3.9 Experimental methods
ow needs to be resolved close to the organism, which represents a challenge due to
interactions of particles with the organism body.
Tracked prey particles, e.g., bacteria, or Brownian particles in a free domain can be
used to calculate an eective diusion coecient or parameters of ballistic motion that
then can be used in clearance rate formulas. Finally biological experiments on grazing
such as incubation experiments and gut content analysis can be used to estimate
ingestion rates and to infer encounter rates from that, if the retention and assimilation
eciencies are known.