The University of Southampton
University of Southampton Institutional Repository

Low nitrate: phosphate ratios in the global ocean

Tyrrell, T. and Law, C.S. (1997) Low nitrate: phosphate ratios in the global ocean Nature, 387, (6635), pp. 793-796.

Record type: Article


The distribution and availability of the nutrients nitrate and phosphate exert a strong control over primary production in the world ocean. Here we use a recently compiled global data set of oceanographic observations—a database that is at least 40 times larger than currently used data sets (for example, ref. 2)—to analyse the variation of the nitrate:phosphate concentration ratio with depth and geographical location. Although the nutrient distributions confirm the dominant influence of aerobic decomposition, in agreement with the observations of Redfield, we also identify a hitherto unreported secondary trend at low nitrate: phosphate ratio (2–3). These conditions of low nitrate:phosphate ratio are associated with low oxygen concentrations and are probably caused by denitrification. Examination of the geographical distribution of these low nitrate:phosphate data suggests that denitrification in the western and northern North Pacific Ocean may have been previously overlooked, and that a reassessment of the global oceanic denitrification budget may therefore be required.

Full text not available from this repository.

More information

Published date: 19 June 1997


Local EPrints ID: 50822
ISSN: 0028-0836
PURE UUID: e937d89a-0247-472d-a968-fa120d67ff51
ORCID for T. Tyrrell: ORCID iD

Catalogue record

Date deposited: 02 Apr 2008
Last modified: 17 Jul 2017 14:50

Export record


Author: T. Tyrrell ORCID iD
Author: C.S. Law

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 supports OAI 2.0 with a base URL of

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.