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 Effect of frequent winter warming events (storms) and snow on sea-ice growth – a case from the Atlantic sector of the Arctic Ocean during the N-ICE2015 campaign

2020 ◽  
Vol 61 (82) ◽  
pp. 164-170
Author(s):  
Ioanna Merkouriadi ◽  
Bin Cheng ◽  
Stephen R. Hudson ◽  
Mats A. Granskog
Keyword(s):  
Sea Ice ◽  
Snow Cover ◽  
Critical Role ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Winter Period ◽  
Storm Events ◽  
Atlantic Sector ◽  
Ice Growth ◽  
Arctic Sea

AbstractWe examine the relative effect of warming events (storms) and snow cover on thermodynamic growth of Arctic sea ice in winter. We use a 1-D snow and ice thermodynamic model to perform sensitivity experiments. Observations from the winter period of the Norwegian young sea ICE (N-ICE2015) campaign north of Svalbard are used to initiate and force the model. The N-ICE2015 winter was characterized by frequent storm events that brought pulses of heat and moisture, and a thick snow cover atop the sea ice (0.3–0.5 m). By the end of the winter, sea-ice bottom growth was negligible. We show that the thermodynamic effect of storms to the winter sea-ice growth is controlled by the amount of snow on sea ice. For 1.3 m initial ice thickness, the decrease in ice growth caused by the warming events ranged from −1.4% (for 0.5 m of snow) to −7.5% (for snow-free conditions). The decrease in sea-ice growth caused by the thick snow (0.5 m) was more important, ranging from −17% (with storms) to −23% (without storms). The results showcase the critical role of snow on winter Arctic sea-ice growth.

scholarly journals Production of Chromophoric Dissolved Organic Matter (CDOM) in Laboratory Cultures of Arctic Sea Ice Algae

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 926
Author(s):  
Guiju Li ◽  
Huixiang Xie ◽  
Guisheng Song ◽  
Michel Gosselin
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Sea Ice ◽  
Chlorophyll A ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Chromophoric Dissolved Organic Matter ◽  
Ice Algae ◽  
Production Rates ◽  
Arctic Sea

Chromophoric dissolved organic matter (CDOM) is highly enriched in bottom sea ice in the Arctic during ice algal blooms, giving rise to multifaceted ecological implications in both the sea ice and the underlying seawater. We conducted laboratory culture incubations to assess the potential role of ice algae in the accumulation of CDOM in Arctic sea ice. Non-axenic monocultures of Attheya septentrionalis and Nitzschia frigida and a natural ice algal assemblage (NIAA) were grown at 4 °C in an f/2 medium under cool white fluorescent light. Culture samples were collected several days apart throughout the exponential, stationary, and senescent phases, and analyzed for CDOM absorbance, chlorophyll a, and bacterial cell abundance. The cultures displayed apparent specific growth rates of algal and bacterial cells comparable to those in the field. Accumulations of CDOM were observed in all cultures during the time-course incubations, with the senescent phase showing the largest accumulations and the highest production rates. The senescent-phase production rate for NIAA was ~40% higher than that for A. septentrionalis. The chlorophyll a-normalized CDOM production rates in the cultures are comparable to those reported for Arctic first-year sea ice. The absorption spectra of CDOM in the cultures exhibited characteristic short-ultraviolet shoulders similar to those previously identified in sea ice. This study demonstrates that ice algal-derived CDOM can account for the springtime accumulation of CDOM in Arctic sea ice.

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 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.

Features of changes in the sea ice and snow cover extents associated with temperature changes in the Northern and Southern Hemispheres in recent decades.

2021 ◽  
Author(s):  
Maria Parfenova ◽  
Igor I. Mokhov
Keyword(s):  
Sea Ice ◽  
Surface Temperature ◽  
Snow Cover ◽  
Reanalysis Data ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
Arctic Sea ◽  
Northern And Southern Hemispheres

<p>Quantitative estimates of the relationship between the interannual variability of Antarctic and Arctic sea ice and changes in the surface temperature in the Northern and Southern Hemispheres using satellitedata, observational data and reanalysis data for the last four decades (1980-2019) are obtained. The previously noted general increase in the Antarctic sea ice extent (up to 2016) (according to satellite data available only since the late 1970s), happening simultaneously with global warming and rapid decrease in the Arctic sea ice extent, is associated with the regional manifestation of natural climate fluctuations with periods of up to several decades. The results of correlation and crosswavelet analysis indicate significant coherence and negative correlation of hemispheric surface temperature with not only Arctic,but also Antarctic sea ice extent in recent decades.</p><p>Seasonal and regional peculiarities of snow cover sensitivity to temperature regime changes in the Northern Hemisphere are noted with an assessment of changes in recent decades. Peculiarities of snow cover variability in Eurasia and North America are presented. In particular, the peculiarities of changes in snow cover during the autumn seasons are noted.</p>

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
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