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Variable retention of diatoms on screens during size separations
Author(s) -
Logan Bruce E.,
Passow Uta,
Alldredge Alice L.
Publication year - 1994
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.1994.39.2.0390
Subject(s) - thalassiosira weissflogii , diatom , cell size , flocculation , chemistry , fiber , phytoplankton , biology , chromatography , botany , ecology , microbiology and biotechnology , organic chemistry , nutrient
Particles smaller than filter mesh pores can collide and stick to mesh fibers, biasing size separations based only on pore diameter. The removal of flocculating diatoms ( Chaetoceros gracilis, Nitzschia angularis ) was greater than removal of a nonfloc‐forming species ( Thalassiosira weissflogii ) even after including the effects of cell size. Over a 5‐d period an average of 1.4% of cells of N. angularis were removed by 230‐ µ m pore‐diameter screens; on day 6, 7.5% of cells were removed as cells began to flocculate. The percentage of C. gracilis removed continually increased from 0.4 to 28% during the same period, while the removal of T. weissflogii was constant at 0.19% over a 10‐d period. Prior to the onset of flocculation, sticking coefficients (rate of cell attachment to mesh fibers/rate striking fibers) were 0.05 for T. weissflogii , 0.26 for N. angularis , and 0.73 for C. gracilis . Size separations will therefore tend to concentrate more flocculent species of phytoplankton into size fractions much larger than cell diameters.