MBSS Site Summary for: PRWA-106-R-2000

Site Photos

Field photo showing stream conditions at site PRWA-106-R-2000-01 (Opens in a new window) Field photo showing stream conditions at site PRWA-106-R-2000-02 (Opens in a new window)

Located on DOWNEY BR in the Potomac River WA Cnty watershed, 8-digit code: 02140501.
This stream was visited in the spring on 3/29/2000 and again in the summer on 8/29/2000.

Index of Biotic Integrity (IBI) Results:

An Index of Biotic Integrity (IBI) is a scientific tool used to identify and classify stream health. An IBI associates anthropogenic influences on a stream or with biological condition in the stream, and is formulated using data developed from biosurveys.
Details on the development and application of MBSS IBIs are in this document.
Fish IBI Poor - 1.0 / 5.0
Benthic IBI Poor - 1.8 / 5.0

Land Use

Land use can provide important information for determining stream health.
(Hint: Screen readers will announce definitions; mouse users can hover over dotted text.)
Catchment area 1,370 acres Cows standing in a stream at a site with high agricultural land use. Cows survey the sampling procedure at this extreme example of a highly agriculturalized site.
Urban Land Use 1.2 %
Agricultural Land Use 93.1 %
Forested Land Use 5.5 %


Stream showing woody debris, logs, and rocky substrate.
An example of woody debris in a stream.

Physical Stream Habitat
Instream Habitat 15/20 (Suboptimal)
Epifaunal Substrate 6/20 (Marginal)
Velocity/Depth Diversity 10/20 (Marginal)
Pool Quality
Pool Extent = 45 meters 		14/20 (Suboptimal)
Riffle Quality
Riffle Extent = 35 meters 		16/20 (Optimal)
Shading 92 %
Embeddedness 75 %
The embeddedness, a measure of silt on the stream bottom, was 75%. This is relatively high, and may exclude some biota.


Stream Water Quality:
Water temperature 16.9 ° C
Dissolved oxygen (DO) 8.9 mg/L
pH (lab) 8.27
Conductivity 260 µmho/cm
Alkalinity
(acid neutralizing capacity) 		6056 µeq/L
Dissolved organic carbon (DOC) 1 mg/L

Biological Stream Condition:

Surveys of the organisms living within a stream can give indications of stream health. Species richness, or the number of different species present, as well as indicator species (species whose presence, absence or abundance can serve as a measure of environmental conditions) are informative for stream health. 		Close-up of a mayfly indicator species.

Fish Survey Results:
The following 1 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
No Fish Observed 0
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
No amphibians and reptiles noted.

Crayfish:
No crayfish noted.

Exotic Plants:
Canada Thistle
Multiflora Rose
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Gammarus Amphipod 86
Polypedilum Non-Biting Midges 16
Parametriocnemus Non-Biting Midges 9
Micropsectra Non-Biting Midges 7
Prodiamesa 5
Stenelmis Beetle 4
Cricotopus/Orthocladius Midge 3
Tvetenia Non-Biting Midges 3
Hydropsyche Net-Spinning Caddisfly 2
Dixa 1
Paraleptophlebia Blue Quill Mayfly 1
Caecidotea Isopod 1
Kick net sampling for macroinvertebrates.
Sampling with a kick net.

Information disclaimer: The information and data on this page is for guidance and general planning purposes only. It should not be used to make decisions on specific matters.