title: Estimation of long-term bacterial respiration and growth efficiency in Lake Kinneret.
abstract: Semi-annual averaged values of photosynthetic carbon fixation (PCF), community respiration (CR), bacterial productivity (BP) and zooplankton carbon biomass, measured biweekly or monthly, were used to obtain long-term estimates of bacterial respiration (BR) and bacterial growth efficiency (BGE) in Lake Kinneret from 2001 through 2007. We posited that CR=BR+phytoplankton respiration (PR)+zooplankton respiration (ZR). Based on the results of independent experimental series, PR was estimated as 0.3 x gross primary production (GPP) and GPP as 1.5 x PCF. ZR was determined by multiplying zooplankton carbon biomass, measured biweekly, with published respiration rates for major zooplankton groups. From these data, we calculated BR and consequently BGE, determined as BP/(BR+BP). Over the entire study period, BR averaged 49 (+/-10)% of CR and was consistently higher during the first half of the year. Semi-annual averaged BGE ranged from 26% to 53%, mean 39 (+/-9)%. Similar values of BGE were obtained if we did not use the measured values for ZR, but estimated BR+ZR from CR-PR and then assumed that BR ranged from two to three times ZR. The approach outlined in this paper can be useful for determining BGE in aquatic systems where long-term data sets of PCF, CR and BP are available.
authors.affiliation: Israel Oceanographic and Limnological Research, Yigal Alon Kinneret Limnological Laboratory, Migdal, Israel. tberman@ocean.org.il
authors.forename: Tom
authors.initials: T
authors.lastname: Berman
authors.forename: Yosef Z
authors.initials: YZ
authors.lastname: Yacobi
authors.forename: Arkadi
authors.initials: A
authors.lastname: Parparov
authors.forename: Gideon
authors.initials: G
authors.lastname: Gal
mesh_terms: D000818:Animals; D001419:Bacteria / Q000254:growth & development*; D018533:Biomass; D002244:Carbon / Q000378:metabolism; D005618:Fresh Water; D010788:Photosynthesis; D010839:Phytoplankton / Q000254:growth & development; D014871:Water Microbiology; D015048:Zooplankton / Q000254:growth & development
chemical_list: D002244:Carbon