INTRODUCTION:
The Stream Team investigated Potash Brook which runs through East Woods in Burlington. We questioned many things most of which concerned the health of the river.
RESEARCH QUESTIONS:
1.) What are BMIs and what do they tell us about stream health?
The Stream Team investigated Potash Brook which runs through East Woods in Burlington. We questioned many things most of which concerned the health of the river.
RESEARCH QUESTIONS:
1.) What are BMIs and what do they tell us about stream health?
- BMI- Benthic Macro Invertabrates are
bottom dwelling
creatures without backbones that are big enough to see with the naked
eye. We looked at the density vs. the diversity of creatures we
found in the
river. If there is a diverse spread of creatures and a lot of
them, that suggests that the river is healthy. BMIs are good bioindicators because various
species have specific tolerances to impact on their habitat.
There is a tolerance index scale from 1 to
10, 1 being most sensitive and 10 being the most tolerant.
Creatures that are tolerant to impact can live in most waters whether
the habitat is healthy or not. But when you find creatures with a
low tolerance index then it is an indicator of good stream
health. However, not only do we concern ourselves with whether we
find any of them, but the size of the population matters as well.
For example, you may only find a few sensitive creatures but if you're
finding many of them, then that is a better sign of a stable and
healthy water way.
2.) How do the physical characteristics of
the habitat affect macro invertabrates' density and
diversity?
- We measured the stream discharge, percent of
adjacent plant canopy coverage, pH, dissolved oxygen & phosphorus
of the stream water,
and bottom substrate type.
3.)
How do stream characteristics vary with elevation or proximity to
sources of influence such as culverts and discharges?
- We noticed several point sources of inflows that entered the
river. One came from the highway into East Woods from Rt. 7, and
another from a water processing plant further downstream, close to the
Potash Brook's mouth into Lake Champlain. We were interested in
whether these inflow points affected the water chemistry and what kind
of life we could find there.
