MBSS Site Summary for: AA-N-021-112-97


Located on STOCKETT'S RUN in the Patuxent River upper watershed, 8-digit code: 02131104.
This stream was visited in the spring on 3/6/1997 and again in the summer on 6/30/1997.

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 Fair - 3.0 / 5.0
Benthic IBI Fair - 3.3 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 1,487 acres Cows standing in a stream at a site with high agricultural land use. Cows survey the sampling procedure at this extreme example of a highly agriculturalized site.
Urban Land Use 1.2 %
Agricultural Land Use 51.3 %
Forested Land Use 47.5 %


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 13/20 (Suboptimal)
Pool Quality
Pool Extent = meters 		12/20 (Suboptimal)
Riffle Quality 11/20 (Suboptimal)
Shading 80 %
Embeddedness 35 %


Stream Water Quality:
Water temperature 20.1 ° C
Dissolved oxygen (DO) 8.4 mg/L
pH (lab) 6.69
Conductivity 184 µmho/cm
Alkalinity
(acid neutralizing capacity) 		253.2 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 8 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Blacknose Dace 255
Tessellated Darter 28
Swallowtail Shiner 17
White Sucker 13
American Eel 9
Least Brook Lamprey 8
Rosyside Dace 8
Green Sunfish 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Eastern American Toad
Northern Two-Lined Salamander
Southern Leopard Frog

Crayfish:
Orconectes limosus

Exotic Plants:
No exotic plants noted.
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Orthocladiinae A Non-Biting Midges 39
Cricotopus/Orthocladius Midge 22
Crangonyx Amphipod 9
Eukiefferiella Non-Biting Midges 8
Neophylax Caddisfly 5
Prosimulium Black Fly 4
Tubificidae Aquatic Worm 3
Parametriocnemus Non-Biting Midges 3
Acerpenna Tiny Blue-Winged Olive Mayflies 3
Polypedilum Non-Biting Midges 2
Limnephilidae Northern Casemaker Caddisfly 2
Stygobromus Amphipod 2
Tipula Crane Fly 1
Tipulidae Cranefly 1
Dicranota Hairy-Eyed Cranefly 1
Allocapnia Small Winter Stonefly 1
Boyeria Spotted Darner Dragonfly 1
Amphinemura Spring Stonefly 1
Prostoia Spring Stonefly 1
Oemopteryx Stonefly 1
Isoperla Stripetail Stonefly 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.