MBSS Site Summary for: PRLN-626-S-2006


Located on Mill Run in the Potomac River L N Branch watershed, 8-digit code: 02141001.
This stream was visited in the spring on 4/11/2006 and again in the summer on 7/6/2006.

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 Good - 4.0 / 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 15/20 (Suboptimal)
Epifaunal Substrate 12/20 (Suboptimal)
Velocity/Depth Diversity 10/20 (Marginal)
Pool Quality
Pool Extent = 20 meters
10/20 (Marginal)
Riffle Quality
Riffle Extent = 70 meters
15/20 (Suboptimal)
Shading 98 %
Embeddedness 30 %


Stream Water Quality:

Water temperature 16.1 ° C
Dissolved oxygen (DO) 8.1 mg/L
pH (lab) 7.93
Conductivity 186 µmho/cm
Alkalinity
(acid neutralizing capacity)
968.2 µeq/L
Dissolved organic carbon (DOC) 0.7837 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 51
Blue Ridge Sculpin 23
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:

Northern Green Frog

Crayfish:

Cambarus bartonii bartonii

Exotic Plants:

Japanese Stiltgrass
 

Benthic Macroinvertebrates:

Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Micropsectra Non-Biting Midges 20
Cinygmula Dark Red Quill Mayfly 10
Diplectrona Net-Spinning Caddisfly 5
Amphinemura Spring Stonefly 4
Isoperla Stripetail Stonefly 4
Diamesa Bloodworm 4
Baetis Blue-Winged Olive Mayfly 4
Parametriocnemus Non-Biting Midges 4
Clinocera Aquatic Dance Fly 4
Epeorus Mayfly 4
Prosimulium Black Fly 3
Tanytarsini Non-Biting Midges 3
Leptophlebiidae Pronggilled Mayfly 3
Ephemerella Sulphur Mayfly 3
Alloperla Stonefly 2
Heleniella European Non-Biting Midge 2
Heptageniidae Flathead Mayfly 1
Chloroperlidae Green Stonefly 1
Haploperla Green Stonefly 1
Perlidae Common Stonefly 1
Hexatoma Crane Fly 1
Baetidae Small Minnow Mayfly 1
Simulium Black Fly 1
Orthocladiinae Midge 1
Hydropsyche Net-Spinning Caddisfly 1
Ectopria Water Penny Beetle 1
Leuctra  Rolled-Winged Stonefly 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.