TY - JOUR

T1 - Dissolved organic matter and nutrients in the Lena River, Siberian Arctic: Characteristics and distribution

AU - Lara, Rubén J.

AU - Rachold, Volker

AU - Kattner, Gerhard

AU - Hubberten, Hans W.

AU - Guggenberger, Georg

AU - Skoog, Annelie

AU - Thomas, David N.

N1 - Funding information: The authors wish to thank V.N. Korotaev for organizing the Lena '94 expedition. Special thanks to the captain and crew members of RV ``Professor Makkaveev''. Thanks also to B. Kirchhoff, B. Hollmann, M. Stürcken-Rodewald and K.-U. Richter for their excellent analytical assistance. This study is funded by the ``Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie (BMBF)'' within the ``Verbundvorhaben System Laptev See'' and by the ``Programm zur Förderung besonderer Forschungsthemen (AWI)''. This is publication No. 1150 of the Alfred-Wegener-Institut.

PY - 1998/6/15

Y1 - 1998/6/15

N2 - Dissolved organic carbon (DOC) and nitrogen (DON), amino acids, carbohydrates and inorganic nutrients were measured on samples taken in July 1994 at 18 stations between Yakutsk and the Lena delta, East Siberia. There were no obvious gradients or features along the river, except in the tributaries, the Aldan and Vilyuy rivers, where significantly higher concentrations of several parameters were measured. Concentrations of DOC varied between 300 and 1000 μM C, with most values varying between 500 and 700 μM C (mean 570 μM C). DON concentrations ranged between 9 and 28 μM N (mean 13 μM N). The C/N ratios of bulk dissolved organic matter (DOM) varied from 30 to 58, with 75% of the values being between 45 and 55 (mean 48). Total dissolved amino acids (TDAA) ranged between 1.6 and 5.4 μM, averaged about 3.5 μM, mostly in the combined form, and represented about 28% of the DON. Free amino acids were only about 2% of TDAA. Glycine, aspartic acid and glutamic acid predominated, accounting for about 41% of TDAA. Total dissolved carbohydrates ranged from 190 to 470 μg glucose equivalents l-1 and averaged 299 μg l-1, forming only 1.2 to 2.5% of the DOC pool. The following ranges of inorganic nutrients were measured: nitrate, 0.01 to 1.4 μM N (mean 0.6 μM N); nitrite, 0.03 to 0.1 μM N (mean 0.07 μM N); ammonium, 0.01 to 0.3 μM N (mean 0.13 μM N); phosphate, 0.2 to 1 μM P (mean 0.5 μMP); silicate, 59 to 87 μM Si (mean 66 μM Si). Carbon isotope data of the suspended organic material suggest that the low inorganic nitrogen values are not due to algal uptake, but rather an inherent characteristic of the river and the catchment area. This, together with positive correlations between silicate, DOC and DON and high C/N values, suggests that the composition of DOM in the Lena River is mainly determined by the input of soil-derived, recalcitrant material and not by autochthonous sources.

AB - Dissolved organic carbon (DOC) and nitrogen (DON), amino acids, carbohydrates and inorganic nutrients were measured on samples taken in July 1994 at 18 stations between Yakutsk and the Lena delta, East Siberia. There were no obvious gradients or features along the river, except in the tributaries, the Aldan and Vilyuy rivers, where significantly higher concentrations of several parameters were measured. Concentrations of DOC varied between 300 and 1000 μM C, with most values varying between 500 and 700 μM C (mean 570 μM C). DON concentrations ranged between 9 and 28 μM N (mean 13 μM N). The C/N ratios of bulk dissolved organic matter (DOM) varied from 30 to 58, with 75% of the values being between 45 and 55 (mean 48). Total dissolved amino acids (TDAA) ranged between 1.6 and 5.4 μM, averaged about 3.5 μM, mostly in the combined form, and represented about 28% of the DON. Free amino acids were only about 2% of TDAA. Glycine, aspartic acid and glutamic acid predominated, accounting for about 41% of TDAA. Total dissolved carbohydrates ranged from 190 to 470 μg glucose equivalents l-1 and averaged 299 μg l-1, forming only 1.2 to 2.5% of the DOC pool. The following ranges of inorganic nutrients were measured: nitrate, 0.01 to 1.4 μM N (mean 0.6 μM N); nitrite, 0.03 to 0.1 μM N (mean 0.07 μM N); ammonium, 0.01 to 0.3 μM N (mean 0.13 μM N); phosphate, 0.2 to 1 μM P (mean 0.5 μMP); silicate, 59 to 87 μM Si (mean 66 μM Si). Carbon isotope data of the suspended organic material suggest that the low inorganic nitrogen values are not due to algal uptake, but rather an inherent characteristic of the river and the catchment area. This, together with positive correlations between silicate, DOC and DON and high C/N values, suggests that the composition of DOM in the Lena River is mainly determined by the input of soil-derived, recalcitrant material and not by autochthonous sources.

KW - Amino acids

KW - Carbohydrates

KW - Dissolved organic carbon

KW - Lena River

KW - Nitrogen

KW - Nutrients

UR - http://www.scopus.com/inward/record.url?scp=0031921752&partnerID=8YFLogxK

U2 - 10.1016/S0304-4203(97)00076-5

DO - 10.1016/S0304-4203(97)00076-5

M3 - Article

AN - SCOPUS:0031921752

VL - 59

SP - 301

EP - 309

JO - Marine chemistry

JF - Marine chemistry

SN - 0304-4203

IS - 3-4

ER -