MBSS Site Summary for: RKGR-119-S-2012


Located on PATUXENT RIVER UT in the Rocky Gorge Dam watershed, 8-digit code: 02131107.
This stream was visited in the spring on 4/2/2012 and again in the summer on 7/2/2012.

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 - 5.0 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 673 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 4.5 %
Agricultural Land Use 58.3 %
Forested Land Use 34.8 %


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

Physical Stream Habitat
Instream Habitat 13/20 (Suboptimal)
Epifaunal Substrate 15/20 (Suboptimal)
Velocity/Depth Diversity 11/20 (Suboptimal)
Pool Quality
Pool Extent = 50 meters 		16/20 (Optimal)
Riffle Quality
Riffle Extent = 39 meters 		11/20 (Suboptimal)
Shading 90 %
Embeddedness 15 %


Stream Water Quality:
pH (lab) 7.94
Alkalinity
(acid neutralizing capacity) 		1156.5 µeq/L
Dissolved organic carbon (DOC) 0.9603 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 12 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Blue Ridge Sculpin 92
Blacknose Dace 23
Largemouth Bass 23
Creek Chub 11
Fallfish 10
Rosyside Dace 7
Longnose Dace 6
Bluegill 4
Tessellated Darter 2
White Sucker 2
Green Sunfish 1
Yellow Bullhead 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Eastern American Toad
Northern Green Frog

Crayfish:
Cambarus bartonii bartonii
Orconectes virilis

Exotic Plants:
Autumn Olive
Garlic Mustard
Japanese Barberry
Japanese Honeysuckle
Japanese Stiltgrass
Multiflora Rose
Oriental Bittersweet
Wineberry
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Ephemerella Sulphur Mayfly 24
Amphinemura Spring Stonefly 20
Simulium Black Fly 18
EPHEMERELLIDAE Spiny Crawler Mayfly 13
Orthocladius Non-Biting Midges 9
Nigronia Megaloptera (Dark Fishfly) 5
Prosimulium Black Fly 4
Dolophilodes Medium Evening Sedge Caddisfly 4
Isoperla Stripetail Stonefly 3
Orthocladiinae Midge 3
Hydropsyche Net-Spinning Caddisfly 3
Cricotopus Non-Biting Midges 2
SIMULIIDAE Black Fly 2
EMPIDIDAE Dance Fly 2
Optioservus Riffle Beetle 2
Polypedilum Non-Biting Midges 2
Tanytarsus Non-Biting Midges 1
Thienemannimyia Group Non-Biting Midges 1
Acentrella Tiny Blue-Winged Olive Mayflies 1
Rhyacophila Free-Living Caddisfly 1
Acroneuria Golden Stoneflies 1
Maccaffertium March Brown And Cahill Mayfly 1
Leuctra  Rolled-Winged Stonefly 1
NAIDIDAE Aquatic Worm 1
Diplectrona Net-Spinning Caddisfly 1
Hydrobaenus Midge 1
Diamesa Bloodworm 1
Ameletus Combmouthed Minnow Mayfly 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.