Original paper
A biogeochemical survey of rivers and streams in the mountains and foot-hills province of arctic Alaska
Lock, M. A.; Ford, T. E.; Fiebig, D. M.; Miller, M. C.; Hullar, M.; Kaufman, M.; Vestal, J. R.; Peterson, B. J.; Hobbie, J. E.
Archiv für Hydrobiologie Volume 115 Number 4 (1989), p. 499 - 521
39 references
published: Jun 27, 1989
DOI: 10.1127/archiv-hydrobiol/115/1989/499
ArtNo. ESP141011504001, Price: 29.00 €
Abstract
Ten rivers and streams were sampled in the mountain and foothills provinces of arctic Alaska in the vicinity of the Brooks Mountain range. Emphasis was upon the organic composition of the water including dissolved organic carbon, apparent molecular weight (AMW) fractions (0.7 µm-300K, 300—50K, 50—10K, 10—1K and <1k), uv-visible absorption spectra and free dissolved amino acids plus analyses for conductivity, ph, alkalinity, srp, no3-N, NO2-N, NH4-N, Ca, Mg, K and Na were also carried out. In addition waters were also monitored for chlorophyll-a content, bacterial densities and suspended microbial activity. The mountain and foothills rivers were separable on the basis of dissolved organic carbon content with low concentrations (0.18—1.84 mg OC l-1) in the mountains and high concentrations (2.27—8.41 OC l-1 in the foothills, apparent molecular weight spectra (foothills water characterized by its higher AMW composition) and UV-visible spectra. The concentrations of amino acids were extremely variable (3.7—272 µg l-1) throughout the study area but the % composition for each river were broadly similar. The mountain rivers were generally characterized by high ionic contents and the foothills by low ionic contents, while inorganic nitrogen and phosphorus concentrations were variable throughout the study area, although the molar N: P ratio (average 114) indicated that all the rivers were phosphorus limited. There were no discernible regional trends in the concentration of suspended chlorophyll-a, while bacterial concentrations (average 0.96 x 105ml-1) and microbial activity as 14C acetate incorporation into lipids were generally higher in the foothills province than in the mountain province (average 736DPM ml-1 h-1). Notably, the cell specific microbial activity was negatively correlated with ammonium concentrations and several amino acids.
Keywords
absorption spectra • molecular weight • ionic contents • amino acids • phosophorus concentrations • foothills provinces of artic Alaska in the vicinity of the Brooks Mountain range