MBSS Site Summary for: RKGR-409-R-2002

Site Photos

Field photo showing stream conditions at site RKGR-409-R-2002-1 (Opens in a new window) Field photo showing stream conditions at site RKGR-409-R-2002-2 (Opens in a new window)

Located on PATUXENT R in the Rocky Gorge Dam watershed, 8-digit code: 02131107.
This stream was visited in the spring on 3/19/2002 and again in the summer on 7/1/2002.

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 - 3.3 / 5.0
Benthic IBI Poor - 2.7 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 70,745 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 4 %
Agricultural Land Use 64 %
Forested Land Use 30 %


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 11/20 (Suboptimal)
Velocity/Depth Diversity 9/20 (Marginal)
Pool Quality
Pool Extent = 75 meters 		18/20 (Optimal)
Riffle Quality
Riffle Extent = 0 meters 		0/20 (Poor)
Shading 85 %
Embeddedness 90 %
The embeddedness, a measure of silt on the stream bottom, was 90%. This is relatively high, and may exclude some biota.


Stream Water Quality:
Water temperature 22.5 ° C
Dissolved oxygen (DO) 6 mg/L
pH (lab) 7.56
Conductivity 160 µmho/cm
Alkalinity
(acid neutralizing capacity) 		508.3 µeq/L
Dissolved organic carbon (DOC) 2.2 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
Bluegill 57
Tessellated Darter 51
Gizzard Shad 41
Yellow Perch 24
Largemouth Bass 21
Margined Madtom 9
White Sucker 8
Fallfish 7
Redbreast Sunfish 5
Green Sunfish 4
Spotfin Shiner 3
Satinfin Shiner 2
Shorthead Redhorse 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
No amphibians and reptiles noted.

Crayfish:
No crayfish noted.

Exotic Plants:
Japanese Honeysuckle
Japanese Stiltgrass
Mile-A-Minute
Multiflora Rose
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Rheosmittia Non-Biting Midges 18
Orthocladius Non-Biting Midges 17
Cricotopus Non-Biting Midges 13
Nanocladius Non-Biting Midges 10
Stenonema Flatheaded Mayfly 10
Rheocricotopus Non-Biting Midges 9
Conchapelopia Non-Biting Midges 5
Microtendipes Non-Biting Midges 3
Tubificidae Aquatic Worm 3
Thienemanniella Non-Biting Midges 3
Tribelos Non-Biting Midges 3
Tanytarsus Non-Biting Midges 2
Dineutus Whirlygig Beetle 2
Limnodrilus Worm 2
Orthocladiinae Midge 2
Cheumatopsyche Net-Spinning Caddisfly 2
Hydropsyche Net-Spinning Caddisfly 2
Corynoneura Non-Biting Midges 2
Dicrotendipes Non-Biting Midges 1
Ablabesmyia Non-Biting Midge 1
Lype Net Tube Caddisfly 1
Ceratopogonidae Biting Midge 1
Empididae Dance Fly 1
Pycnopsyche Great Autumn Brown Sedge Caddisfly 1
Stenacron Mayfly 1
Gyrinus Whirlygig Beetle 1
Ephemerella Sulphur Mayfly 1
Polycentropus Tube Maker 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.