NUTRIENTS (P, N, SI) IN THE CHANNEL AND THE DOVER STRAIT - SEASONAL AND YEAR-TO-YEAR VARIATION AND FLUXES TO THE NORTH-SEA

Citation
Rwpm. Laane et al., NUTRIENTS (P, N, SI) IN THE CHANNEL AND THE DOVER STRAIT - SEASONAL AND YEAR-TO-YEAR VARIATION AND FLUXES TO THE NORTH-SEA, Oceanologica acta, 16(5-6), 1993, pp. 607-616
Citations number
51
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Oceanografhy
Journal title
ISSN journal
0399-1784
Volume
16
Issue
5-6
Year of publication
1993
Pages
607 - 616
Database
ISI
SICI code
0399-1784(1993)16:5-6<607:N(NSIT>2.0.ZU;2-7
Abstract
Recent measurements (1986-1988) of the distribution of the concentrati on of different nutrients (nitrogen, phosphorus and silicate) in the D over Strait have been used, combined with older results, to calculate the total flux (dissolved and particulate) of nutrients into the North Sea. Special efforts are made to take into account in the fluxes the tidal, geographical and temporal variations in the concentrations of t he different nutrients. No vertical gradients in the concentration of the different nutrients were found. Increased nutrient concentration w as found in the coastal zones of England and France, compared to the A tlantic water in the central part of the Dover Strait The variation wi thin a single year and between different years in the data available ( 1930-1988) for the different nutrients was rather large and no clear, annual trends could be distinguished. Average yearly fluxes are, for a mmonium, nitrate, nitrite and total nitrogen respectively: 156 +/-29, 364 +/- 68, 26 +/- 6 and 1411 +/- 209 ktonnes N; for ortho-phosphate a nd total phosphorus, 79 +/- 13 and 192 +/- 32 ktonnes P per year and f or dissolved silicate 492 +/- 80 ktonnes Si per year. These fluxes are higher than those published before, because in this study the particu late fraction and the dissolved organic fraction of the nutrients (exc ept Si) are also taken into account.