MBSS Site Summary for: PRLN-626-S-2004


Located on MILL RUN in the Potomac River L N Branch watershed, 8-digit code: 02141001.
This stream was visited in the spring on 3/25/2004 and again in the summer on 7/13/2004.

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 Fair - 3.5 / 5.0
Benthic IBI Good - 4.0 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 484 acres A stream flowing through a densely forested area. An example of a forested stream.
Urban Land Use 0.5 %
Agricultural Land Use 2.5 %
Forested Land Use 64.6 %


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

Physical Stream Habitat
Instream Habitat 16/20 (Optimal)
Epifaunal Substrate 16/20 (Optimal)
Velocity/Depth Diversity 10/20 (Marginal)
Pool Quality
Pool Extent = 39 meters 		14/20 (Suboptimal)
Riffle Quality
Riffle Extent = 67 meters 		15/20 (Suboptimal)
Shading 90 %
Embeddedness 35 %


Stream Water Quality:
Water temperature 19.7 ° C
Dissolved oxygen (DO) 8.3 mg/L
pH (lab) 7.46
Conductivity 156 µmho/cm
Alkalinity
(acid neutralizing capacity) 		423.8 µeq/L
Dissolved organic carbon (DOC) 0.9 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 2 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Blacknose Dace 79
Blue Ridge Sculpin 40
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Northern Green Frog

Crayfish:
No crayfish noted.

Exotic Plants:
Japanese Stiltgrass
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Epeorus Mayfly 38
Baetis Blue-Winged Olive Mayfly 15
Prosimulium Black Fly 14
Paraleptophlebia Blue Quill Mayfly 8
Diplectrona Net-Spinning Caddisfly 8
Isoperla Stripetail Stonefly 7
Leuctra  Rolled-Winged Stonefly 4
Neophylax Caddisfly 4
Hydropsyche Net-Spinning Caddisfly 3
Micropsectra Non-Biting Midges 3
Ephemerella Sulphur Mayfly 2
Parametriocnemus Non-Biting Midges 2
Perlidae Common Stonefly 2
Rhyacophila Free-Living Caddisfly 2
Pteronarcys Giant Stonefly 2
Chloroperlidae Green Stonefly 2
Ceratopogon Biting Midge 1
Microtendipes Non-Biting Midges 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.