MBSS Site Summary for: PG-N-257-324-97


Located on HENSON CR in the Potomac River U tidal watershed, 8-digit code: 02140201.
This stream was visited in the spring on 3/11/1997 and again in the summer on 6/11/1997.

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 - 3.7 / 5.0
Benthic IBI Fair - 3.3 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 9,376 acres A highly channelized urban stream with concrete banks. An example of a highly channelized urban stream.
Urban Land Use 55.6 %
Agricultural Land Use 11.6 %
Forested Land Use 29.6 %


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 16/20 (Optimal)
Velocity/Depth Diversity 11/20 (Suboptimal)
Pool Quality
Pool Extent = meters 		19/20 (Optimal)
Riffle Quality 11/20 (Suboptimal)
Shading 80 %
Embeddedness 40 %
Several measures of instream habitat were considered 'Optimal' at this location.


Stream Water Quality:
Water temperature 19 ° C
Dissolved oxygen (DO) 9.4 mg/L
pH (lab) 7.35
Conductivity 280 µmho/cm
Alkalinity
(acid neutralizing capacity) 		713.7 µeq/L
Dissolved organic carbon (DOC) 3.1 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 16 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Swallowtail Shiner 92
Redbreast Sunfish 73
Creek Chub 68
Tessellated Darter 46
American Eel 33
Blacknose Dace 17
Satinfin Shiner 15
White Sucker 11
Green Sunfish 8
Creek Chubsucker 5
Common Shiner 4
Bluegill 2
Common Carp 2
Golden Shiner 1
Rosyside Dace 1
Yellow Bullhead 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Eastern Ratsnake
Northern Two-Lined Salamander

Crayfish:
Orconectes

Exotic Plants:
No exotic plants noted.
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Naididae Aquatic Worm 15
Rheocricotopus Non-Biting Midges 12
Argia Narrow-Winged Damselfly 8
Rheotanytarsus Non-Biting Midges 5
Cricotopus Non-Biting Midges 5
Cricotopus/Orthocladius Midge 5
Coenagrionidae Narrowwinged Damselfly 5
Limnodrilus Worm 4
Physa Air-Breathing Freshwater Snail 2
Ancyronyx Spider Riffle Beetle 2
Stenochironomus European Non-Biting Midge 2
Berosus 2
Polypedilum Non-Biting Midges 2
Thienemannimyia Non-Biting Midges 1
Ablabesmyia Non-Biting Midge 1
Brillia Non-Biting Midges 1
Conchapelopia Non-Biting Midges 1
Macromia 1
Simuliidae Black Fly 1
Prostoma Freshwater Nemertean (Ribbon Worm) 1
Eurylophella Mayfly 1
Lumbriculidae Worm 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.