MBSS Site Summary for: RKGR-119-S-2003

Site Photos

Field photo showing stream conditions at site RKGR-119-S-2003-761 (Opens in a new window)

Located on PATUXENT R UT2 in the Rocky Gorge Dam watershed, 8-digit code: 02131107.
This stream was visited in the spring on 4/3/2003 and again in the summer on 7/22/2003.

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 - 3.7 / 5.0
Benthic IBI Good - 4.3 / 5.0

Land Use

Land use can provide important information for determining stream health.
(Hint: Screen readers will announce definitions; mouse users can hover over dotted text.)
Catchment area 670 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 4.6 %
Agricultural Land Use 58.1 %
Forested Land Use 35 %


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

Physical Stream Habitat
Instream Habitat 18/20 (Optimal)
Epifaunal Substrate 18/20 (Optimal)
Velocity/Depth Diversity 14/20 (Suboptimal)
Pool Quality
Pool Extent = 29 meters 		14/20 (Suboptimal)
Riffle Quality
Riffle Extent = 56 meters 		16/20 (Optimal)
Shading 93 %
Embeddedness 10 %
Several measures of instream habitat were considered 'Optimal' at this location.


Stream Water Quality:
Water temperature 18.9 ° C
Dissolved oxygen (DO) 7.9 mg/L
pH (lab) 7.56
Conductivity 175 µmho/cm
Alkalinity
(acid neutralizing capacity) 		877.9 µeq/L
Dissolved organic carbon (DOC) 1.3 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 160
Blue Ridge Sculpin 87
Rosyside Dace 40
Creek Chub 9
Bluegill 5
Longnose Dace 3
Green Sunfish 2
White Sucker 2
Fallfish 1
Largemouth Bass 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Eastern American Toad
Northern Red Salamander
Northern Two-Lined Salamander

Crayfish:
No crayfish noted.

Exotic Plants:
Japanese Honeysuckle
Japanese Stiltgrass
Multiflora Rose
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Prosimulium Black Fly 53
Ephemerella Sulphur Mayfly 33
Neophylax Caddisfly 9
Amphinemura Spring Stonefly 6
Naididae Aquatic Worm 3
Simuliidae Black Fly 2
Cheumatopsyche Net-Spinning Caddisfly 2
Diplectrona Net-Spinning Caddisfly 1
Brillia Non-Biting Midges 1
Eukiefferiella Non-Biting Midges 1
Orthocladius Non-Biting Midges 1
Parametriocnemus Non-Biting Midges 1
Potthastia Non-Biting Midges 1
Tanytarsini Non-Biting Midges 1
Antocha Crane Fly 1
Pseudolimnophila Crane Fly 1
Stenonema Flatheaded Mayfly 1
Rhyacophila Free-Living Caddisfly 1
Girardia Freshwater Flatworm 1
Gordiidae Horsehair Worm 1
Nigronia Megaloptera (Dark Fishfly) 1
Simulium Black Fly 1
Diamesa Bloodworm 1
Stenelmis Beetle 1
Ostrocerca Stonefly 1
Chelifera Aquatic Dance Fly 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.