The influence of Arctic Fe and Atlantic fixed N on summertime primary production in Fram Strait, North Greenland Sea


Contact
Martin.Graeve [ at ] awi.de

Abstract

Climate change has led to a ~ 40% reduction in summer Arctic sea-ice cover extent since the 1970s. Resultant increases in light availability may enhance phytoplankton production. Direct evidence for factors currently constraining summertime phytoplankton growth in the Arctic region is however lacking. GEOTRACES cruise GN05 conducted a Fram Strait transect from Svalbard to the NE Greenland Shelf in summer 2016, sampling for bioessential trace metals (Fe, Co, Zn, Mn) and macronutrients (N, Si, P) at ~ 79°N. Five bioassay experiments were conducted to establish phytoplankton responses to additions of Fe, N, Fe + N and volcanic dust. Ambient nutrient concentrations suggested N and Fe were deficient in surface seawater relative to typical phytoplankton requirements. A west-to-east trend in the relative deficiency of N and Fe was apparent, with N becoming more deficient towards Greenland and Fe more deficient towards Svalbard. This aligned with phytoplankton responses in bioassay experiments, which showed greatest chlorophyll-a increases in + N treatment near Greenland and + N + Fe near Svalbard. Collectively these results suggest primary N limitation of phytoplankton growth throughout the study region, with conditions potentially approaching secondary Fe limitation in the eastern Fram Strait. We suggest that the supply of Atlantic-derived N and Arctic-derived Fe exerts a strong control on summertime nutrient stoichiometry and resultant limitation patterns across the Fram Strait region.



Item Type
Article
Authors
Divisions
Primary Division
Programs
Primary Topic
Publication Status
Published
Eprint ID
53037
DOI 10.1038/s41598-020-72100-9

Cite as
Krisch, S. , Browning, T. J. , Graeve, M. , Ludwichowski, K. U. , Lodeiro, P. , Hopwood, M. J. , Roig, S. , Yong, J. C. , Kanzow, T. and Achterberg, E. P. (2020): The influence of Arctic Fe and Atlantic fixed N on summertime primary production in Fram Strait, North Greenland Sea , Scientific Reports, 10 (1) . doi: 10.1038/s41598-020-72100-9


Download
[thumbnail of s41598-020-72100-9.pdf]
Preview
PDF
s41598-020-72100-9.pdf

Download (6MB) | Preview

Share
Add to AnyAdd to TwitterAdd to FacebookAdd to LinkedinAdd to PinterestAdd to Email


Citation

Geographical region

Research Platforms

Campaigns
N/A


Actions
Edit Item Edit Item