Two sampling protocols are used for the collection of benthic
invertebrates. The first protocol involves two people conducting a 15
minute search of all habitats in a 15 meter stream reach using hand
sieve and forceps to
collect a qualitative collection. Habitats included
sand, silt, gravel, rip-rap, large rocks, logs and vegetation.
The second protocol is a quantitative method using a t-sampler
within the riffle area of a stream. This method was selected to
calculate the density of invertebrates within the diameter of the
It provides valid comparisons between
samples, by relative abundance and will show any species and density
changes at a location. The open end of the sampler is placed into the
current and the substrate inside
the t-sampler is agitated for one minute and
allowed too clear. The flow of the water through the t-sampler will
carry any invertebrates through the net and into the catch bottle.
Contents of the catch bottle are placed in a white field tray and
all specimens are picked from the tray and net. The specimens are
preserved in seventy percent
alcohol and taken back to the lab for
identification using a stereo microscope.