MBSS Site Summary for: PAXL-294-S-2010

Site Photos

Field photo showing stream conditions at site PAXL-294-S-2010-1 (Opens in a new window) Field photo showing stream conditions at site PAXL-294-S-2010-2 (Opens in a new window)

Located on Swanson Creek in the Patuxent River lower watershed, 8-digit code: 02131101.
This stream was visited in the spring on 4/18/2010 and again in the summer on 7/14/2010.

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 - 4.7 / 5.0
Benthic IBI Good - 5.0 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 3,723 acres A stream flowing through a densely forested area. An example of a forested stream.
Urban Land Use 3.6 %
Agricultural Land Use 30.9 %
Forested Land Use 62.6 %


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 14/20 (Suboptimal)
Pool Quality
Pool Extent = 65 meters 		15/20 (Suboptimal)
Riffle Quality
Riffle Extent = 15 meters 		12/20 (Suboptimal)
Shading 90 %
Embeddedness 75 %
The embeddedness, a measure of silt on the stream bottom, was 75%. This is relatively high, and may exclude some biota.


Stream Water Quality:
pH (lab) 6.96
Alkalinity
(acid neutralizing capacity) 		158.4 µeq/L
Dissolved organic carbon (DOC) 2.67 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 11 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Fallfish 65
Blacknose Dace 44
Rosyside Dace 36
Creek Chubsucker 10
Eastern Mudminnow 8
Tessellated Darter 6
Sea Lamprey 5
American Eel 4
White Sucker 4
Tadpole Madtom 2
Least Brook Lamprey 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
Haploperla Green Stonefly 25
Ephemerella Sulphur Mayfly 22
Acerpenna Tiny Blue-Winged Olive Mayflies 11
Amphinemura Spring Stonefly 8
Polypedilum Non-Biting Midges 8
Orthocladius Non-Biting Midges 6
Simulium Black Fly 5
Baetidae Small Minnow Mayfly 4
Hexatoma Crane Fly 2
Ironoquia Northern Caddisfly 2
Oulimnius Riffle Beetle 2
Amphipoda Scud 1
Elmidae Riffle Beetle 1
Pycnopsyche Great Autumn Brown Sedge Caddisfly 1
Thienemannimyia Group Non-Biting Midges 1
Zavrelimyia Non-Biting Midges 1
Neophylax Caddisfly 1
Stenelmis Beetle 1
Probezzia Biting Midges 1
Lepidostoma Little Brown Sedge Caddisfly 1
Cheumatopsyche Net-Spinning Caddisfly 1
Hydropsyche Net-Spinning Caddisfly 1
Micropsectra Non-Biting Midges 1
Ephemerellidae Spiny Crawler Mayfly 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.