MBSS Site Summary for: PAXL-294-S-2011


Located on SWANSON CREEK in the Patuxent River lower watershed, 8-digit code: 02131101.
This stream was visited in the spring on 3/28/2011 and again in the summer on 6/28/2011.

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 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 18/20 (Optimal)
Epifaunal Substrate 15/20 (Suboptimal)
Velocity/Depth Diversity 16/20 (Optimal)
Pool Quality
Pool Extent = 42 meters 		17/20 (Optimal)
Riffle Quality
Riffle Extent = 36 meters 		15/20 (Suboptimal)
Shading 85 %
Embeddedness 40 %
Several measures of instream habitat were considered 'Optimal' at this location.


Stream Water Quality:
pH (lab) 6.965
Alkalinity
(acid neutralizing capacity) 		169.1 µeq/L
Dissolved organic carbon (DOC) 2.6909 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 12 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Blacknose Dace 119
Fallfish 116
Rosyside Dace 86
Tessellated Darter 35
Eastern Mudminnow 15
White Sucker 11
Least Brook Lamprey 7
Sea Lamprey 7
American Eel 6
Creek Chubsucker 4
Tadpole Madtom 3
Redbreast Sunfish 2
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Northern Green Frog

Crayfish:
Orconectes limosus

Exotic Plants:
Japanese Stiltgrass
Mile-A-Minute
Multiflora Rose
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Acerpenna Tiny Blue-Winged Olive Mayflies 17
Micropsectra Non-Biting Midges 14
CHLOROPERLIDAE Green Stonefly 10
Cheumatopsyche Net-Spinning Caddisfly 9
Ephemerella Sulphur Mayfly 7
Neophylax Caddisfly 5
PERLIDAE Common Stonefly 5
Strophopteryx Early Brown Stonefly 4
Isoperla Stripetail Stonefly 3
Oulimnius Riffle Beetle 3
Parametriocnemus Non-Biting Midges 3
CERATOPOGONIDAE Biting Midge 3
Rheocricotopus Non-Biting Midges 3
Rheotanytarsus Non-Biting Midges 2
Stempellinella Non-Biting Midges 2
Simulium Black Fly 2
Microtendipes Non-Biting Midges 2
Thienemannimyia Group Non-Biting Midges 2
Zavrelimyia Non-Biting Midges 2
Ablabesmyia Non-Biting Midge 2
Corynoneura Non-Biting Midges 1
Eukiefferiella Non-Biting Midges 1
LEPTOCERIDAE Longhorned Casemaker Caddisfly 1
Maccaffertium March Brown And Cahill Mayfly 1
Eurylophella Mayfly 1
Nigronia Megaloptera (Dark Fishfly) 1
Tipula Crane Fly 1
TIPULIDAE Cranefly 1
Sialis Alderfly 1
TUBIFICIDAE Aquatic Worm 1
Anchytarsus Beetle 1
Stenelmis Beetle 1
Optioservus Riffle Beetle 1
Paraphaenocladius Non-Biting Midges 1
CRANGONYCTIDAE Scud 1
Nanocladius Non-Biting Midges 1
Tanypodinae 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.