|Nutrients in the North Sea, September 1988 to October 1989: use of nutrient ratios and nutrient/salinity relationships to identify sources and sinks of nutrients|
|Hydes, D.; Edmunds, H. (1992). Nutrients in the North Sea, September 1988 to October 1989: use of nutrient ratios and nutrient/salinity relationships to identify sources and sinks of nutrients. Sci. Total Environ. (Suppl.): 1149-1157|
|In: Science of the Total Environment. Elsevier: Amsterdam. ISSN 0048-9697, more|
Ammonia; Chemical oceanography; Nitrates; Nitrites; Nutrients; Nutrients (mineral); Phosphates; Salinity; Silicates; ANE, North Sea [gazetteer]; Marine
Each month, measurements of ammonia, nitrate, nitrite, phosphate and silicate were made on a 120 station grid between 55° 30'N and the Dover Straights. Absolute concentrations were highest in the German Bight, corresponding to the low salinity of the water. The quality of the data is such that mapping the residuals from a linear regression fit to the nutrient salinity relationship shows coherent patterns that can be related to the different concentrations of nutrients in the individual rivers entering the North Sea. The Redfield ratio is only a poor approximation of the relationship between nitrate and phosphate, even in winter months. In January, in coastal areas the ratio is above 20 due to the high value in river water, while in the southern central area it is below 10.