The University of Southampton
University of Southampton Institutional Repository

Nutrients and chlorophyll at two sites in the Thames plume and southern North Sea

Record type: Article

The Thames plume is a moderately turbid (suspended load up to 80 mg dm?3), high nutrient (summer NO3? concentrations >10 M, summer PO43? concentrations >2.5 M) and well-mixed aquatic ecosystem which connects the Thames estuary to the southern North Sea. Six cruises were undertaken to investigate the response of an inshore site in this system to these high nutrient levels via a comparison with a site in the seasonally nutrient-depleted southern North Sea. The seasonal cycle of chlorophyll concentrations in both environments was similar, consisting of higher chlorophyll a levels in spring than in summer. A spring bloom of diatoms occurs in both environments; in the plume it is succeeded by low chlorophyll levels and a diatom-dominated community at low silicate levels and at the offshore site by a non-siliceous community at similar silicate levels. The low summer chlorophyll levels and diatom dominance, which occur at the inshore site despite an abundance of nitrate and phosphate may be due to a simultaneous inhibition of non-siliceous growth and silicate limitation of diatom growth. We hypothesise that this is caused by the high turbidity at the inshore site reducing water column light levels such that they become adequate for diatom growth but inadequate for non-siliceous growth; however, we have inadequate data to confirm this suggestion. The benthic silicate flux cannot support the inferred diatom silicate requirement at the inshore site suggesting that silicate mineralisation in the water column may occur and control diatom growth. Nutrient/salinity plots suggest that the net effect of this complex biogeochemistry is a semi-conservative transport of NO3? and PO43? through the plume to the offshore region.

Full text not available from this repository.

Citation

Sanders, R., Jickells, T. and Mills, D. (2001) Nutrients and chlorophyll at two sites in the Thames plume and southern North Sea Journal of Sea Research, 46, (1), pp. 13-28. (doi:10.1016/S1385-1101(01)00068-5).

More information

Published date: 2001
Keywords: NUTRIENTS, THAMES PLUME, ESTUARIES, PHYTOPLANKTON, CHLOROPHYLL, SILICATE, PHOSPHATE, SOUTHERN NORTH SEA

Identifiers

Local EPrints ID: 7939
URI: http://eprints.soton.ac.uk/id/eprint/7939
ISSN: 1385-1101
PURE UUID: d00c33d4-fc60-4cdf-b1cd-0cb8d5aab526

Catalogue record

Date deposited: 10 Aug 2004
Last modified: 17 Jul 2017 17:13

Export record

Altmetrics

Contributors

Author: R. Sanders
Author: T. Jickells
Author: D. Mills

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×