HR: 1330h
AN: NB33D-05    [Abstracts]
TI: Importance of DOC From Terrestrial Sources in Supporting Benthic Production in Arctic Lakes.
AU: * Binkley, E
EM: erbinkle@uncg.edu
AF: University of North Carolina - Greensboro, Biology Department 312 Eberhart Building , Greensboro, NC 27402 United States
AU: Fortino, K
EM: kfortino@email.unc.edu
AF: University of North Carolina at Chapel Hill, Rosenau Hall CB# 7431, Chapel Hill, NC 27599 United States
AU: Hershey, A
EM: aehershe@uncg.edu
AF: University of North Carolina - Greensboro, Biology Department 312 Eberhart Building , Greensboro, NC 27402 United States
AB: A prevailing paradigm in limnology has been that benthic organisms derive most of their food from pelagic productivity. However, chironomids are known to utilize dissolved organic carbon (DOC) via the microbial food web, and much DOC is derived from terrestrial sources. We tested whether supplements of various DOC and particulate organic carbon (POC) sources would support growth in Chironomus from arctic lakes. Eight treatments with five replicates were administered to Chironomus growing in sediment core microcosms over a twenty-four day period. Growth rates were calculated and stable isotope analysis of Chironomus δ¹³C data was performed. An overall ANOVA and a Tukey-Kramer's test were performed on the data. The stable isotope data established that Chironomus assimilated carbon from both pelagic algal-derived DOC and from benthic algae. However, only the terrestrial DOC supplement supported significantly positive growth. The terrestrial particulate detritus treatment showed lowest growth. We conclude that DOC-based production is important in supporting benthic food webs, and that much of this may be derived from terrestrial sources.
DE: 1845 Limnology
DE: 4239 Limnology
DE: 4804 Benthic processes/benthos
DE: 4817 Food chains
DE: 4845 Nutrients and nutrient cycling
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly