MBSS Site Summary for: PAXL-294-S-2009

Site Photos

Field photo showing stream conditions at site PAXL-294-S-2009-1 (Opens in a new window) Field photo showing stream conditions at site PAXL-294-S-2009-2 (Opens in a new window)

Located on Swanson Creek in the Patuxent River lower watershed, 8-digit code: 02131101.
This stream was visited in the spring on 4/1/2009 and again in the summer on 6/16/2009.

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 - 4.1 / 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 17/20 (Optimal)
Epifaunal Substrate 15/20 (Suboptimal)
Velocity/Depth Diversity 16/20 (Optimal)
Pool Quality
Pool Extent = 62 meters 		17/20 (Optimal)
Riffle Quality
Riffle Extent = 37 meters 		17/20 (Optimal)
Shading 80 %
Embeddedness 75 %
The embeddedness, a measure of silt on the stream bottom, was 75%. 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 18.6 ° C
Dissolved oxygen (DO) 8.9 mg/L
pH (lab) 7.09
Conductivity 108 µmho/cm
Alkalinity
(acid neutralizing capacity) 		235.6 µeq/L
Dissolved organic carbon (DOC) 2.4938 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 10 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Blacknose Dace 56
Fallfish 41
Rosyside Dace 26
Creek Chubsucker 12
Tessellated Darter 11
Sea Lamprey 9
American Eel 7
Eastern Mudminnow 4
Least Brook Lamprey 2
Tadpole Madtom 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Eastern Cricket Frog
Northern Green Frog
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
Cricotopus Non-Biting Midges 23
Acerpenna Tiny Blue-Winged Olive Mayflies 17
Haploperla Green Stonefly 13
Ephemerella Sulphur Mayfly 12
Orthocladius Non-Biting Midges 11
Ephemerellidae Spiny Crawler Mayfly 5
Oulimnius Riffle Beetle 4
Baetidae Small Minnow Mayfly 4
Tvetenia Non-Biting Midges 3
Parametriocnemus Non-Biting Midges 3
Tanytarsini Non-Biting Midges 2
Hexatoma Crane Fly 2
Cheumatopsyche Net-Spinning Caddisfly 2
Amphinemura Spring Stonefly 2
Hemerodromia Tiny Fly 2
Lumbriculidae Worm 2
Hydropsyche Net-Spinning Caddisfly 1
Brillia Non-Biting Midges 1
Maccaffertium March Brown And Cahill Mayfly 1
Nemouridae Nemourid Stonefly 1
Naididae Aquatic Worm 1
Ceratopogonidae Biting Midge 1
Hydropsychidae Common Netspinner Caddisfly 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.