MBSS Site Summary for: PG-N-257-306-97


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 Good - 4.0 / 5.0
Benthic IBI Poor - 1.6 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 9,474 acres A highly channelized urban stream with concrete banks. An example of a highly channelized urban stream.
Urban Land Use 55.4 %
Agricultural Land Use 11.5 %
Forested Land Use 30 %


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 14/20 (Suboptimal)
Pool Quality
Pool Extent = meters 		17/20 (Optimal)
Riffle Quality 16/20 (Optimal)
Shading 85 %
Embeddedness 35 %
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) 7.44
Conductivity 280 µmho/cm
Alkalinity
(acid neutralizing capacity) 		758.2 µeq/L
Dissolved organic carbon (DOC) 3 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 13 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Swallowtail Shiner 138
Blacknose Dace 94
Tessellated Darter 82
American Eel 47
Creek Chub 38
Redbreast Sunfish 38
Longnose Dace 25
Satinfin Shiner 12
Mummichog 4
Creek Chubsucker 3
White Sucker 3
Pumpkinseed 2
Rosyside Dace 2
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Northern Green Frog
Northern Two-Lined Salamander

Crayfish:
Orconectes limosus

Exotic Plants:
No exotic plants noted.
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Cricotopus/Orthocladius Midge 39
Rheocricotopus Non-Biting Midges 27
Cricotopus Non-Biting Midges 13
Rheotanytarsus Non-Biting Midges 5
Lumbriculidae Worm 4
Hydropsyche Net-Spinning Caddisfly 2
Naididae Aquatic Worm 2
Tipula Crane Fly 1
Ormosia Cranefly 1
Prostoma Freshwater Nemertean (Ribbon Worm) 1
Conchapelopia Non-Biting Midges 1
Dicrotendipes Non-Biting Midges 1
Boyeria Spotted Darner Dragonfly 1
Hemerodromia Tiny Fly 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.