MBSS Site Summary for: PAXU-101-R-2008

Site Photos

Field photo showing stream conditions at site PAXU-101-R-2008-1 (Opens in a new window) Field photo showing stream conditions at site PAXU-101-R-2008-2 (Opens in a new window)

Located on MT. NEBO BRANCH in the Patuxent River upper watershed, 8-digit code: 02131104.
This stream was visited in the spring on 3/25/2008 and again in the summer on 6/20/2008.

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 - 2.3 / 5.0
Benthic IBI Poor - 2.7 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 1,190 acres A stream flowing through a densely forested area. An example of a forested stream.
Urban Land Use 14.7 %
Agricultural Land Use 38 %
Forested Land Use 46.7 %


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

Physical Stream Habitat
Instream Habitat 6/20 (Marginal)
Epifaunal Substrate 5/20 (Poor)
Velocity/Depth Diversity 7/20 (Marginal)
Pool Quality
Pool Extent = 47 meters 		7/20 (Marginal)
Riffle Quality
Riffle Extent = 34 meters 		11/20 (Suboptimal)
Shading 90 %
Embeddedness 100 %
The embeddedness, a measure of silt on the stream bottom, was 100%. This is very high, and may adversely affect biotic communities.


Stream Water Quality:
Water temperature 15.4 ° C
Dissolved oxygen (DO) 8.6 mg/L
pH (lab) 7.52
Conductivity 368 µmho/cm
Alkalinity
(acid neutralizing capacity) 		1546.5 µeq/L
Dissolved organic carbon (DOC) 1.18 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 3 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Blacknose Dace 144
Tessellated Darter 34
American Eel 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

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

Crayfish:
No crayfish noted.

Exotic Plants:
Japanese Honeysuckle
Japanese Stiltgrass
Multiflora Rose
Oriental Bittersweet
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Gammarus Amphipod 29
Hydrobaenus Midge 13
Parametriocnemus Non-Biting Midges 10
Orthocladius Non-Biting Midges 9
Ceratopogonidae Biting Midge 7
Polypedilum Non-Biting Midges 6
Rheotanytarsus Non-Biting Midges 6
Paratendipes European Non-Biting Midge 4
Xylotopus Midge 3
Micropsectra Non-Biting Midges 3
Phaenopsectra Non-Biting Midges 2
Thienemannimyia Group Non-Biting Midges 2
Lype Net Tube Caddisfly 2
Procladius Non-Biting Midge 2
Probezzia Biting Midges 2
Tubificidae Aquatic Worm 2
Cryptotendipes 1
Paralauterborniella 1
Physa Air-Breathing Freshwater Snail 1
Tipulidae Cranefly 1
Musculium Fingernail Clam 1
Tabanidae Horse Fly 1
Corynoneura Non-Biting Midges 1
Cryptochironomus Non-Biting Midges 1
Diplocladius Non-Biting Midges 1
Paracladopelma Non-Biting Midge 1
Isotomidae Springtail 1
Limnodrilus Worm 1
Tanytarsus Non-Biting Midges 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.