MBSS Site Summary for: PRLN-626-S-2007

Site Photos

Field photo showing stream conditions at site PRLN-626-S-2007-1 (Opens in a new window) Field photo showing stream conditions at site PRLN-626-S-2007-2 (Opens in a new window)

Located on Mill Run in the Potomac River L N Branch watershed, 8-digit code: 02141001.
This stream was visited in the spring on 4/5/2007 and again in the summer on 6/18/2007.

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 - 3.0 / 5.0
Benthic IBI Fair - 3.8 / 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 18/20 (Optimal)
Epifaunal Substrate 18/20 (Optimal)
Velocity/Depth Diversity 10/20 (Marginal)
Pool Quality
Pool Extent = 30 meters 		11/20 (Suboptimal)
Riffle Quality
Riffle Extent = 59 meters 		17/20 (Optimal)
Shading 95 %
Embeddedness 20 %
Several measures of instream habitat were considered 'Optimal' at this location.


Stream Water Quality:
Water temperature 16.6 ° C
Dissolved oxygen (DO) 7.6 mg/L
pH (lab) 7.64
Conductivity 171 µmho/cm
Alkalinity
(acid neutralizing capacity) 		622.9 µeq/L
Dissolved organic carbon (DOC) 0.8762 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 90
Blue Ridge Sculpin 28
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Eastern Fence Lizard
Northern Dusky Salamander
Northern Green Frog

Crayfish:
Cambarus bartonii bartonii

Exotic Plants:
Garlic Mustard
Japanese Stiltgrass
Multiflora Rose
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Prosimulium Black Fly 25
Amphinemura Spring Stonefly 17
Epeorus Mayfly 9
Leptophlebiidae Pronggilled Mayfly 7
Heptageniidae Flathead Mayfly 5
Perlidae Common Stonefly 5
Hexatoma Crane Fly 5
Baetidae Small Minnow Mayfly 5
Ephemerella Sulphur Mayfly 5
Pteronarcys Giant Stonefly 4
Diplectrona Net-Spinning Caddisfly 3
Oulimnius Riffle Beetle 2
Neophylax Caddisfly 2
Ectopria Water Penny Beetle 2
Probezzia Biting Midges 1
Isoperla Stripetail Stonefly 1
Ameletus Combmouthed Minnow Mayfly 1
Rhyacophila Free-Living Caddisfly 1
Pseudolimnophila Crane Fly 1
Heleniella European Non-Biting Midge 1
Acroneuria Golden Stoneflies 1
Chloroperlidae Green Stonefly 1
Dicranota Hairy-Eyed Cranefly 1
Lepidostoma Little Brown Sedge Caddisfly 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.