MBSS Site Summary for: PAXM-218-X-2006


Located on Swan Point Creek in the Patuxent River middle watershed, 8-digit code: 02131102.
This stream was visited in the spring on 3/21/2006 and again in the summer on 7/5/2006.

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 - 4.3 / 5.0
Benthic IBI Poor - 2.1 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 1,063 acres A stream flowing through a densely forested area. An example of a forested stream.
Urban Land Use 1 %
Agricultural Land Use 36 %
Forested Land Use 63 %


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

Physical Stream Habitat
Instream Habitat 15/20 (Suboptimal)
Epifaunal Substrate 13/20 (Suboptimal)
Velocity/Depth Diversity 10/20 (Marginal)
Pool Quality
Pool Extent = 44 meters 		10/20 (Marginal)
Riffle Quality
Riffle Extent = 38 meters 		17/20 (Optimal)
Shading 90 %
Embeddedness 80 %
The embeddedness, a measure of silt on the stream bottom, was 80%. This is relatively high, and may exclude some biota.


Stream Water Quality:
Water temperature 22.1 ° C
Dissolved oxygen (DO) 6.5 mg/L
pH (lab) 6.85
Conductivity 158 µmho/cm
Alkalinity
(acid neutralizing capacity) 		227.2 µeq/L
Dissolved organic carbon (DOC) 2.4432 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 10 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Eastern Mudminnow 32
Blacknose Dace 28
Green Sunfish 11
Creek Chubsucker 9
Bluegill 6
American Eel 4
Golden Shiner 4
Brown Bullhead 1
Least Brook Lamprey 1
Pumpkinseed 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Northern Green Frog

Crayfish:
Orconectes limosus

Exotic Plants:
Japanese Stiltgrass
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Orthocladius Non-Biting Midges 77
Hydrobaenus Midge 13
Stegopterna Black Fly 5
Diplocladius Non-Biting Midges 4
Gammarus Amphipod 4
Zavrelimyia Non-Biting Midges 2
Pisidiidae Pill Clam 1
Dubiraphia Riffle Beetle 1
Paracapnia Small Winter Stonefly 1
Lumbriculidae Worm 1
Enchytraeidae Aquatic Worm 1
Ceratopogonidae Biting Midge 1
Prosimulium Black Fly 1
Simulium Black Fly 1
Paraphaenocladius Non-Biting Midges 1
Polypedilum Non-Biting Midges 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.