MBSS Site Summary for: AA-N-152-304-97


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 - 3.7 / 5.0
Benthic IBI Poor - 1.0 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 7,729 acres A highly channelized urban stream with concrete banks. An example of a highly channelized urban stream.
Urban Land Use 33.9 %
Agricultural Land Use 21.3 %
Forested Land Use 36.8 %


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 10/20 (Marginal)
Velocity/Depth Diversity 11/20 (Suboptimal)
Pool Quality
Pool Extent = meters 		17/20 (Optimal)
Riffle Quality 5/20 (Poor)
Shading 72 %
Embeddedness 41 %


Stream Water Quality:
Water temperature 23.6 ° C
Dissolved oxygen (DO) 7.9 mg/L
pH (lab) 7.55
Conductivity 380 µmho/cm
Alkalinity
(acid neutralizing capacity) 		1109 µeq/L
Dissolved organic carbon (DOC) 3.9 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 19 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Fallfish 137
White Sucker 73
Tessellated Darter 53
Swallowtail Shiner 43
Redbreast Sunfish 25
Common Shiner 17
Satinfin Shiner 12
Eastern Mudminnow 11
American Eel 6
Redfin Pickerel 5
Bluegill 3
Longnose Dace 3
Creek Chub 2
Sea Lamprey 2
Yellow Perch 2
Blacknose Dace 1
Least Brook Lamprey 1
Pumpkinseed 1
Smallmouth Bass 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Eastern American Toad
Eastern Cricket Frog
Fowler's Toad
Gray Treefrog
Northern Green Frog
Pickerel Frog

Crayfish:
Orconectes virilis

Exotic Plants:
No exotic plants noted.
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Cricotopus/Orthocladius Midge 62
Orthocladiinae A Non-Biting Midges 41
Parametriocnemus Non-Biting Midges 1
Paratanytarsus Non-Biting Midges 1
Amphinemura Spring Stonefly 1
Cryptochironomus Non-Biting Midges 1
Saetheria 1
Hexatoma Crane 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.