MBSS Site Summary for: RKGR-405-R-2002

Site Photos

Field photo showing stream conditions at site RKGR-405-R-2002-1 (Opens in a new window) Field photo showing stream conditions at site RKGR-405-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 Fair - 3.3 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 71,318 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 31 %


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 8/20 (Marginal)
Velocity/Depth Diversity 10/20 (Marginal)
Pool Quality
Pool Extent = 75 meters 		18/20 (Optimal)
Riffle Quality
Riffle Extent = 0 meters 		0/20 (Poor)
Shading 80 %
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 22.9 ° C
Dissolved oxygen (DO) 5.3 mg/L
pH (lab) 7.35
Conductivity 160 µmho/cm
Alkalinity
(acid neutralizing capacity) 		523.2 µeq/L
Dissolved organic carbon (DOC) 2.5 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 11 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Gizzard Shad 44
Bluegill 33
Largemouth Bass 27
Tessellated Darter 19
White Sucker 9
Spotfin Shiner 6
Fallfish 2
White Perch 2
Northern Hogsucker 1
Redbreast Sunfish 1
Yellow Perch 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Eastern American Toad
Northern Green Frog
Pickerel Frog

Crayfish:
No crayfish noted.

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

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Stenonema Flatheaded Mayfly 10
Cricotopus Non-Biting Midges 10
Tanytarsus Non-Biting Midges 10
Orthocladius Non-Biting Midges 9
Rheosmittia Non-Biting Midges 6
Ablabesmyia Non-Biting Midge 5
Crangonyx Amphipod 5
Lype Net Tube Caddisfly 4
Nanocladius Non-Biting Midges 4
Tribelos Non-Biting Midges 4
Ancyronyx Spider Riffle Beetle 3
Thienemannimyia Non-Biting Midges 3
Microtendipes Non-Biting Midges 3
Stilobezzia 3
Paralauterborniella 2
Procloeon 2
Sphaerium Fingernail Clam 2
Cheumatopsyche Net-Spinning Caddisfly 2
Corynoneura Non-Biting Midges 2
Tanypodinae Non-Biting Midges 2
Thienemanniella Non-Biting Midges 2
Hydroporus Water Beetle 2
Polycentropus Tube Maker Caddisfly 1
Leptophlebiidae Pronggilled Mayfly 1
Optioservus Riffle Beetle 1
Ferrissia Small Air-Breathing Freshwater Limpets 1
Procladius Non-Biting Midge 1
Stenacron Mayfly 1
Xylotopus Midge 1
Nemouridae Nemourid Stonefly 1
Glyptotendipes 1
Stylogomphus Clubtail Dragonfly 1
Antocha Crane Fly 1
Physa Air-Breathing Freshwater Snail 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.