MBSS Site Summary for: PAXL-294-S-2006


Located on Swanson Creek in the Patuxent River lower watershed, 8-digit code: 02131101.
This stream was visited in the spring on 3/15/2006 and again in the summer on 7/18/2006.

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 - 4.7 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 3,717 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 16/20 (Optimal)
Epifaunal Substrate 12/20 (Suboptimal)
Velocity/Depth Diversity 12/20 (Suboptimal)
Pool Quality
Pool Extent = 51 meters 		16/20 (Optimal)
Riffle Quality
Riffle Extent = 35 meters 		16/20 (Optimal)
Shading 90 %
Embeddedness 65 %
The embeddedness, a measure of silt on the stream bottom, was 65%. This is relatively high, and may exclude some biota.
Several measures of instream habitat were considered 'Optimal' at this location.


Stream Water Quality:
Water temperature 24.4 ° C
Dissolved oxygen (DO) 7.6 mg/L
pH (lab) 7.11
Conductivity 102 µmho/cm
Alkalinity
(acid neutralizing capacity) 		193.3 µeq/L
Dissolved organic carbon (DOC) 2.5268 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 14 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Blacknose Dace 34
Sea Lamprey 22
Tessellated Darter 12
American Eel 11
Eastern Mudminnow 8
Creek Chubsucker 5
Rosyside Dace 5
Largemouth Bass 3
Least Brook Lamprey 2
Pumpkinseed 2
Tadpole Madtom 2
Fallfish 1
Redfin Pickerel 1
White Sucker 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Northern Two-Lined Salamander

Crayfish:
Orconectes limosus

Exotic Plants:
Japanese Honeysuckle
Japanese Stiltgrass
Multiflora Rose
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Ephemerella Sulphur Mayfly 21
Oulimnius Riffle Beetle 20
Haploperla Green Stonefly 13
Prosimulium Black Fly 7
Acerpenna Tiny Blue-Winged Olive Mayflies 7
Isoperla Stripetail Stonefly 6
Prostoia Spring Stonefly 5
Amphinemura Spring Stonefly 4
Optioservus Riffle Beetle 4
Perlodidae Perlodid Stonefly 3
Neophylax Caddisfly 3
Hexatoma Crane Fly 3
Cheumatopsyche Net-Spinning Caddisfly 3
Rheocricotopus Non-Biting Midges 2
Rheosmittia Non-Biting Midges 2
Stenonema Flatheaded Mayfly 2
Gomphidae Clubtail Dragonfly 1
Simulium Black Fly 1
Gammarus Amphipod 1
Stenelmis Beetle 1
Tanytarsus Non-Biting Midges 1
Trissopelopia Non-Biting Midges 1
Microtendipes Non-Biting Midges 1
Polypedilum Non-Biting Midges 1
Nigronia Megaloptera (Dark Fishfly) 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.