MBSS Site Summary for: CH-S-091-131-97


Located on SWANSON CR UT1 in the Patuxent River lower watershed, 8-digit code: 02131101.
This stream was visited in the spring on 3/24/1997 and again in the summer on 7/7/1997.

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 1,237 acres A stream flowing through a densely forested area. An example of a forested stream.
Urban Land Use 10.5 %
Agricultural Land Use 15 %
Forested Land Use 74.6 %


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

Physical Stream Habitat
Instream Habitat 7/20 (Marginal)
Epifaunal Substrate 5/20 (Poor)
Velocity/Depth Diversity 11/20 (Suboptimal)
Pool Quality
Pool Extent = meters 		11/20 (Suboptimal)
Riffle Quality 11/20 (Suboptimal)
Shading 45 %
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 22.6 ° C
Dissolved oxygen (DO) 8.1 mg/L
pH (lab) 6.58
Conductivity 88 µmho/cm
Alkalinity
(acid neutralizing capacity) 		138.7 µeq/L
Dissolved organic carbon (DOC) 3.8 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
Least Brook Lamprey 372
Blacknose Dace 131
Tessellated Darter 90
Eastern Mudminnow 57
Rosyside Dace 52
Fallfish 37
Creek Chubsucker 19
Tadpole Madtom 15
Pumpkinseed 10
White Sucker 5
American Eel 4
Brown Bullhead 1
Golden Shiner 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Eastern Box Turtle
Northern Green Frog
Northern Spring Peeper
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
Prosimulium Black Fly 27
Cricotopus/Orthocladius Midge 8
Amphinemura Spring Stonefly 5
Bezzia Biting Midge 4
Chloroperlidae Green Stonefly 4
Eukiefferiella Non-Biting Midges 3
Parametriocnemus Non-Biting Midges 3
Rheotanytarsus Non-Biting Midges 3
Tanytarsus Non-Biting Midges 2
Hemerodromia Tiny Fly 2
Cheumatopsyche Net-Spinning Caddisfly 2
Calopteryx Damselfly 2
Siphlonurus Gray Drake Mayfly 1
Lype Net Tube Caddisfly 1
Hydropsyche Net-Spinning Caddisfly 1
Polypedilum Non-Biting Midges 1
Tabanidae Horse Fly 1
Lepidostoma Little Brown Sedge Caddisfly 1
Nigronia Megaloptera (Dark Fishfly) 1
Chelifera Aquatic Dance Fly 1
Tipula Crane Fly 1
Baetidae Small Minnow 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.