Microbial activities accompanying decomposition of cladoceran and copepod carcasses under different environmental conditions

Abstract

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 57:89-100 (2009) - DOI: https://doi.org/10.3354/ame01331 Microbial activities accompanying decomposition of cladoceran and copepod carcasses under different environmental conditions Kam W. Tang1,*, Samantha L. Bickel1, Claudia Dziallas2, Hans-Peter Grossart2 1Virginia Institute of Marine Science, 1208 Greate Road, Gloucester Point, Virginia 23062, USA 2Leibniz Institute of Freshwater Ecology and Inland Fisheries, Alte Fischerhuette 2, 16775 Stechlin, Germany *Email: kamtang@vims.edu ABSTRACT: Cladoceran and copepod carcasses in both marine and freshwater environments represent concentrated reservoirs of organic substrates for water column bacteria. We studied the microbial abundance, activities, and diversity associated with decomposing carcasses of different zooplankton species over short and long time scales, and in oligotrophic vs. eutrophic environments. Fresh carcasses of Daphnia cucullata, Diaphanosoma brachyurum, and Eudiaptomus gracilis were rapidly colonized by bacteria, which reached peak abundances within 1.5 d at 20°C and then decreased. Cell-specific exoenzymatic activity on protein and lipid analogs and production rate of bacteria associated with the carcasses were all higher than in the ambient water. ANOSIM analyses of DGGE banding patterns revealed that bacterial communities associated with both cladoceran and copepod carcasses rapidly diverged from the initial bacterial community in the ambient water. The high similarity of bacteria on both types of carcasses indicates that the carcasses were decomposed by similar bacterial groups. Estimated carcass decomposition rate was lower at 6°C, with an estimated Q10 of 2.4. Carcasses suspended in the eutrophic Lake Dagow had a higher average carbon loss rate than those suspended in the oligotrophic Lake Stechlin. Cladoceran carcasses were initially colonized by bacteria faster than copepod carcasses in both laboratory and field experiments, suggesting that cladoceran carcasses were more prone to exploitation by bacteria, yet copepod carcasses lost carbon at higher rates. Overall, our results suggest that pelagic zooplankton production can be directly converted to water column bacterial production via carcass decomposition, especially during the mid-summer zooplankton decline commonly observed in lakes. KEY WORDS: Decomposition · Exoenzymes · Bacterial production · Bacterial community composition · Zooplankton carcasses Full text in pdf format PreviousNextCite this article as: Tang KW, Bickel SL, Dziallas C, Grossart HP (2009) Microbial activities accompanying decomposition of cladoceran and copepod carcasses under different environmental conditions. Aquat Microb Ecol 57:89-100. https://doi.org/10.3354/ame01331 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 57, No. 1. Online publication date: September 18, 2009 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2009 Inter-Research.