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Short‐term changes in the erodibility of intertidal cohesive sediments related to the migratory behavior of epipelic diatoms
Author(s) -
Paterson David M.
Publication year - 1989
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.1989.34.1.0223
Subject(s) - diatom , intertidal zone , sediment , tidal flat , mucilage , extracellular polymeric substance , matrix (chemical analysis) , benthic zone , oceanography , geology , environmental science , ecology , chemistry , biology , geomorphology , paleontology , chromatography , biofilm , bacteria
The surface stability of intertidal cohesive sediments maintained in a laboratory tidal ecosystem was examined in relation to the migratory behavior of epipelic diatoms. Stability was measured by a new portable device—a cohesive strength meter. Diatom#x2010;inhabited sediments increased significantly in surface stability over 7.3#x2010;h tidal exposure as compared with consolidated and unconsolidated control sediments. Low#x2010;temperature scanning electron microscopy showed an extensive extracellular matrix throughout the surface of diatom#x2010;inhabited sediments. This matrix was considered to consist mainly of mucopolysaccharides produced by diatoms as part of their locomotive mechanism. A matrix of very fine strands (possibly of bacterial origin) was found on the consolidated control sediment but had little effect on stability. Surface stability imparted by the mucilage produced by epipelic diatoms decayed after the return of the tide, but when dense populations of diatoms were present (10 6 diatoms cm −2 ) some residual stability remained after a full tidal inundation.