scholarly journals Environmental drivers of spring primary production in Hudson Bay

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
L. C. Matthes ◽  
J. K. Ehn ◽  
L. A. Dalman ◽  
D. G. Babb ◽  
I. Peeken ◽  
...  
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Inorganic Nitrogen ◽  
Late Spring ◽  
Environmental Drivers ◽  
Phytoplankton Production ◽  
Hudson Bay ◽  
Total Production ◽  
Mean Values ◽  
Light Levels

Pertinent environmental factors influencing the microalgal bloom during sea-ice breakup in Hudson Bay were investigated in June 2018, producing the first observations of late spring primary production in the offshore waters of this vast inland sea. Phytoplankton production was found to commence at the onset of ice melt, with surface nutrient depletion leading to the formation of a subsurface chlorophyll maximum in the open waters of western Hudson Bay. Concurrently, the melting mobile ice cover in central Hudson Bay created favorable conditions for a diatom-dominated under-ice bloom, with photosynthetic characteristics and relatively high production confirming that phytoplankton cells were able to acclimate to increasing light levels. Lower mean values of phytoplankton production and total chlorophyll a (TChl a) concentration observed under the sea ice (414 mg C m–2 d–1 and 33.7 mg TChl a m–2) than those observed in open waters during the late bloom stage in the western region (460 mg C m–2 d–1 and 53.5 mg TChl a m–2) were attributed to reduced under-ice light levels and low surface concentrations of dissolved inorganic nitrogen (<2 μmol L–1) in central Hudson Bay. However, the highly abundant subice diatom, Melosira arctica, was estimated to contribute an additional 378 mg C m–2 d–1 to under-ice production in this region. Therefore, this subice algal bloom appears to play a similar role in the seasonally ice-covered sub-Arctic as in the central Arctic Ocean where it contributes significantly to local production. By updating historical total production estimates of Hudson Bay ranging between 21.5 and 39 g C m–2 yr–1 with our late spring observations including the novel observation of M. arctica, annual production was recalculated to be 72 g C m–2 yr–1, which equates to mean values for interior Arctic shelves.

scholarly journals Satellite-measured seasonal variations in primary production in the scallop-farming region of the Okhotsk Sea

2009 ◽  
Vol 66 (7) ◽  
pp. 1557-1569 ◽  
Author(s):  
M. A. Mustapha ◽  
S. Sei-Ichi ◽  
T. Lihan
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Seasonal Variations ◽  
Cold Water ◽  
Late Spring ◽  
Frontal Area ◽  
Okhotsk Sea ◽  
Physical Processes ◽  
Soya Warm Current ◽  
Chl A

Abstract Mustapha, M. A., Sei-Ichi, S., and Lihan, T. 2009. Satellite-measured seasonal variations in primary production in the scallop-farming region of the Okhotsk Sea. – ICES Journal of Marine Science, 66: 1557–1569. Seasonal variation in primary production after a retreat of the sea ice in the scallop-farming region along the Hokkaido coast of the Okhotsk Sea (1998–2004) was determined using satellite images. Annual variability in primary production was caused by variability in the physical processes associated with retreat of the sea ice, advection of the Sōya Warm Current (SWC), and intrusion of the East Sakhalin Current (ESC). Variability in primary production resulted in variability in the Chl a concentration, which was also demonstrated with an empirical orthogonal function (EOF) analysis. Enhancement of Chl a concentration in the frontal area in late spring was demonstrated by the second EOF mode of Chl a concentration (14.2% of variance), in parallel with the generation of a well-developed frontal area resulting from the advection of warm waters of the SWC along the coast in late spring, as indicated by the second EOF mode of sea surface temperature (SST; 1.8% of variance). Elevated Chl a concentration and the presence of cold water of the ESC in late autumn were also highlighted by the third EOF mode of Chl a concentration (9.0% of variance) and SST (1.5% of variance). Prolonged high primary production within the scallop-farming region after spring is supported by the development of a frontal area in summer and strengthening of the ESC in autumn.

New and regenerated primary production in a productive reservoir ecosystem

2010 ◽  
Vol 67 (2) ◽  
pp. 278-287 ◽  
Author(s):  
Leah M. Domine ◽  
Michael J. Vanni ◽  
William H. Renwick
Keyword(s):  
Primary Production ◽  
Euphotic Zone ◽  
Gizzard Shad ◽  
Phytoplankton Production ◽  
Total Production ◽  
Relative Importance ◽  
Dorosoma Cepedianum ◽  
New Production ◽  
Total Primary Production ◽  
The Difference

The concept of new and regenerated production has been used extensively in marine ecosystems but rarely in freshwaters. We assessed the relative importance of new and regenerated phosphorus (P) in sustaining phytoplankton production in Acton Lake, a eutrophic reservoir located in southwestern Ohio, USA. Sources of nutrients to the euphotic zone, including watershed loading, fluxes from sediments, and excretion by sediment-feeding fish (gizzard shad, Dorosoma cepedianum ), were considered sources of new P input that support new primary production and were quantified over the course of a growing season. Regenerated production was estimated by the difference between new and total primary production. New production represented 32%–53% of total primary production, whereas regenerated production represented 47%–68% of total primary production. P excretion by gizzard shad supplied 45%–74% of new P and 24% of P required for total production. In summary, fluxes of P from the watershed and those from sediment-feeding fish need to be considered in strategies to reduce eutrophication in reservoir ecosystems.

scholarly journals Spatial distribution of epifaunal communities in the Hudson Bay system

Elem Sci Anth ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Marie Pierrejean ◽  
David G. Babb ◽  
Frédéric Maps ◽  
Christian Nozais ◽  
Philippe Archambault
Keyword(s):  
Surface Water ◽  
Organic Carbon ◽  
Primary Production ◽  
Particulate Organic Carbon ◽  
Environmental Drivers ◽  
Hudson Bay ◽  
Organic Carbon Content ◽  
Substrate Type ◽  
Annual Primary Production ◽  
Epibenthic Communities

The seasonal sea ice cover and the massive influx of river runoff into the Hudson Bay System (HBS) of the Canadian Arctic are critical factors influencing biological production and, ultimately, the dynamics and structure of benthic communities in the region. This study provides the most recent survey of epibenthic communities in Hudson Bay and Hudson Strait and explores their relationships with environmental variables, including mean annual primary production and particulate organic carbon in surface water, bottom oceanographic variables, and substrate type. Epibenthic trawl samples were collected at 46 stations, with a total of 380 epibenthic taxa identified, representing 71% of the estimated taxa within the system. Three communities were defined based on biomass and taxonomic composition. Ordination analyses showed them to be associated primarily with substrate type, salinity, and annual primary production. A first community, associated with coarse substrate, was distributed along the coastlines and near the river mouths. This community was characterized by the lowest density and taxonomic richness and the highest biomass of filter and suspension feeders. A second community, composed mostly of deposit feeders and small abundant epibenthic organisms, was associated with soft substrate and distributed in the deepest waters. A third community, associated with mixed substrate and mostly located near polynyas, was characterized by high diversity and biomass, with no clearly dominant taxon. The overall analysis indicated that bottom salinity and surface-water particulate organic carbon content were the main environmental drivers of these epibenthic community patterns. In the face of climate change, projections of increased river inflow and a longer open water season for the HBS could have major impacts on these epibenthic communities, emphasizing a need to continually improve our ability to evaluate and predict shifts in epibenthic richness and distribution.

scholarly journals The effects of nutrient additions on particulate and dissolved primary production and metabolic state in surface waters of three Mediterranean eddies

2011 ◽  
Vol 8 (9) ◽  
pp. 2595-2607 ◽  
Author(s):  
A. Lagaria ◽  
S. Psarra ◽  
D. Lefèvre ◽  
F. Van Wambeke ◽  
C. Courties ◽  
...  
Keyword(s):  
Primary Production ◽  
Surface Waters ◽  
Inorganic Nitrogen ◽  
Gross Primary Production ◽  
Community Respiration ◽  
Phytoplankton Production ◽  
Metabolic Rates ◽  
Nutrient Additions ◽  
Carbon Demand ◽  
Heterotrophic Prokaryotes

Abstract. We examined the effects of nutrient additions on rates of 14C-based particulate and dissolved primary production as well as O2-based metabolic rates in surface waters (8 m) of three anticyclonic eddies, located in the Western, Central and Eastern Mediterranean. Ship-board microcosm experiments employing additions of inorganic nitrogen (+N) and phosphorus (+P), alone and in combination (+NP), were conducted in June/July 2008 during the BOUM (Biogeochemistry from the Oligotrophic to the Ultra-oligotrophic Mediterranean) cruise. In all three experiments, particulate primary production was significantly stimulated by the additions of nitrogen (+N, +NP) while no effect was observed with the addition of phosphorus alone (+P). Percent extracellular release of photosynthate (PER) displayed the lowest values (4–8 %) in the +NP treatment. Among the three treatments (+N, +P, +NP), the +NP had the strongest effect on oxygen metabolic rates, leading to positive values of net community production (NCP > 0). These changes of NCP were mainly due to enhanced gross primary production (GPP) rather than reduced dark community respiration rates (DCR). In all three sites, in +NP treatment autotrophic production (whether expressed as GPP or PPtotal) was sufficient to fulfil the estimated carbon requirements of heterotrophic prokaryotes, while addition of nitrogen alone (+N) had a weaker effect on GPP, resulting in metabolically balanced systems. At the three sites, in treatments with N (+N, +NP), phytoplankton and heterotrophic prokaryote production were positively correlated. Heterotrophic conditions were observed in the Control and +P treatment at the central and eastern sites, and autotrophic production was not sufficient to supply estimated bacterial carbon demand, evidence of a decoupling of phytoplankton production and consumption by heterotrophic prokaryotes.

scholarly journals Under-Ice Phytoplankton Blooms: Shedding Light on the “Invisible” Part of Arctic Primary Production

2020 ◽  
Vol 7 ◽  
Author(s):  
Mathieu Ardyna ◽  
C. J. Mundy ◽  
Nicolas Mayot ◽  
Lisa C. Matthes ◽  
Laurent Oziel ◽  
...  
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Large Scale ◽  
Current Knowledge ◽  
Biogeochemical Cycles ◽  
The Arctic ◽  
Phytoplankton Production ◽  
Ice Melt ◽  
Phytoplankton Ecology ◽  
Environmental Setting

The growth of phytoplankton at high latitudes was generally thought to begin in open waters of the marginal ice zone once the highly reflective sea ice retreats in spring, solar elevation increases, and surface waters become stratified by the addition of sea-ice melt water. In fact, virtually all recent large-scale estimates of primary production in the Arctic Ocean (AO) assume that phytoplankton production in the water column under sea ice is negligible. However, over the past two decades, an emerging literature showing significant under-ice phytoplankton production on a pan-Arctic scale has challenged our paradigms of Arctic phytoplankton ecology and phenology. This evidence, which builds on previous, but scarce reports, requires the Arctic scientific community to change its perception of traditional AO phenology and urgently revise it. In particular, it is essential to better comprehend, on small and large scales, the changing and variable icescapes, the under-ice light field and biogeochemical cycles during the transition from sea-ice covered to ice-free Arctic waters. Here, we provide a baseline of our current knowledge of under-ice blooms (UIBs), by defining their ecology and their environmental setting, but also their regional peculiarities (in terms of occurrence, magnitude, and assemblages), which is shaped by a complex AO. To this end, a multidisciplinary approach, i.e., combining expeditions and modern autonomous technologies, satellite, and modeling analyses, has been used to provide an overview of this pan-Arctic phenological feature, which will become increasingly important in future marine Arctic biogeochemical cycles.

Physical Control of Phytoplankton Production under Sea Ice (Manitounuk Sound, Hudson Bay)

1981 ◽  
Vol 38 (11) ◽  
pp. 1385-1392 ◽  
Author(s):  
L. Legendre ◽  
R. G. Ingram ◽  
M. Poulin
Keyword(s):  
Surface Water ◽  
Sea Ice ◽  
Water Column ◽  
Phytoplankton Bloom ◽  
Phytoplankton Production ◽  
Hudson Bay ◽  
Ice Algae ◽  
Phytoplankton Blooms ◽  
Low Salinity ◽  
Light Utilization

In polar and subpolar seas, there are numerous accounts of phytoplankton blooms in the upper water column under the ice. Various mechanisms have been invoked to explain these blooms: the seeding of the underlying surface water by algal cells (epontic flora) released from the melting ice, the optimization of light utilization by the cells, and the stabilization of the upper water column by the low-salinity melting water. From studies conducted in Manitounuk Sound (Hudson Bay), it is proposed that phytoplankton blooms under the ice probably result from the simultaneous deepening of both the photic layer (seasonal light increase) and the stratified layer (low-salinity melting water). In ice-covered seas, the release of ice algae superimposes itself on the phytoplankton bloom, resulting in the observed algal increase under melting ice.Key words: phytoplankton, under-ice blooms, ice flora, stability, nutrients, Hudson Bay

scholarly journals Contribution of the deep chlorophyll maximum to primary production, phytoplankton assemblages and diversity in a small stratified lake

2020 ◽  
Author(s):  
Alexandrine Pannard ◽  
Dolors Planas ◽  
Philippe Le Noac’h ◽  
Myriam Bormans ◽  
Myriam Jourdain ◽  
...  
Keyword(s):  
Primary Production ◽  
Deep Layer ◽  
Light Attenuation ◽  
Environmental Drivers ◽  
Total Production ◽  
Deep Chlorophyll Maximum ◽  
Phytoplankton Assemblages ◽  
Stratified Lake ◽  
Stratified Lakes ◽  
Chlorophyll Maximum

Abstract This 6-month study characterized the contribution of deep chlorophyll maximum (DCM) to lake phytoplankton diversity and primary production, in relation to stratification during the ice-free season. Phytoplankton and zooplankton dynamics were examined with environmental drivers in a small stratified lake that presents vertical gradients of light and nutrients. The phytoplankton, first composed of diatoms and chrysophyceae, shifted to cyanobacteria in mid-July. With stratification increase, surface nutrient limitation appeared to favor motile species characteristic of oligotrophic environments above a deep layer of filamentous cyanobacteria, fueled by the vertical nutrient fluxes from sediment. The DCM contributed on average to 33% (but up to 60%) of total production during the strongest summer stratification period. In late summer, as stratification was eroding, the vertical gradient of nutrients was reduced, but light attenuation with depth increased. Distinct assemblages were identified between surface and deep layer with shade-adapted species. The contribution of DCM was reduced to 10%. Zooplankton community varied in conjunction with phytoplankton and stratification. Our study demonstrates no benefit of DCM for taxonomic and functional diversity and a limited contribution to total production. The depths over which phytoplankton use separate spatial niches may be lesser in a 6-m-deep lake compared with deeper stratified lakes.

scholarly journals Lingering Chukchi Sea sea ice and Chukchi Sea mean winds influence population age structure of euphausiids (krill) found in the bowhead whale feeding hotspot near Pt. Barrow, Alaska

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254418
Author(s):  
Carin J. Ashjian ◽  
Stephen R. Okkonen ◽  
Robert G. Campbell ◽  
Philip Alatalo
Keyword(s):  
Population Structure ◽  
Sea Ice ◽  
Interannual Variability ◽  
Chukchi Sea ◽  
Late Spring ◽  
Bowhead Whale ◽  
Environmental Drivers ◽  
Sea Ice Extent ◽  
Krill Abundance ◽  
Spring Sea Ice

Interannual variability in euphausiid (krill) abundance and population structure and associations of those measures with environmental drivers were investigated in an 11-year study conducted in late August–early September 2005–2015 in offshelf waters (bottom depth > 40 m) in Barrow Canyon and the Beaufort Sea just downstream of Distributed Biological Observatory site 5 (DBO5) near Pt. Barrow, Alaska. Statistically-significant positive correlations were observed among krill population structure (proportion of juveniles and adults), the volume of Late Season Melt Water (LMW), and late-spring Chukchi Sea sea ice extent. High proportions of juvenile and adult krill were seen in years with larger volumes of LMW and greater spring sea ice extents (2006, 2009, 2012–2014) while the converse, high proportions of furcilia, were seen in years with smaller volumes of LMW and lower spring sea ice extent (2005, 2007, 2010, 2011, 2015). These different life stage, sea ice and water mass regimes represent integrated advective responses to mean fall and/or spring Chukchi Sea winds, driven by prevailing atmospheric pressure distributions in the two sets of years. In years with high proportions of juveniles and adults, late-spring and preceding-fall winds were weak and variable while in years with high proportions of furcilia, late-spring and preceding-fall winds were strong, easterly and consistent. The interaction of krill life history with yearly differences in the northward transports of krill and water masses along with sea ice retreat determines the population structure of late-summer krill populations in the DBO5 region near Pt. Barrow. Years with higher proportions of mature krill may provide larger prey to the Pt. Barrow area bowhead whale prey hotspot. The characteristics of prey near Pt. Barrow is dependent on krill abundance and size, large-scale environmental forcing, and interannual variability in recruitment success of krill in the Bering Sea.

ENERGY TRANSFER EFFICIENCIES ON LOWER TROPHIC LEVELS WITH INTENSIVE OYSTER FARMING IN HIROSHIMA BAY, JAPAN

2017 ◽  
Author(s):  
Akira Umehara ◽  
Akira Umehara ◽  
Satoshi Asaoka ◽  
Satoshi Asaoka ◽  
Naoki Fujii ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Primary Production ◽  
Skeletonema Costatum ◽  
Warm Season ◽  
Nutrient Supply ◽  
Trophic Levels ◽  
Phytoplankton Primary Production ◽  
Mean Values ◽  
Hiroshima Prefecture ◽  
Study Species

In enclosed water areas, organic matters are actively produced by phytoplankton due to abundant nutrient supply from the rivers. In our study area of the semi-enclosed Hiroshima Bay, oyster farming consuming high primary production has been developed since the 1950s, and the oyster production of Hiroshima prefecture have had the largest market share (ca. 60%) in Japan. In this study, species composition of phytoplankton, primary production, and secondary production of net zooplanktons and oysters were determined seasonally at seven stations in the bay between November 2014 and August 2015. In the bay, diatoms including Skeletonema costatum dominated during the period of the study. The primary productions markedly increased during summer (August), and its mean values in the northern part of the bay (NB) and the southern part (SB) were 530 and 313 mgC/m2/d, respectively. The productions of net zooplankton and oyster increased during the warm season, and its mean values in the NB were 14 and 1.2 mgC/m2/d, and in SB were 28 and 0.9 mgC/m2/d, respectively. The energy transfer efficiencies from the primary producers to the secondary producers in the NB and SB were 2.8% and 9.1%, respectively. However, the transfer efficiency to the oysters was approximately 0.3% in the bay. This study clearly showed the spatial difference of the productions and transfer efficiencies, and the low contribution of the production of oysters in secondary productions in Hiroshima Bay.

scholarly journals Contrasting trends in sea ice and primary production in the Bering Sea and Arctic Ocean

2012 ◽  
Vol 69 (7) ◽  
pp. 1180-1193 ◽  
Author(s):  
Zachary W. Brown ◽  
Kevin R. Arrigo
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Arctic Ocean ◽  
Bering Sea ◽  
Net Primary Productivity ◽  
Remote Sensing Data ◽  
Ice Cover ◽  
The Arctic ◽  
Light Limitation ◽  
The Bering Sea

Abstract Brown, Z. W., and Arrigo, K. R. 2012. Contrasting trends in sea ice and primary production in the Bering Sea and Arctic Ocean. – ICES Journal of Marine Science, 69: . Satellite remote sensing data were used to examine recent trends in sea-ice cover and net primary productivity (NPP) in the Bering Sea and Arctic Ocean. In nearly all regions, diminished sea-ice cover significantly enhanced annual NPP, indicating that light-limitation predominates across the seasonally ice-covered waters of the northern hemisphere. However, long-term trends have not been uniform spatially. The seasonal ice pack of the Bering Sea has remained consistent over time, partially because of winter winds that have continued to carry frigid Arctic air southwards over the past six decades. Hence, apart from the “Arctic-like” Chirikov Basin (where sea-ice loss has driven a 30% increase in NPP), no secular trends are evident in Bering Sea NPP, which averaged 288 ± 26 Tg C year−1 over the satellite ocean colour record (1998–2009). Conversely, sea-ice cover in the Arctic Ocean has plummeted, extending the open-water growing season by 45 d in just 12 years, and promoting a 20% increase in NPP (range 441–585 Tg C year−1). Future sea-ice loss will likely stimulate additional NPP over the productive Bering Sea shelves, potentially reducing nutrient flux to the downstream western Arctic Ocean.

Sign in / Sign up

Export Citation Format

Share Document