Quayle, W. C. British Antarctic Survey, wcq@pcmail.nerc-bas.ac.uk
, . C. ,

 
CHEMISTRY AND SOURCE OF DISSOLVED SACCHARIDES AND AMINO ACIDS IN MARITIME ANTARCTIC LAKES
 
Dissolved organic matter (DOM) from four Maritime Antarctic lakes has been separated into two size fractions of <1000 Da and >1000 Da using tangential flow ultra-filtration. The contribution of saccharides and amino acids to DOM in the two size fractions has been determined using a combination of wet chemical techniques and PAD-HPLC. The abundance, distribution and molecular weight of these compounds are considered to have a significant control on the bioavailability of DOM in a range of aquatic environments. Preliminary results demonstrate that fructose, glucose and sucrose dominate the <1000 Da saccharide pool and sugar alcohols are apparently more abundant in this fraction than the neutral sugars. This saccharide distribution is characteristic of mosses and lichens growing in lake catchment areas in the Maritime Antarctic. The data suggests that a significant contribution of bioavailable DOM is made from plants in the lake catchments rather than being autocthonously derived. The four study lakes represent a range of trophic status. Increasing numbers of fur seals in Heywood Lake has caused eutrophication while Sombre Lake has been affected to a lesser extent. Light Lake has a seabird colony immediately adjacent. These lakes are contrasted with Moss Lake which is oligotrophic. SS34 SS33 CS07 Either oral or poster
 
Day: Tuesday, Feb. 2
Time: 02:30 - 02:45pm
Location: Eldorado Hotel
 
Code: SS34TU0230E