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Periodic bacterivore activity balances bacterial growth in the marine environment
Author(s) -
Johan Wikner,
Rassoulzadegan Fereidoun,
Hagström Åke
Publication year - 1990
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1990.35.2.0313
Subject(s) - grazing , diel vertical migration , pelagic zone , bacterivore , zoology , biology , biomass (ecology) , growth rate , bacteria , bacterial growth , ecology , predation , genetics , geometry , mathematics
The grazing rate of pelagic bacteria was repeatedly determined during 36‐h time‐course experiments with the minicell recapture technique. Diel variation in the rate of grazing occurred in all water masses investigated. Maximal rates reached 2 × 10 5 cells ml −1 h −1 , whereas minimal values were 20 times lower. Highest grazing rates were found during the day in most cases, but grazing could also dominate at night as found in one study. Diel periodicity was mainly due to variation in the per‐cell feeding rate of bacterivorous flagellates. Accumulation of the bacterial biomass into the 1–3‐ µ m size fraction was positively correlated with changes in bacterial grazing. The transfer efficiency to organisms >10 µ m was low. On average, the daily grazing rate equaled 60% of the bacterial standing stock, exceeding bacterial growth by a factor of 2.6, as estimated from [ 3 H]thymidine incorporation.