Biological
Monitoring
Early
in 2000, Cheney Lake Watershed, Inc. applied for an Environmental
Protection Agency Water Quality Cooperative Agreement grant to study
benthic macroinvertebrates in the North Fork Ninnescah River and its
tributaries. The study of these tiny creatures and their habitat
provides farmers and other watershed stakeholders with a broader picture
of watershed health. The project included an educational component that
introduced farmers and other residents to biological monitoring and
emphasized the connections between land use and water quality. The
Cheney Lake Watershed board uses information gained from the
monitoring data to direct watershed funds and educational efforts to
specific practices or subwatersheds.
The Healthy
Stream
The
structure and function of a healthy aquatic community is dependent upon
the balance of various components. Water chemistry, nutrients, sunlight,
habitat quality, surrounding land use activity and other factors
contribute to the mechanical workings of a stream system, and
consequently the well being of the organisms living within it. When
certain elements become too abundant, some of the aquatic insects and
fish do poorly, while other organisms do very well.
When a stream system is out of balance, it is not just the organisms in
the stream that are affected.
Certain
types of bacteria and algae that favor this kind of environment, can be
harmful for livestock to drink, and can make drinking water taste poorly
if the stream is used for a municipal water supply.
Different organisms can tolerate different amounts of stress. Therefore,
the aquatic insects found in a stream that has a lot of stress from
pollution will be different than the insects found in a stream that is
not under stress from pollution. It is the biologist’s job to evaluate
the community of organisms living in a stream environment and determines
how healthy it is.
Monitoring the Stream
There are many organisms that
can be used to monitor aquatic environmental health In the Cheney Lake
Watershed
Biomonitoring Project, benthic macroinvertebrates (benthic=bottom of the
stream, macroinvertebrate=organisms without a backbone that you can see
without a microscope) were used.
There are many organisms that make up the group called benthic
macroinvertebrates including aquatic insects, clams, crustaceans
(crayfish, etc.), and aquatic worms. Various techniques have been
developed to take samples of the macroinvertebrate community. All of
them are standardized to provide “relative” abundances of each type of
macroinvertebrate. Various habitats are sampled within a stream to
collect organisms, which are stored in alcohol to be identified later in
the laboratory.
The bank along the stream is
prime habitat for a number of macroinvetebrate species.
Information from biomonitoring
studies has many uses. It can be used by watershed managers to evaluate
the more vulnerable areas of the watershed to be able to allocate
valuable resources for implementing best management practices. It can
help determine trends in water quality over time to evaluate the
effectiveness of changes in land use management. Biomonitoring data can
help protect land managers that utilize beneficial practices and help
point out areas that contribute pollution.
Lessons
Learned
At this point,
the biological monitoring data has indicated a few trends that are
useful for the Cheney Lake Watershed Project Coordinator and Citizen’s
Management Committee.
-
As the area in cropland increases within a sub-basin, there is a
decline in water quality.
-
Intermittent streams play an important role and contribute to the
well being of the watershed. As the cropland area around intermittent
streams increases, water quality decreases.
-
Soil erosion is contributing to water quality problems. As the area
of land with highly erodable soils increases, the water quality
decreases.
-
Proper management of rangelands and Conservation Reserve Program
grasslands is important. Good practices can lower the impact of land use
on streams, improving water quality.
-
There are certain areas within the watershed that are more vulnerable
to water quality impairment than others and would benefit from targeted
resource allocation.
