MBSS Site Summary for: PAXU-117-R-2004

Site Photos

Field photo showing stream conditions at site PAXU-117-R-2004-57 (Opens in a new window) Field photo showing stream conditions at site PAXU-117-R-2004-58 (Opens in a new window) Field photo showing stream conditions at site PAXU-117-R-2004-59 (Opens in a new window)

Located on HORSEPEN BR UT in the Patuxent River upper watershed, 8-digit code: 02131104.
This stream was visited in the spring on 3/9/2004 and again in the summer on 6/10/2004.

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 - 1.3 / 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 483 acres A highly channelized urban stream with concrete banks. An example of a highly channelized urban stream.
Urban Land Use 49 %
Agricultural Land Use 16 %
Forested Land Use 34 %


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

Physical Stream Habitat
Instream Habitat 9/20 (Marginal)
Epifaunal Substrate 6/20 (Marginal)
Velocity/Depth Diversity 6/20 (Marginal)
Pool Quality
Pool Extent = 59 meters 		8/20 (Marginal)
Riffle Quality
Riffle Extent = 19 meters 		6/20 (Marginal)
Shading 95 %
Embeddedness 40 %


Stream Water Quality:
Water temperature 20 ° C
Dissolved oxygen (DO) 6.5 mg/L
pH (lab) 6.74
Conductivity 282 µmho/cm
Alkalinity
(acid neutralizing capacity) 		503.8 µeq/L
Dissolved organic carbon (DOC) 1.2 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 2 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Blacknose Dace 93
American Eel 2
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Eastern Box Turtle
Gray Treefrog
Northern Green Frog
Northern Two-Lined Salamander

Crayfish:
No crayfish noted.

Exotic Plants:
Japanese Honeysuckle
Japanese Stiltgrass
Multiflora Rose
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Lumbriculidae Worm 10
Thienemannimyia group Non-Biting Midges 8
Tubificidae Aquatic Worm 6
Tipula Crane Fly 4
Cheumatopsyche Net-Spinning Caddisfly 4
Brillia Non-Biting Midges 4
Limnodrilus Worm 4
Parametriocnemus Non-Biting Midges 2
Polypedilum Non-Biting Midges 2
Conchapelopia Non-Biting Midges 2
Eukiefferiella Non-Biting Midges 1
Orthocladius Non-Biting Midges 1
Stenochironomus European Non-Biting Midge 1
Caecidotea Isopod 1
Dineutus Whirlygig Beetle 1
Enchytraeidae Aquatic 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.