Simultaneous assessment of oxygen- and nitrate-based net community production in a temperate shelf sea from a single ocean glider

Hull, Tom; Greenwood, Naomi; Birchill, Antony; Beaton, Alexander; Palmer, Matthew; Kaiser, Jan. 2021 Simultaneous assessment of oxygen- and nitrate-based net community production in a temperate shelf sea from a single ocean glider. Biogeosciences, 18 (23). 6167-6180. 10.5194/bg-18-6167-2021

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Official URL: http://dx.doi.org/10.5194/bg-18-6167-2021

Abstract/Summary

The continental shelf seas are important at a global scale for ecosystem services. These highly dynamic regions are under a wide range of stresses, and as such future management requires appropriate monitoring measures. A key metric to understanding and predicting future change are the rates of biological production. We present here the use of an autonomous underwater glider with an oxygen (O2) and a wet-chemical microfluidic total oxidised nitrogen (NOx−=NO3−+NO2−) sensor during a spring bloom as part of a 2019 pilot autonomous shelf sea monitoring study. We find exceptionally high rates of net community production using both O2 and NOx− water column inventory changes, corrected for air–sea gas exchange in case of O2. We compare these rates with 2007 and 2008 mooring observations finding similar rates of NOx− consumption. With these complementary methods we determine the O2:N amount ratio of the newly produced organic matter (7.8 ± 0.4) and the overall O2:N ratio for the total water column (5.7 ± 0.4). The former is close to the canonical Redfield O2:N ratio of 8.6 ± 1.0, whereas the latter may be explained by a combination of new organic matter production and preferential remineralisation of more reduced organic matter at a higher O2:N ratio below the euphotic zone.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.5194/bg-18-6167-2021
ISSN:	1726-4189
Date made live:	11 Jan 2022 14:37 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/531739

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.5194/bg-18-6167-2021

ISSN:

1726-4189

Date made live:

11 Jan 2022 14:37 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/531739