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Postdepositional mobility of phosphorus in lake sediments 1
Author(s) -
Carignan R.,
Flett R. J.
Publication year - 1981
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1981.26.2.0361
Subject(s) - sediment , phosphorus , sedimentation , nutrient , geology , environmental chemistry , chemistry , geomorphology , organic chemistry
Fifteen sediment cores from Lake Memphremagog showed pronounced peaks of total phosphorus concentration within the 210 Pb‐defined mixed layer, suggesting that P was migrating upward and accumulating near the mud surface. The mobility of P in the sediments was confirmed by the rapid development (5 weeks) of a marked total P maximum in the upper centimeter of a previously homogenized sediment. Associated with the P migration was a steep gradient of soluble reactive P (SRP) concentration, presumably the result of a redox gradient in the sediments. Similar gradients of total P and SRP were observed in nondisturbed sediments, strongly suggesting that such an upward migration mechanism also operates under natural conditions. The remobilized P seems to be isotopically exchangeable (mobile) under anaerobic conditions. These observations indicate that profiles of sediment total P may not always be useful in determining historical P loading or P sedimentation rates in lakes.