MBSS Site Summary for: AA-N-152-318-97


Located on DORSEY RUN in the Little Patuxent River watershed, 8-digit code: 02131105.
This stream was visited in the spring on 4/2/1997 and again in the summer on 7/14/1997.

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 - 3.3 / 5.0
Benthic IBI Poor - 1.3 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 7,814 acres A highly channelized urban stream with concrete banks. An example of a highly channelized urban stream.
Urban Land Use 33.8 %
Agricultural Land Use 21.2 %
Forested Land Use 36.9 %


Stream showing woody debris, logs, and rocky substrate.
An example of woody debris in a stream.

Physical Stream Habitat
Instream Habitat 13/20 (Suboptimal)
Epifaunal Substrate 14/20 (Suboptimal)
Velocity/Depth Diversity 14/20 (Suboptimal)
Pool Quality
Pool Extent = meters 		18/20 (Optimal)
Riffle Quality 11/20 (Suboptimal)
Shading 80 %
Embeddedness 25 %


Stream Water Quality:
Water temperature 22.6 ° C
Dissolved oxygen (DO) 6.8 mg/L
pH (lab) 7.68
Conductivity 382 µmho/cm
Alkalinity
(acid neutralizing capacity) 		1112 µeq/L
Dissolved organic carbon (DOC) 3.6 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 16 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Swallowtail Shiner 62
Fallfish 50
White Sucker 31
Tessellated Darter 15
Common Shiner 12
Satinfin Shiner 9
Longnose Dace 8
Redbreast Sunfish 6
Eastern Mudminnow 5
Sea Lamprey 4
American Eel 3
Bluegill 2
Pumpkinseed 2
Redfin Pickerel 2
Yellow Perch 2
Smallmouth Bass 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Eastern Box Turtle
Northern Green Frog
Northern Spring Peeper
Pickerel Frog

Crayfish:
No crayfish noted.

Exotic Plants:
No exotic plants noted.
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Orthocladiinae A Non-Biting Midges 31
Cricotopus/Orthocladius Midge 24
Rheocricotopus Non-Biting Midges 6
Saetheria 2
Simuliidae Black Fly 1
Simulium Black Fly 1
Diamesa Bloodworm 1
Rheotanytarsus Non-Biting Midges 1
Ancyronyx Spider Riffle Beetle 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.