctic Sea Ice ◽  
Arctic Sea ◽  
Iron Concentrations

Abstract. Iron is a key nutrient for phytoplankton growth in the surface ocean. At high latitudes, the iron cycle is closely related to sea ice. In recent decades, Arctic sea ice cover has been declining rapidly and Antarctic sea ice has exhibited large regional trends. A significant reduction of sea ice in both hemispheres is projected in future climate scenarios. To study impacts of sea ice on the iron cycle, iron sequestration in ice is incorporated to the Biogeochemical Elemental Cycling (BEC) model. Sea ice acts as a reservoir of iron during winter and releases iron to the surface ocean in spring and summer. Simulated iron concentrations in sea ice generally agree with observations, in regions where iron concentrations are lower. The maximum iron concentrations simulated in the Arctic sea ice and the Antarctic sea ice are 192 nM and 134 nM, respectively. These values are much lower than observed, which is likely due to missing biological processes in sea ice. The largest iron source to sea ice is suspended sediments, contributing fluxes of iron of 2.2 × 108 mol Fe month−1 to the Arctic and 4.1 × 106 mol Fe month−1 to the Southern Ocean during summer. As a result of the iron flux from ice, iron concentrations increase significantly in the Arctic. Iron released from melting ice increases phytoplankton production in spring and summer and shifts phytoplankton community composition in the Southern Ocean. Simulation results for the period of 1998 to 2007 indicate that a reduction of sea ice in the Southern Ocean will have a negative influence on phytoplankton production. Iron transport by sea ice appears to be an important process bringing iron to the central Arctic. Impacts of iron fluxes from ice to ocean on marine ecosystems are negligible in the current Arctic Ocean, as iron is not typically the growth-limiting nutrient. However, it may become a more important factor in the future, particularly in the central Arctic, as iron concentrations will decrease with declining sea ice cover and transport.

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