MBSS Site Summary for: CH-S-231-202-97


Located on SWANSON CR in the Patuxent River lower watershed, 8-digit code: 02131101.
This stream was visited in the spring on 3/11/1997 and again in the summer on 8/1/1997.

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 - 4.4 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 5,480 acres A stream flowing through a densely forested area. An example of a forested stream.
Urban Land Use 7.7 %
Agricultural Land Use 20.8 %
Forested Land Use 68.8 %


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 12/20 (Suboptimal)
Velocity/Depth Diversity 11/20 (Suboptimal)
Pool Quality
Pool Extent = meters 		12/20 (Suboptimal)
Riffle Quality 12/20 (Suboptimal)
Shading 93 %
Embeddedness 20 %


Stream Water Quality:
Water temperature 19.4 ° C
Dissolved oxygen (DO) 9.6 mg/L
pH (lab) 6.82
Conductivity 96 µmho/cm
Alkalinity
(acid neutralizing capacity) 		156 µeq/L
Dissolved organic carbon (DOC) 2.6 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 13 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Blacknose Dace 130
Rosyside Dace 105
Fallfish 67
Least Brook Lamprey 58
Tessellated Darter 36
Eastern Mudminnow 13
Sea Lamprey 11
Tadpole Madtom 7
American Eel 5
White Sucker 4
Redfin Pickerel 3
Creek Chubsucker 1
Redbreast Sunfish 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Eastern Cricket Frog
Northern Green Frog
Northern Two-Lined Salamander
Pickerel Frog

Crayfish:
Orconectes limosus

Exotic Plants:
No exotic plants noted.
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Acerpenna Tiny Blue-Winged Olive Mayflies 36
Ephemerella Sulphur Mayfly 17
Optioservus Riffle Beetle 8
Prostoia Spring Stonefly 7
Neophylax Caddisfly 4
Antocha Crane Fly 3
Hexatoma Crane Fly 3
Tvetenia Non-Biting Midges 3
Cheumatopsyche Net-Spinning Caddisfly 3
Stictochironomus Non-Biting Midge 3
Gammarus Amphipod 2
Naididae Aquatic Worm 2
Hemerodromia Tiny Fly 2
Helichus Beetle 1
Prosimulium Black Fly 1
Simulium Black Fly 1
Nigronia Megaloptera (Dark Fishfly) 1
Cricotopus/Orthocladius Midge 1
Microtendipes Non-Biting Midges 1
Rheotanytarsus Non-Biting Midges 1
Paracladopelma Non-Biting Midge 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.