MBSS Site Summary for: CH-S-231-209-97


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 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 - 5.0 / 5.0

Land Use

Land use can provide important information for determining stream health.
(Hint: Screen readers will announce definitions; mouse users can hover over dotted text.)
Catchment area 3,791 acres A stream flowing through a densely forested area. An example of a forested stream.
Urban Land Use 8.6 %
Agricultural Land Use 22.7 %
Forested Land Use 64.8 %


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

Physical Stream Habitat
Instream Habitat 10/20 (Marginal)
Epifaunal Substrate 9/20 (Marginal)
Velocity/Depth Diversity 13/20 (Suboptimal)
Pool Quality
Pool Extent = meters 		13/20 (Suboptimal)
Riffle Quality 11/20 (Suboptimal)
Shading 60 %
Embeddedness 40 %


Stream Water Quality:
Water temperature 19.2 ° C
Dissolved oxygen (DO) 7.7 mg/L
pH (lab) 6.29
Conductivity 76 µmho/cm
Alkalinity
(acid neutralizing capacity) 		54.2 µeq/L
Dissolved organic carbon (DOC) 3.2 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
Rosyside Dace 225
Blacknose Dace 154
Least Brook Lamprey 109
Fallfish 50
Tessellated Darter 37
Eastern Mudminnow 23
Tadpole Madtom 12
American Eel 7
Creek Chubsucker 6
Redbreast Sunfish 4
White Sucker 3
Bluegill 1
Sea Lamprey 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Eastern Snapping Turtle
Northern Green Frog
Northern Spring Peeper
Northern Two-Lined Salamander

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 20
Tanytarsus Non-Biting Midges 15
Sweltsa Stonefly 13
Acerpenna Tiny Blue-Winged Olive Mayflies 10
Cricotopus/Orthocladius Midge 10
Hexatoma Crane Fly 4
Oulimnius Riffle Beetle 4
Amphinemura Spring Stonefly 3
Optioservus Riffle Beetle 3
Polypedilum Non-Biting Midges 2
Tvetenia Non-Biting Midges 2
Prostoma Freshwater Nemertean (Ribbon Worm) 2
Eurylophella Mayfly 2
Prostoia Spring Stonefly 2
Ancyronyx Spider Riffle Beetle 2
Ephemerella Sulphur Mayfly 2
Lumbriculidae Worm 1
Leuctra  Rolled-Winged Stonefly 1
Chelifera Aquatic Dance Fly 1
Helichus Beetle 1
Probezzia Biting Midges 1
Lype Net Tube Caddisfly 1
Cheumatopsyche Net-Spinning Caddisfly 1
Parametriocnemus 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.