SEASONAL DIVERSITY OF MACROINVERTEBRATES IN THE SPRING BROOK WATERSHED

1
SEASONAL DIVERSITY OF MACROINVERTEBRATES IN THE
SPRING BROOK WATERSHED
DATA INTERPRETATION
PROBLEM
A macro invert index is a procedure used in the
evaluation of stream pollution. By finding the
quantity and diversity of macros throughout the
year a seasonal comparison can be calculated and
graphed. When observing
tolerance levels our graphs show macro
invertebrate samples from Spring Brook are mostly
those found in categories of very to moderately
tolerant to pollution.
WHAT EFFECT DOES SEASONAL CHANGE AND FLUCUATING
WATER LEVELS HAVE ON MACROINVERTEBRATE
POPULATIONS?
HYPOTHESIES Due to the effects of extreme water
levels and seasonal impact, the biotic index will
change over the course of the year.
PREDICTION Over the course of the year, as
temperatures increase and water levels decrease,
there will be fewer intolerant macros. As water
levels decrease the surface area decreases,
affecting stream flow, nutrient levels, and
dissolved oxygen.
PROCEDURE

• The objective is to asses the water quality in a
  stream by looking for pollution sensitive
  organisms.
• Collect macro inverts using a variety of sampling
  techniques. (Ex.) D-net, artificially built
  substrates, and stream substrate scrapings
• Divide the sample into the four biotic
• tolerance categories
• Using the given equation find the
• biotic index of the stream

CONCLUSION
The overall effects of high fluctuating water
levels and the wide variation of nutrient levels
indicates a stream system most suitable for
tolerant to very tolerant macro-invertebrates.
The biotic index shows that Spring Brook over a
three year average has a poor stream quality.