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Julie Sansoulet, Michèle Therrien, Joseph Delgove, Guilhem Pouxviel, Julie Desriac, Noé Sardet, Jean-Paul Vanderlinden |
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An update on Inuit perceptions of their changing environment, Qikiqtaaluk (Baffin Island, Nunavut) |
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2020 |
Publication |
Elementa: Science of the Anthropocene |
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8 |
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1 |
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The Inuit of Qikiqtaaluk (Baffin Island) have developed a deep respect for their natural environment and are able to report not only changes in weather, ice, and natural resources but also changes in their communities as a result of climate change. The objective of this study was to shed light on how the impacts of climate change are currently perceived in the communities of Kanngiqtugaapik, Pangniqtuuq, and Qikiqtarjuaq. In order to construct a shared knowledge base, we conducted qualitative video interviews and participated in a hunting camp with multigenerational and multigender Inuit hunters and fishers. First, Inuit continue to see the world in which they cohabit with other living things, particularly animals, as a world that they cannot control on their own—a world they must adapt to, passing learning from one generation to the next. Second, they report that changes in the ice have been among the major and most important transformations to have occurred in recent decades. Observations made by these local populations also indicate changes in hunted species, with fewer caribou and narwhal, more birds, insects, and fish, including from more southerly regions, and an uncertainty about polar bear populations. Seal hunting remains stable, and this meat is still the most popular and healthy food, physically and psychologically. Third, sociological and economic changes (e.g., lifestyle change, monetary economies, quotas), in addition to environmental changes (e.g., climate change, species change), have had a significant impact on food harvesting activities as well as food consumption in the region. A final perspective concerns the needs of the Qikiqtaaluk communities to further develop collaboration with scientists. This need for partnership is not only perceived as a scientific necessity but also recognized by Inuit as essential to their communities, with some local leaders ready to work toward a fruitful collaboration. |
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2325-1026 |
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2325-1026 |
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8117 |
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Rémi Amiraux, Christopher Burot, Patricia Bonin, Guillaume Massé, Sophie Guasco, Marcel Babin, Frédéric Vaultier, Jean-François Rontani |
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Title |
Stress factors resulting from the Arctic vernal sea-ice melt: Impact on the viability of bacterial communities associated with sympagic algae |
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Year |
2020 |
Publication |
Elementa: Science of the Anthropocene |
Abbreviated Journal |
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Volume |
8 |
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1 |
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During sea-ice melt in the Arctic, primary production by sympagic (sea-ice) algae can be exported efficiently to the seabed if sinking rates are rapid and activities of associated heterotrophic bacteria are limited. Salinity stress due to melting ice has been suggested to account for such low bacterial activity. We further tested this hypothesis by analyzing samples of sea ice and sinking particles collected from May 18 to June 29, 2016, in western Baffin Bay as part of the Green Edge project. We applied a method not previously used in polar regions—quantitative PCR coupled to the propidium monoazide DNA-binding method—to evaluate the viability of bacteria associated with sympagic and sinking algae. We also measured cis-trans isomerase activity, known to indicate rapid bacterial response to salinity stress in culture studies, as well as free fatty acids known to be produced by algae as bactericidal compounds. The viability of sympagic-associated bacteria was strong in May (only approximately 10% mortality of total bacteria) and weaker in June (average mortality of 43%; maximum of 75%), with instances of elevated mortality in sinking particle samples across the time series (up to 72%). Short-term stress reflected by cis-trans isomerase activity was observed only in samples of sinking particles collected early in the time series. Following snow melt, however, and saturating levels of photosynthetically active radiation in June, we observed enhanced ice-algal production of bactericidal compounds (free palmitoleic acid; up to 4.8 mg L–1). We thus suggest that protection of sinking sympagic material from bacterial degradation early in a melt season results from low bacterial activity due to salinity stress, while later in the season, algal production of bactericidal compounds induces bacterial mortality. A succession of bacterial stressors during Arctic ice melt helps to explain the efficient export of sea-ice algal material to the seabed. |
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8118 |
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Gustavo Yunda-Guarin, Thomas A. Brown, Loïc N. Michel, Blanche Saint-Béat, Rémi Amiraux, Christian Nozais, Philippe Archambault |
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Title |
Reliance of deep-sea benthic macrofauna on ice-derived organic matter highlighted by multiple trophic markers during spring in Baffin Bay, Canadian Arctic |
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Journal |
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Year |
2020 |
Publication |
Elementa: Science of the Anthropocene |
Abbreviated Journal |
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Volume |
8 |
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1 |
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Benthic organisms depend primarily on seasonal pulses of organic matter from primary producers. In the Arctic, declines in sea ice due to warming climate could lead to changes in this food supply with as yet unknown effects on benthic trophic dynamics. Benthic consumer diets and food web structure were studied in a seasonally ice-covered region of Baffin Bay during spring 2016 at stations ranging in depth from 199 to 2,111 m. We used a novel combination of highly branched isoprenoid (HBI) lipid biomarkers and stable isotope ratios (δ13C, δ15N) to better understand the relationship between the availability of carbon sources in spring on the seafloor and their assimilation and transfer within the benthic food web. Organic carbon from sea ice (sympagic carbon [SC]) was an important food source for benthic consumers. The lipid biomarker analyses revealed a high relative contribution of SC in sediments (mean SC% ± standard deviation [SD] = 86% ± 16.0, n = 17) and in benthic consumer tissues (mean SC% ± SD = 78% ± 19.7, n = 159). We also detected an effect of sea-ice concentration on the relative contribution of SC in sediment and in benthic consumers. Cluster analysis separated the study region into three different zones according to the relative proportions of SC assimilated by benthic macrofauna. We observed variation of the benthic food web between zones, with increases in the width of the ecological niche in zones with less sea-ice concentration, indicating greater diversity of carbon sources assimilated by consumers. In zones with greater sea-ice concentration, the higher availability of SC increased the ecological role that primary consumers play in driving a stronger transfer of nutrients to higher trophic levels. Based on our results, SC is an important energy source for Arctic deep-sea benthos in Baffin Bay, such that changes in spring sea-ice phenology could alter benthic food-web structure. |
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8119 |
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Mathieu LeBlanc, Stéphane Gauthier, Svend Erik Garbus, Anders Mosbech, Louis Fortier |
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Title |
The co-distribution of Arctic cod and its seabird predators across the marginal ice zone in Baffin Bay |
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Year |
2019 |
Publication |
Elementa: Science of the Anthropocene |
Abbreviated Journal |
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Volume |
7 |
Issue |
1 |
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Arctic cod (Boreogadus saida) is the dominant pelagic fish in Arctic seas and a staple food of many arctic predators including several seabird species. Marginal ice zones are known as important feeding locations for seabirds. The hypothesis that thick-billed murre (Uria lomvia), northern fulmar (Fulmarus glacialis) and black-legged kittiwake (Rissa tridactyla) congregate in areas of high Arctic cod food resource and low ice concentration was tested at different spatial scales. Arctic cod biomass was estimated by hydroacoustics as a resource proxy, and seabirds were counted and sampled for stomach analysis along eight longitudinal transects across the marginal ice zone in southern Baffin Bay in June–July 2016. With increasing length, the epipelagic age-0 Arctic cod migrated from open waters to ice-covered areas. Subsequently, age-1 and age-2 Arctic cod tended to concentrate in a subsurface layer (40–100 m) within the epipelagic layer. Arctic cod 5.7–16.1 cm long (late age-0 to age-5) were the main fish prey of the three seabird species, which preferentially captured age-1 cod (6–11.5 cm). At large spatial scale (western versus eastern Baffin Bay), thick-billed murre, northern fulmar and their Arctic cod resource proxy were generally more abundant on the western ice-covered side of Baffin Bay. No clear spatial match was found, however, when comparing seabird abundances and their food-resource proxy in different ice concentrations across the marginal ice zone or at small scale (5 km). At medium scale (12.5 km), only murre density was influenced positively by its Arctic cod resource. A lack of schooling behavior and a successful strategy to avoid predation by hiding under the ice could explain the absence of any strong spatial match between Arctic cod and its seabird predators at these different scales. |
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8121 |
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Achim Randelhoff, Laurent Oziel, Philippe Massicotte, Guislain Bécu, Martí Galí, Léo Lacour, Dany Dumont, Anda Vladoiu, Claudie Marec, Flavienne Bruyant, Marie-Noëlle Houssais, Jean-Éric Tremblay, Gabrièle Deslongchamps, Marcel Babin |
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Title |
The evolution of light and vertical mixing across a phytoplankton ice-edge bloom |
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Year |
2019 |
Publication |
Elementa: Science of the Anthropocene |
Abbreviated Journal |
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Volume |
7 |
Issue |
20 |
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During summer, phytoplankton can bloom in the Arctic Ocean, both in open water and under ice, often strongly linked to the retreating ice edge. There, the surface ocean responds to steep lateral gradients in ice melt, mixing, and light input, shaping the Arctic ecosystem in unique ways not found in other regions of the world ocean. In 2016, we sampled a high-resolution grid of 135 hydrographic stations in Baffin Bay as part of the Green Edge project to study the ice-edge bloom, including turbulent vertical mixing, the under-ice light field, concentrations of inorganic nutrients, and phytoplankton biomass. We found pronounced differences between an Atlantic sector dominated by the warm West Greenland Current and an Arctic sector with surface waters originating from the Canadian archipelago. Winter overturning and thus nutrient replenishment was hampered by strong haline stratification in the Arctic domain, whereas close to the West Greenland shelf, weak stratification permitted winter mixing with high-nitrate Atlantic-derived waters. Using a space-for-time approach, we linked upper ocean dynamics to the phytoplankton bloom trailing the retreating ice edge. In a band of 60 km (or 15 days) around the ice edge, the upper ocean was especially affected by a freshened surface layer. Light climate, as evidenced by deep 0.415 mol m–2 d–1 isolumes, and vertical mixing, as quantified by shallow mixing layer depths, should have permitted significant net phytoplankton growth more than 100 km into the pack ice at ice concentrations close to 100%. Yet, under-ice biomass was relatively low at 20 mg chlorophyll-a m–2 and depth-integrated total chlorophyll-a (0–80 m) peaked at an average value of 75 mg chlorophyll-a m–2 only around 10 days after ice retreat. This phenological peak may hence have been the delayed result of much earlier bloom initiation and demonstrates the importance of temporal dynamics for constraints of Arctic marine primary production. |
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8123 |
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L. C. Matthes, J. K. Ehn, S. L.-Girard, N. M. Pogorzelec, M. Babin, C. J. Mundy |
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Title |
Average cosine coefficient and spectral distribution of the light field under sea ice: Implications for primary production |
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Journal |
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Year |
2019 |
Publication |
Elementa: Science of the Anthropocene |
Abbreviated Journal |
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Volume |
7 |
Issue |
25 |
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The Arctic spring phytoplankton bloom has been reported to commence under a melting sea ice cover as transmission of photosynthetically active radiation (PAR; 400–700 nm) suddenly increases with the formation of surface melt ponds. Spatial variability in ice surface characteristics, i.e., snow thickness or melt pond distributions, and subsequent impact on transmitted PAR makes estimating light-limited primary production difficult during this time of year. Added to this difficulty is the interpretation of data from various sensor types, including hyperspectral, multispectral, and PAR-band irradiance sensors, with either cosine-corrected (planar) or spherical (scalar) sensor heads. To quantify the impact of the heterogeneous radiation field under sea ice, spectral irradiance profiles were collected beneath landfast sea ice during the Green Edge ice-camp campaigns in May–June 2015 and June–July 2016. Differences between PAR measurements are described using the downwelling average cosine, μd, a measure of the degree of anisotropy of the downwelling underwater radiation field which, in practice, can be used to convert between downwelling scalar, E0d, and planar, Ed, irradiance. A significantly smallerμd(PAR) was measured prior to snow melt compared to after (0.6 vs. 0.7) when melt ponds covered the ice surface. The impact of the average cosine on primary production estimates, shown in the calculation of depth-integrated daily production, was 16% larger under light-limiting conditions when E0d was used instead of Ed. Under light-saturating conditions, daily production was only 3% larger. Conversion of underwater irradiance data also plays a role in the ratio of total quanta to total energy (EQ/EW, found to be 4.25), which reflects the spectral shape of the under-ice light field. We use these observations to provide factors for converting irradiance measurements between irradiance detector types and units as a function of surface type and depth under sea ice, towards improving primary production estimates. |
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1164 |
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8124 |
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Margaux Gourdal, Odile Crabeck, Martine Lizotte, Virginie Galindo, Michel Gosselin, Marcel Babin, Michael Scarratt, Maurice Levasseur |
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Title |
Upward transport of bottom-ice dimethyl sulfide during advanced melting of arctic first-year sea ice |
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Year |
2019 |
Publication |
Elementa: Science of the Anthropocene |
Abbreviated Journal |
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Volume |
7 |
Issue |
33 |
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This paper presents the first empirical estimates of dimethyl sulfide (DMS) gas fluxes across permeable sea ice in the Arctic. DMS is known to act as a major potential source of aerosols that strongly influence the Earth’s radiative balance in remote marine regions during the ice-free season. Results from a sampling campaign, undertaken in 2015 between June 2 and June 28 in the ice-covered Western Baffin Bay, revealed the presence of high algal biomass in the bottom 0.1-m section of sea ice (21 to 380 µg Chl a L–1) combined with the presence of high DMS concentrations (212–840 nmol L–1). While ice algae acted as local sources of DMS in bottom sea ice, thermohaline changes within the brine network, from gravity drainage to vertical stabilization, exerted strong control on the distribution of DMS within the interior of the ice. We estimated both the mean DMS molecular diffusion coefficient in brine (5.2 × 10–5 cm2 s–1 ± 51% relative S.D., n = 10) and the mean bulk transport coefficient within sea ice (33 × 10–5 cm2 s–1 ± 41% relative S.D., n = 10). The estimated DMS fluxes ± S.D. from the bottom ice to the atmosphere ranged between 0.47 ± 0.08 µmol m–2 d–1 (n = 5, diffusion) and 0.40 ± 0.15 µmol m–2 d–1 (n = 5, bulk transport) during the vertically stable phase. These fluxes fall within the lower range of direct summer sea-to-air DMS fluxes reported in the Arctic. Our results indicate that upward transport of DMS, from the algal-rich bottom of first-year sea ice through the permeable sea ice, may represent an important pathway for this biogenic gas toward the atmosphere in ice-covered oceans in spring and summer. |
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2325-1026 |
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8126 |
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L. Oziel, P. Massicotte, A. Randelhoff, J. Ferland, A. Vladoiu, L. Lacour, V. Galindo, S. Lambert-Girard, D. Dumont, Y. Cuypers, P. Bouruet-Aubertot, C.-J. Mundy, J. Ehn, G. Bécu, C. Marec, M.-H. Forget, N. Garcia, P. Coupel, P. Raimbault, M.-N. Houssais, M. Babin |
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Title |
Environmental factors influencing the seasonal dynamics of spring algal blooms in and beneath sea ice in western Baffin Bay |
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Year |
2019 |
Publication |
Elementa: Science of the Anthropocene |
Abbreviated Journal |
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Volume |
7 |
Issue |
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Pages |
34 |
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Arctic sea ice is experiencing a shorter growth season and an earlier ice melt onset. The significance of spring microalgal blooms taking place prior to sea ice breakup is the subject of ongoing scientific debate. During the Green Edge project, unique time-series data were collected during two field campaigns held in spring 2015 and 2016, which documented for the first time the concomitant temporal evolution of the sea ice algal and phytoplankton blooms in and beneath the landfast sea ice in western Baffin Bay. Sea ice algal and phytoplankton blooms were negatively correlated and respectively reached 26 (6) and 152 (182) mg of chlorophyll a per m2 in 2015 (2016). Here, we describe and compare the seasonal evolutions of a wide variety of physical forcings, particularly key components of the atmosphere–snow–ice–ocean system, that influenced microalgal growth during both years. Ice algal growth was observed under low-light conditions before the snow melt period and was much higher in 2015 due to less snowfall. By increasing light availability and water column stratification, the snow melt onset marked the initiation of the phytoplankton bloom and, concomitantly, the termination of the ice algal bloom. This study therefore underlines the major role of snow on the seasonal dynamics of microalgae in western Baffin Bay. The under-ice water column was dominated by Arctic Waters. Just before the sea ice broke up, phytoplankton had consumed most of the nutrients in the surface layer. A subsurface chlorophyll maximum appeared and deepened, favored by spring tide-induced mixing, reaching the best compromise between light and nutrient availability. This deepening evidenced the importance of upper ocean tidal dynamics for shaping vertical development of the under-ice phytoplankton bloom, a major biological event along the western coast of Baffin Bay, which reached similar magnitude to the offshore ice-edge bloom. |
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2325-1026 |
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8127 |
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Rémi Amiraux, Lukas Smik, Denizcan Köseoğlu, Jean-François Rontani, Virginie Galindo, Pierre-Luc Grondin, Marcel Babin, Simon T. Belt |
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Title |
Temporal evolution of IP25 and other highly branched isoprenoid lipids in sea ice and the underlying water column during an Arctic melting season |
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Journal |
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Year |
2019 |
Publication |
Elementa: Science of the Anthropocene |
Abbreviated Journal |
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Volume |
7 |
Issue |
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Pages |
38 |
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In recent years, certain mono- and di-unsaturated highly branched isoprenoid (HBI) alkene biomarkers (i.e., IP25 and HBI IIa) have emerged as useful proxies for sea ice in the Arctic and Antarctic, respectively. Despite the relatively large number of sea ice reconstructions based on IP25 and HBI IIa, considerably fewer studies have addressed HBI variability in sea ice or in the underlying water column during a spring bloom and ice melt season. In this study, we quantified IP25 and various other HBIs at high temporal and vertical resolution in sea ice and the underlying water column (suspended and sinking particulate organic matter) during a spring bloom/ice melt event in Baffin Bay (Canadian Arctic) as part of the Green Edge project. The IP25 data are largely consistent with those reported from some previous studies, but also highlight: (i) the short-term variability in its production in sea ice; (ii) the release of ice algae with high sinking rates following a switch in sea ice conditions from hyper- to hyposaline within the study period; and (iii) the occurrence of an under-ice phytoplankton bloom. Outcomes from change-point analysis conducted on chlorophyll a and IP25, together with estimates of the percentage of ice algal organic carbon in the water column, also support some previous investigations. The co-occurrence of other di- and tri-unsaturated HBIs (including the pelagic biomarker HBI III) in sea ice are likely to have originated from the diatom Berkeleya rutilans and/or the Pleurosigma and Rhizosolenia genera, residing either within the sea ice matrix or on its underside. Although a possible sea ice source for HBIs such as HBI III may also impact the use of such HBIs as pelagic counterparts to IP25 in the phytoplankton marker-IP25 index, we suggest that the impact is likely to be small based on HBI distribution data. |
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1164 |
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ISSN |
2325-1026 |
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yes |
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8128 |
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| Permanent link to this record |
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Author |
Augustin Lafond, Karine Leblanc, Bernard Quéguiner, Brivaela Moriceau, Aude Leynaert, Véronique Cornet, Justine Legras, Joséphine Ras, Marie Parenteau, Nicole Garcia, Marcel Babin, Jean-Éric Tremblay |
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Title |
Late spring bloom development of pelagic diatoms in Baffin Bay |
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Journal |
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2019 |
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Elementa: science of the anthropocene |
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7 |
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44 |
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Abstract |
The Arctic Ocean is particularly affected by climate change, with changes in sea ice cover expected to impact phytoplankton primary production. During the Green Edge expedition, the development of the late spring–early summer diatom bloom was studied in relation with the sea ice retreat by multiple transects across the marginal ice zone. Biogenic silica concentrations and uptake rates were measured. In addition, diatom assemblage structures and their associated carbon biomass were determined, along with taxon-specific contributions to total biogenic silica production using the fluorescent dye PDMPO. Results indicate that a diatom bloom developed in open waters close to the ice edge, following the alleviation of light limitation, and extended 20–30 km underneath the ice pack. This actively growing diatom bloom (up to 0.19 μmol Si L–1 d–1) was associated with high biogenic silica concentrations (up to 2.15 μmol L–1), and was dominated by colonial fast-growing centric (Chaetoceros spp. and Thalassiosira spp.) and ribbon-forming pennate species (Fragilariopsis spp./Fossula arctica). The bloom remained concentrated over the shallow Greenland shelf and slope, in Atlantic-influenced waters, and weakened as it moved westwards toward ice-free Pacific-influenced waters. The development resulted in a near depletion of all nutrients eastwards of the bay, which probably induced the formation of resting spores of Melosira arctica. In contrast, under the ice pack, nutrients had not yet been consumed. Biogenic silica and uptake rates were still low (respectively <0.5 μmol L–1 and <0.05 μmol L–1 d–1), although elevated specific Si uptake rates (up to 0.23 d–1) probably reflected early stages of the bloom. These diatoms were dominated by pennate species (Pseudo-nitzschia spp., Ceratoneis closterium, and Fragilariopsis spp./Fossula arctica). This study can contribute to predictions of the future response of Arctic diatoms in the context of climate change. |
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1164 |
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2325-1026 |
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Approved |
yes |
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Call Number |
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Serial |
8132 |
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| Permanent link to this record |
