Resource managers rely
upon habitat and water
quality monitoring data to characterize problem areas
in a watershed and to detect
changes related to management strategies to reduce nutrients
and sediments on a tributary to Bay-wide level. Traditional monitoring programs have
collected periodic data at a small number of fixed sampling
locations, often in the deeper channel areas. These measurements
provide a good baseline for watershed assessment and long-term
trends, but may miss small-scale gradients in water quality
and neglect shallow water habitats that are critical habitat
for submerged
aquatic vegetation (SAV) and other living resources.
Submerged Aquatic Vegetation, Severn River
In the past, intensive water quality monitoring
of these shallow water habitats has been time and cost-prohibitive. The advent of a new suite of technologies known as the DATAFLOW
water quality monitoring system, however, has brought intensive
monitoring of shallow water habitats into reach. DATAFLOW
is a system of shipboard water quality probes that measure
spatial position, water depth, water temperature, salinity,
dissolved oxygen, turbidity (clarity of the water), and chlorophyll
(indicator of plankton concentrations) from a flow-through
stream of water collected near the water body’s surface
(View Pictures and
Description of the DATAFLOW Instrumentation). This
system allows data to be collected rapidly (approximately
every 4 seconds) and while the boat is traveling at speeds
up to 20 knots. Because
the DATAFLOW system is compact, it can be housed on a small
boat, enabling sampling in shallow water and the ability
to map an entire small Bay tributary in less than a day. Typical DATAFLOW research cruise
sampling paths traverse shallow and channel areas in a “right
angle” wave-like pattern to obtain a full characterization
of a tributary’s water quality.
Results from DATAFLOW can address many of
the key management issues addressed in the Chesapeake Bay
2000 Agreement. DATAFLOW
habitat parameters such as turbidity can be correlated to
the spatial coverage of SAV to: determine water clarity criteria
necessary to support SAV growth, address the progress of
meeting ambitious SAV restoration goals, and target specific
areas for successful SAV restoration. Spatially
extensive DATAFLOW data can also be used to identify localized
areas of water quality concern within watersheds, such as
areas of low dissolved oxygen that can cause fish kills,
and its possible linkages with nearby land usage. Data can
also be used to aggregate across watersheds units to
aid in the evaluation of entire systems. For examples of
applications using DATAFLOW data, see Eyes
on the Bay Monitoring Stories.
In 2011, the Water Quality Mapping Program will cover 5 segments of the Chesapeake Bay watershed. The Big Annemessex, Corsica, Manokin, and Patapsco Rivers will be mapped, as well as the main Bay between the mouth of the Back River and the Bay Bridge. Visit the Water
Quality Mapping Data Page to view preliminary maps of DATAFLOW-collected
data or Eyes on the
Bay to access all of Maryland DNR's online
tidal water quality data.
Eyes on the Bay Station Map - Click to go
to Eyes on the Bay
Maryland
DNR, Chesapeake
Biological Laboratory,
Virginia Department
of Environmental Quality, Virginia
Institute of Marine Science, and the EPA
Chesapeake Bay Program are
working together to use DATAFLOW and continuous monitors
to assess shallow water habitats and dissolved oxygen, chlorophyll,
and water
clarity
criteria for the Chesapeake Bay. These organizations work
together to develop consistent data collection protocols
and conduct optimal analyses to characterize water quality
and guide Chesapeake Bay management plans.
Water Quality
Mapping sampling design, data collection and data QA/QC
are performed by Maryland
DNR and Walter
Boynton's research group at the University
of Maryland's Center for Environmental Studies, Chesapeake
Biological Laboratory. The original DATAFLOW
equipment design was conceived by Christopher
Madden and
refined by Dr. Boynton's group. Funding
for this project is provided by the Environmental Protection
Agency's Chesapeake
Bay Program and the Maryland
Department of Natural Resources.
For More Information on Water
Quality Mapping,
Contact: Mark Trice