MBSS Site Summary for: PRLN-113-R-2003

Site Photos

Located on TOMS HOLLOW CR in the Potomac River L N Branch watershed, 8-digit code: 02141001.
This stream was visited in the spring on 3/26/2003 and again in the summer on 6/18/2003.

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 - 2.0 / 5.0
Benthic IBI Good - 4.8 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 608 acres A stream flowing through a densely forested area. An example of a forested stream.
Urban Land Use 0 %
Agricultural Land Use 3 %
Forested Land Use 72 %


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 19/20 (Optimal)
Velocity/Depth Diversity 10/20 (Marginal)
Pool Quality
Pool Extent = 9 meters 		10/20 (Marginal)
Riffle Quality
Riffle Extent = 75 meters 		19/20 (Optimal)
Shading 98 %
Embeddedness 15 %
Several measures of instream habitat were considered 'Optimal' at this location.


Stream Water Quality:
Water temperature 11.9 ° C
Dissolved oxygen (DO) 10.1 mg/L
pH (lab) 7.53
Conductivity 94 µmho/cm
Alkalinity
(acid neutralizing capacity) 		355 µeq/L
Dissolved organic carbon (DOC) 1.6 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
Blacknose Dace 117
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Northern Dusky Salamander

Crayfish:
No crayfish noted.

Exotic Plants:
No exotic plants noted.
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Epeorus Mayfly 28
Amphinemura Spring Stonefly 19
Leptophlebiidae Pronggilled Mayfly 12
Diplectrona Net-Spinning Caddisfly 9
Leuctra  Rolled-Winged Stonefly 9
Prosimulium Black Fly 8
Ephemerella Sulphur Mayfly 7
Micropsectra Non-Biting Midges 5
Neophylax Caddisfly 5
Acroneuria Golden Stoneflies 3
Diamesa Bloodworm 3
Ameletus Combmouthed Minnow Mayfly 3
Perlidae Common Stonefly 3
Hexatoma Crane Fly 3
Tanytarsini Non-Biting Midges 3
Stempellinella Non-Biting Midges 2
Rhyacophila Free-Living Caddisfly 2
Eukiefferiella Non-Biting Midges 2
Chloroperlidae Green Stonefly 2
Dicranota Hairy-Eyed Cranefly 2
Dolophilodes Medium Evening Sedge Caddisfly 2
Hydropsyche Net-Spinning Caddisfly 1
Brillia Non-Biting Midges 1
Gomphidae Clubtail Dragonfly 1
Pseudolimnophila Crane Fly 1
Heptageniidae Flathead Mayfly 1
Stenonema Flatheaded Mayfly 1
Ceratopogon Biting Midge 1
Parametriocnemus Non-Biting Midges 1
Thienemannimyia group 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.