Spatial variability in rates of net primary production (NPP) and onset of the spring bloom in Greenland shelf waters

doi:10.1016/j.pocean.2021.102655

Progress in Oceanography

Volume 198, November 2021, 102655

https://doi.org/10.1016/j.pocean.2021.102655 Get rights and content

Highlights

•
Rates of annual NPP show a strong south-north gradient, with higher NPP rates observed in the North Atlantic water-influenced southern regions, with up to a factor of 3 decrease in NPP towards the north, in the western Eurasian Basin of the Arctic Ocean.
•
Bloom initiation shows a strong south-north gradient, beginning in April in the southern regions and late June in the Arctic Ocean.
•
An average 55% to 75% of the annual production can be exported to depth, higher in Arctic and sub-Arctic regions, suggesting Greenland shelf waters have a potential for high carbon export to depth.

Abstract

Greenland extends from 60° to 83° N, with 80% of its land mass covered by the Greenland Ice Sheet (GrIS). This extensive latitudinal gradient is associated with concomitant environmental gradients that impact the biogeochemical properties of its coastal waters. Although the Greenland fjords have been the subject of intense study, less is known of the productivity in the continental shelves, regions that support local fisheries and influence fjord oceanography. This study provides a large-scale overview of annual net primary production rates (NPP) and their spatial variability in 7 regional shelves around Greenland, over the last decade (2008–2017), with special emphasis on spring bloom initiation. NPP is estimated by two independent approaches already established as best for estimating Arctic productivity: a physically-biologically coupled, regional 3D ocean model (SINMOD) and a spectrally-resolved, light-photosynthesis model of primary production (UQUAR-Takuvik model) that is applied to satellite observations of phytoplankton chlorophyll a, which is derived from ocean color remote sensing (OCRS). Both OCRS and SINMOD provide similar estimates of the timing and rates of productivity in Greenlandic waters, when compared with scarce field estimates. Bloom initiation shows a strong south-north gradient, beginning in April in the southern regions and late June in the Arctic Ocean. OCRS-modeled NPP highlights the effect of sea ice presence on bloom initiation; this method depicts the start of the bloom consistently later, by up to 13 days on average, than SINMOD-modeled NPP estimates. In contrast, numerical modeling is able to detect early phytoplankton growth in Greenland shelves, particularly underneath seasonal sea ice. Rates of annual NPP show a strong south-north gradient, with higher NPP rates observed in the North Atlantic water-influenced southern regions, with up to a factor of 3 decrease in NPP towards the north, in the western Eurasian Basin of the Arctic Ocean. Annual NPP varies from 78.3 ± 12.3 g C m⁻² yr⁻¹ and 80.3 ± 18.7 g C m⁻² yr⁻¹ in the southern regions to 24.7 ± 3.9 g C m⁻² yr⁻¹ in the Arctic Ocean. In each region, sea ice distribution and timing of formation and retreat affect location and timing of seasonal productivity with earlier and higher NPP offshore, moving inshore towards the summer. An average 55% to 75% of the annual production is estimated to be exported to depth, higher in Arctic and sub-Arctic regions, suggesting Greenland shelf waters have a potential for high carbon export to depth and relatively less carbon associated with the microbial food web.

Graphical abstract

Variability in the date of phytoplankton bloom initiation in Greenland continental shelf for the period 2008–2017. The bloom start date is estimated when the change in daily production exceeds 0.2 g C m⁻² d^-1. The shelves have been divided in 7 regions based on the Net Primary Production distribution in the coastal waters around Greenland: counter-clockwise, SouthEast (SE), Central East (CE), NorthEast (NE), North (N), NorthWest (NW), Central West (CW) and SouthWest (SW). Bloom initiation shows a strong north–south gradient, beginning in April in the southern regions (SE and SW) and in July in the Arctic Ocea (N). Sea ice presence (or lack thereof) appear to primarily determine the consistency in the timing of bloom initiation in each region.

Section snippets

Methods

NPP around Greenland waters was quantified with both a 3D, coupled hydrodynamic-ice-chemical-biological ocean numerical model system (SINMOD) and a light-photosynthesis model (Université du Québec à Rimouski (UQAR)-Takuvik) coupled with ocean color remote sensing observations (OCRS) for the period 2008–2017.

Spatial patterns of productivity

The SINMOD-based annually-integrated Net Primary Production (NPP_SINMOD) shows high rates in the open ocean south of Greenland, at 80–120 g C m⁻² yr⁻¹, decreasing northwards to 20–40 g C m⁻² yr⁻¹, with the exception of the north-eastern Greenland Sea with higher values of 60–80 g C m⁻² yr⁻¹ (Fig. 1b). A similar gradient is observed in the Greenland shelves, with decreasing productivity by a factor of 3–4 from south to north, with ~ 80 g C m⁻² yr⁻¹ in the SE and SW regions and a minimum of 25 g C

Discussion

The large latitudinal extent and associated pronounced change in temperature, daylength and sun angle correlate with variability in annual NPP, from 120 g C m⁻² yr⁻¹ in the Irminger and Labrador Seas to 40 g C m⁻² yr⁻¹ in the Arctic Ocean (Fig. 1). A sharp gradient in NPP is observed north of 75^oN, separating the influence of Atlantic waters to the south and Arctic waters to the north (Fig. 1). Overall, these constitute high rates of productivity for high-latitude plankton, similar to the

Conclusions

The purpose of this study was to establish the spatial variability in Net Primary Production (NPP) in Greenland shelf waters and the timing of bloom initiation. As the field data is too scarce to provide a reliable review on the subject, we used two numerical models, one of them based on ocean-color remote sensing, as first-order approaches to estimate NPP. The results from the models are directly compared to field estimates in order to generate new hypotheses of control factors and/or support

CRediT authorship contribution statement

Maria Vernet: Conceptualization, Investigation, Formal analysis, Writing – original draft, Writing – review & editing, Supervision. Ingrid Ellingsen: Conceptualization, Methodology, Software, Validation, Formal analysis, Data curation, Visualization. Christian Marchese: Data curation, Methodology, Software, Writing – review & editing, Visualization. Simon Bélanger: Methodology, Writing - review & editing. Mattias Cape: Writing – review & editing. Dag Slagstad: Conceptualization, Methodology.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

We would like to thank Matthieu Ardyna, Nicolas Mayot, Patrick Reimbault, and Michel Gosselin for making data available, to Thomas Jaegler for providing OCRS modeling data, B. Jack Pan for assistance with statistical analysis, and Søren Rysgaard for sharing missing literature. L. Meire kindly offered comments on an earlier version of the manuscript. The manuscript was greatly improved by comments from Markus Schartau and three anonymous reviewers. This project was funded by NASA award

References (208)

A. Alvera-Azcárate et al.
Reconstruction of incomplete oceanographic data sets using empirical orthogonal functions: Application to the Adriatic Sea surface temperature
Ocean Modelling
(2005)
K.R. Arrigo et al.
Continued increases in Arctic Ocean primary production
Progress in Oceanography
(2015)
M. Babin et al.
Estimation of primary production in the Arctic Ocean using ocean colour remote sensing and coupled physical–biological models: Strengths, limitations and how they compare
Progress in Oceanography
(2015)
D.G. Barber et al.
Selected physical, biological and biogeochemical implication of a rapidly changing Arctic margin ice zone
Progress in Oceanography
(2015)
S. Bélanger et al.
Impact of sea ice on the retrieval of water-leaving reflectance, chlorophyll a concentration and inherent optical properties from satellite ocean color data
Remote Sensing of Environment
(2007)
B. Bulgarelli et al.
On the detectability of adjacency effects in ocean color remote sensing of mid-latitude coastal environments by SeaWiFS, MODIS-A, MERIS, OLCI
OLI and MSI. Remote Sens Environ.
(2018)
L.A. Codispoti et al.
Synthesis of primary production in the Arctic Ocean: III. Nitrate and phosphate-based estimates of net community production
Progress in Oceanography
(2013)
J. Cuny et al.
Davis Strait volume, freshwater and heat fluxes
Deep Sea Research Part I: Oceanographic Research Papers
(2005)
R. Dickson et al.
Current estimates of freshwater flux through Arctic and subarctic seas
Progress in Oceanography
(2007)
G.M. Fragoso et al.
Biogeographical patterns and environmental controls of phytoplankton communities from contrasting hydrographical zones of the Labrador Sea
Progess in Oceanography
(2016)

E. Frajka-Williams et al.

Physical controls and mesoscale variability in the Labrador Sea spring phytoplankton bloom observed by Seaglider

Deep Sea Research Part I: Oceanographic Research Papers

(2009)

E. Frajka-Williams et al.

Physical controls and interannual variability of the Labrador Sea spring phytoplankton bloom in distinct regions

Deep Sea Research Part I: Oceanographic Research Papers

(2010)

P.S. Fratantoni et al.

Freshwater export from the Labrador Current to the North Atlantic Current at the Tail of the Grand Banks of Newfoundland

Deep Sea Research Part I: Oceanographic Research Papers

(2010)

H. Frigstad et al.

Variation in the seston C:N ratio of the Arctic Ocean and pan-Arctic shelves

Journal of Marine Systems

(2014)

C. Garside et al.

The f-ratio on 20°W during the North Atlantic Bloom Experiment

Deep Sea Research II

(1993)

T.W.N. Haine et al.

Arctic freshwater export: Status, mechanisms, and prospects

Global and Planetary Change

(2015)

S.A. Henson et al.

Effect of meteorological conditions on interannual variability in timing and magnitude of the spring bloom in the Irminger Basin, North Atlantic

Deep Sea Research, Part A

(2006)

V.J. Hill et al.

Synthesis of integrated primary production in the Arctic Ocean: II. In situ and remotely sensed estimates

Progress in Oceanography

(2013)

N.P. Holliday et al.

Large-scale physical controls on phytoplankton growth in the Irminger Sea Part I: Hydrographic zones, mixing and stratification

Journal of Marine Systems

(2006)

R.G. Ingram et al.

An overview of physical processes in the North Water

Deep Sea Research Part II

(2002)

T. Kawasaki et al.

Effect of freshwater from the West Greenland Current on the winter deep convection in the Labrador Sea

Ocean Modelling

(2014)

B. Klein et al.

Phytoplankton biomass, production and potential export in the North Water

Deep Sea Research Part II: Topical Studies in Oceanography

(2002)

A. Alvera-Azcárate et al.

Multivariate reconstruction of missing data in sea surface temperature, chlorophyll, and wind satellite fields

Journal of Geophysical Research: Oceans

(2007)

A. Alvera-Azcárate et al.

Data interpolating empirical orthogonal functions (DINEOF): A tool for geophysical data analyses

Mediterranean Marine Science

(2011)

M. Ardyna et al.

Recent Arctic Ocean sea ice loss triggers novel fall phytoplankton blooms

Geophysical Research Letters

(2014)

M. Ardyna et al.

Environmental drivers of under-ice phytoplankton bloom dynamics in the Arctic Ocean

Elementa: Science of the Anthropocene

(2020)

M. Ardyna et al.

'Under-ice phytoplankton blooms: Shedding light on the “invisible” part of Arctic primary production

Frontiers in Marine Science

(2020)

K.R. Arrigo et al.

Primary production in Southern Ocean waters

Journal of Geophysical Research: Oceans

(1998)

K.R. Arrigo et al.

Primary productivity in the Arctic Ocean: Impacts of complex optical properties and subsurface chlorophyll maxima on large-scale estimates

Journal of Geophysical Research: Oceans

(2011)

K.R. Arrigo et al.

Melting glaciers stimulate large summer phytoplankton blooms in southwest Greenland waters

Geophysical Research Letters

(2017)

A. Aschwanden et al.

Contribution of the Greenland Ice Sheet to sea level over the next millennium

Science advances

(2019)

J. Bamber et al.

Recent large increases in freshwater fluxes from Greenland into the North Atlantic

Geophysical Research Letters

(2012)

J.L. Bamber et al.

Land ice freshwater budget of the Arctic and North Atlantic Oceans: 1. Data, methods, and results

Journal of Geophysical Research: Oceans

(2018)

S. Bélanger et al.

Increasing cloudiness in Arctic damps the increase in phytoplankton primary production due to sea ice receding

Biogeosciences

(2013)

S. Beldring et al.

Estimation of parameters in a distributed precipitation-runoff model for Norway

Hydrology and Earth System Sciences

(2003)

M. Bergeron et al.

Shifts in biological productivity inferred from nutrient drawdown in the southern Beaufort Sea (2003–2011) and northern Baffin Bay (1997–2011)

Canadian Arctic. Geophysical Research Letters

(2014)

Bi, H., Zhang, Z., Wang, Y., Xu, X., Liang, Y., Huang, J., Liu, Y., Fu, M., 2019. Baffin Bay sea ice inflow and...

T.C. Biló et al.

Interior pathways of Labrador Sea Water in the North Atlantic from the Argo perspective

Geophysical Research Letters

(2019)

Bindoff, N. L., Cheung, W. L., Kairo, J. G., Arístegui, J., Guinder, V. A., Hallberg, R., et al., 2019. Changing ocean,...

M. Blais et al.

Contrasting interannual changes in phytoplankton productivity and community structure in the coastal Canadian Arctic Ocean

Limnology and Oceanography

(2017)

L. Bopp et al.

Multiple stressors of ocean ecosystems in the 21st century: Projections with CMIP5 models

Biogeosciences

(2013)

R.H. Bourke et al.

Oceanography of Nares Strait and northern Baffin Bay in 1986 with emphasis on deep and bottom water formation

Journal of Geophysical Research: Oceans

(1989)

J.E. Box

Survey of Greenland instrumental temperature records: 1873–2001

International Journal of Climatology: a Journal of the Royal Meteorological Society

(2002)

Boyer, T.P., Baranova, O.K., Biddle, M., Johnson, D.R., Mishonov, A.V., Paver, C., Seidov, D., Zweng, M., 2012. Arctic...

T.P. Boyer et al.

World Ocean Atlas 2018

(2018)

J.F. Bromaghin et al.

Polar bear population dynamics in the southern Beaufort Sea during a period of sea ice decline

Ecological Applications

(2015)

E. Buch

A monograph on the Physical Oceanography of the Greenland Waters. Greenland Fisheries Research Institute Report, (reissued in 2000 as Danish Meteorological Institute

Scientific report

(1990/2000)

E. Buch

Present oceanographic conditions in Greenland waters

(2002)

E. Buch

Physical oceanography of the Greenland Sea

Wollaston Forland

(2007)

A. Bursa

Phytoplankton in coastal waters of the Arctic Ocean at Point Barrow, Alaska

Arctic

(1963)

Cited by (16)

Assessing net primary production in the northwestern Barents Sea using in situ, remote sensing and modelling approaches
2023, Progress in Oceanography
The northwestern Barents Sea (NW-BS) is a highly productive region within the transitional zones of an Atlantic to Arctic-dominated marine ecosystem. The steep latitudinal gradients in sea ice concentration, Atlantic and Arctic Water, offer an opportunity to test hypotheses on physical drivers of spatial and temporal variability of net primary production (NPP). However, quantifying NPP in such a large ocean region can be challenged by the lack of in situ measurements with high spatial and temporal resolution, and gaps in remote sensing estimates due to the presence of clouds and sea ice, and assumptions regarding the depth distribution of alga biomass. Without reliable data to evaluate models, filling these gaps with numerical models is limited by the model representation of the physical environment and its assumptions about the relationships between NPP and its main limiting factors. Hence, within the framework of the Nansen Legacy Project, we combined in situ measurements, remote sensing, and model simulations to constrain the estimates of phytoplankton NPP in the NW-BS. The region was subdivided into Atlantic, Subarctic, and Arctic subregions on the basis of different phytoplankton phenology. In 2004 there was a significant regime change in the Atlantic subregion that resulted in a step-increase in NPP in tandem with a step-decrease in sea ice concentration. Contrary to results from other Arctic seas, this study does not find any long term trends in NPP despite changes in the physical environment. Mixing was the main driver of simulated annual NPP in the Atlantic subregion, while light and nutrients drove annual NPP in the Subarctic and Arctic subregions. The multi-source estimate of annual NPP ranged 79–118 gC m⁻² yr⁻¹ in the Atlantic, 74–82 gC m⁻² yr⁻¹ in the Subarctic, and 19–47 gC m⁻² yr⁻¹ in the Arctic. The total NPP in the NW-BS region was estimated between 15 and 48 Tg C yr⁻¹, which is 15–50% of the total NPP needed to sustain three of the most harvested fish species north of 62°N (roughly 90 Tg C yr⁻¹). This research shows the importance of continuing to strive for better regional estimates of NPP.
Coastal freshening drives acidification state in Greenland fjords
2023, Science of the Total Environment
Citation Excerpt :
Concurrent elevated AOU in deeper water (>40 m on the West Coast) indicates there is a greater bacterial oxygen utilization, resulting in the buildup of CO2 that causes the observed lower aragonite saturation state. Model and satellite ocean color observations show higher productivity on the western coast of Greenland in our study area (west: 49.5 ± 13.89 vs. east: 23.6 ± 7.12 g C m−2 yr−1) (Vernet et al., 2021). Within our study, western coast photic zone oxygen production appears to support these findings (Fig. 3a).
Greenland's fjords and coastal waters are highly productive and sustain important fisheries. However, retreating glaciers and increasing meltwater are changing fjord circulation and biogeochemistry, which may threaten future productivity. The freshening of Greenland fjords caused by unprecedented melting of the Greenland Ice Sheet may alter carbonate chemistry in coastal waters, influencing CO₂ uptake and causing biological consequences from acidification. However, few studies to date explore the current acidification state in Greenland coastal waters. Here we present the first-ever large-scale measurements of carbonate system parameters in 16 Greenlandic fjords and seek to identify the drivers of acidification state in these freshening ecosystems. Aragonite saturation state (Ω), a proxy for ocean acidification, was calculated from dissolved inorganic carbon (DIC) and total alkalinity from fjords along the east and west coast of Greenland spanning 68–75°N. Aragonite saturation was primarily >1 in the surface mixed layer. However, undersaturated—or corrosive––conditions (Ω < 1) were observed on both coasts (west: Ω = 0.28–3.11, east: Ω = 0.70–3.07), albeit at different depths. West Greenland fjords were largely corrosive at depth while undersaturation in East Greenland fjords was only observed in surface waters. This reflects a difference in the coastal boundary conditions and mechanisms driving acidification state. We suggest that advection of Sub Polar Mode Water and accumulation of DIC from organic matter decomposition drive corrosive conditions in the West, while freshwater alkalinity dilution drives acidification in the East. The presence of marine terminating glaciers also impacted local acidification states by influencing fjord circulation: upwelling driven by subglacial discharge brought corrosive bottom waters to shallower depths. Meanwhile, discharge from land terminating glaciers strengthened stratification and diluted alkalinity. Regardless of the drivers in each system, increasing freshwater discharge will likely lower carbonate saturation states and impact biotic and abiotic carbon uptake in the future.
An Ecological Quality Evaluation of Large-Scale Farms Based on an Improved Remote Sensing Ecological Index
2024, Remote Sensing
Analysis of Spatiotemporal Evolution and Influencing Factors of Vegetation Net Primary Productivity in the Yellow River Basin from 2000 to 2022
2024, Sustainability (Switzerland)
Temporal and Spatial Characteristics of Soil Salinization and Its Impact on Cultivated Land Productivity in the BOHAI Rim Region
2023, Water (Switzerland)
The sensitivity of primary productivity in Disko Bay, a coastal Arctic ecosystem, to changes in freshwater discharge and sea ice cover
2023, Ocean Science

View all citing articles on Scopus

View full text

Spatial variability in rates of net primary production (NPP) and onset of the spring bloom in Greenland shelf waters

Highlights

Abstract

Graphical abstract

Section snippets

Methods

Spatial patterns of productivity

Discussion

Conclusions

CRediT authorship contribution statement

Declaration of Competing Interest

Acknowledgements

Ocean Modelling

Progress in Oceanography

Progress in Oceanography

Progress in Oceanography

Remote Sensing of Environment

OLI and MSI. Remote Sens Environ.

Progress in Oceanography

Deep Sea Research Part I: Oceanographic Research Papers

Progress in Oceanography

Progess in Oceanography

Deep Sea Research Part I: Oceanographic Research Papers

Deep Sea Research Part I: Oceanographic Research Papers

Deep Sea Research Part I: Oceanographic Research Papers

Journal of Marine Systems

Deep Sea Research II

Global and Planetary Change

Deep Sea Research, Part A

Progress in Oceanography

Journal of Marine Systems

Deep Sea Research Part II

Ocean Modelling

Deep Sea Research Part II: Topical Studies in Oceanography

Multivariate reconstruction of missing data in sea surface temperature, chlorophyll, and wind satellite fields

Journal of Geophysical Research: Oceans

Data interpolating empirical orthogonal functions (DINEOF): A tool for geophysical data analyses

Mediterranean Marine Science

Recent Arctic Ocean sea ice loss triggers novel fall phytoplankton blooms

Geophysical Research Letters

Environmental drivers of under-ice phytoplankton bloom dynamics in the Arctic Ocean

Elementa: Science of the Anthropocene

'Under-ice phytoplankton blooms: Shedding light on the “invisible” part of Arctic primary production

Frontiers in Marine Science

Primary production in Southern Ocean waters

Journal of Geophysical Research: Oceans

Primary productivity in the Arctic Ocean: Impacts of complex optical properties and subsurface chlorophyll maxima on large-scale estimates

Journal of Geophysical Research: Oceans

Melting glaciers stimulate large summer phytoplankton blooms in southwest Greenland waters

Geophysical Research Letters

Contribution of the Greenland Ice Sheet to sea level over the next millennium

Science advances

Recent large increases in freshwater fluxes from Greenland into the North Atlantic

Geophysical Research Letters

Land ice freshwater budget of the Arctic and North Atlantic Oceans: 1. Data, methods, and results

Journal of Geophysical Research: Oceans

Increasing cloudiness in Arctic damps the increase in phytoplankton primary production due to sea ice receding

Biogeosciences

Estimation of parameters in a distributed precipitation-runoff model for Norway

Hydrology and Earth System Sciences

Shifts in biological productivity inferred from nutrient drawdown in the southern Beaufort Sea (2003–2011) and northern Baffin Bay (1997–2011)

Canadian Arctic. Geophysical Research Letters

Interior pathways of Labrador Sea Water in the North Atlantic from the Argo perspective

Geophysical Research Letters

Contrasting interannual changes in phytoplankton productivity and community structure in the coastal Canadian Arctic Ocean

Limnology and Oceanography

Multiple stressors of ocean ecosystems in the 21st century: Projections with CMIP5 models

Biogeosciences

Oceanography of Nares Strait and northern Baffin Bay in 1986 with emphasis on deep and bottom water formation

Journal of Geophysical Research: Oceans

Survey of Greenland instrumental temperature records: 1873–2001

International Journal of Climatology: a Journal of the Royal Meteorological Society

World Ocean Atlas 2018

Polar bear population dynamics in the southern Beaufort Sea during a period of sea ice decline

Ecological Applications

A monograph on the Physical Oceanography of the Greenland Waters. Greenland Fisheries Research Institute Report, (reissued in 2000 as Danish Meteorological Institute

Scientific report

Present oceanographic conditions in Greenland waters

Physical oceanography of the Greenland Sea

Wollaston Forland