Abstract: The effects of bioturbation on sediments are
increasingly gaining attention, but the potential of macrobenthos activity to
sediment erodibility in the modern
Yellow River
estuary has not been suggested previously. Field experiments were performed in
a representative site. Three adjacent experimental plots with varying degrees of
bioturbation were selected. Cave statistics and selected physical-mechanical
sediment properties at mounds and pits were conducted in succession. Sediment
erodibility was defined by critical erosion velocity and
critical erosion shear stresswas measured using a recirculating seawater flume which was designed and
constructed according to the mobile recirculating flume (MORF), andwas calculated based onTo quantitatively describe the degree of bioturbation, surface
disturbance index (D) was defined, i.e., the areal ratio between the sum of all
cave entrances and the selected experimental plot.
Field observations suggest that bioturbation enhances
the vertical transport of sediments. Statistical analysis
of geotechnical properties of surficial sediments show that biological
activities make surficial sediments finer and decrease its strength, but produce
little influence on the clay particle content. and significantly decrease in response to the increase of surface disturbance
index (D). All results indicate that increasing degree of bioturbation is
associated with increasing sediment erodibility in the Yellow River estuary.
Keywords and phrases: bioturbation, erodibility, intertidal sediments, recirculating seawater flume, Yellow River estuary.
