Suess, Erwin (1976) Nutrients Near the Depositional Interface. In: The Benthic Boundary Layer. , ed. by McCave, I. N.. Plenum Publishing Corporation, New York, pp. 57-79. ISBN 978-1-4615-8749-1 DOI 10.1007/978-1-4615-8747-7_4.

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Abstract

The regeneration of nutrients in the benthic boundary layer is discussed with examples from a stagnant basin of the Baltic Sea, from the continental slope off West Africa, and from deep oceanic sediments of the Central Pacific. Under stagnant conditions in fiord waters and sediments more phosphate and less ammonia are regenerated than would be predicted from chemical decomposition models, but total carbon dioxide and hydrogen sulfide are found in the expected amounts. The excess of dissolved phosphate is related to dissolution of inorganic iron-manganese-phosphate precipitates and the deficit in ammonia is thought to reflect decomposition of nitrogen-deficient organic substances rather than the relatively nitrogen-rich substances used in the chemical decomposition model. At the continental margin off West Africa, horizontal and vertical concentration profiles of nutrient constituents in the interstitial water indicate an increased flux of nutrients from the organic-rich sediments to the waters of the lower continental slope. The bottom water there contains increased amounts of dissolved phosphate and is depleted in oxygen. It is suggested that this is due to the combined effect of increased nutrient regeneration from within the sediments and from the sediment surface. Sediments from the deep Pacific Ocean characteristically show decreasing organic carbon and nitrogen depth-profiles near the depositional interface. This could be attributed to organic decomposition processes, i.e., to regeneration of nutrients. The loss of organic carbon and nitrogen from the sediment to the water equals possible molecular diffusion transport in the form of nitrate and dissolved organic constituents.

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