MBSS Site Summary for: ROCK-211-R-2003

Site Photos

Field photo showing stream conditions at site ROCK-211-R-2003-753 (Opens in a new window) Field photo showing stream conditions at site ROCK-211-R-2003-754 (Opens in a new window)

Located on NORTH BR ROCK CR in the Rock Creek watershed, 8-digit code: 02140206.
This stream was visited in the spring on 4/2/2003 and again in the summer on 7/16/2003.

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 Good - 4.0 / 5.0
Benthic IBI Fair - 3.0 / 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 4,100 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 30 %
Agricultural Land Use 44 %
Forested Land Use 26 %


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 17/20 (Optimal)
Velocity/Depth Diversity 16/20 (Optimal)
Pool Quality
Pool Extent = 55 meters 		15/20 (Suboptimal)
Riffle Quality
Riffle Extent = 26 meters 		16/20 (Optimal)
Shading 86 %
Embeddedness 18 %
Several measures of instream habitat were considered 'Optimal' at this location.


Stream Water Quality:
Water temperature 19.6 ° C
Dissolved oxygen (DO) 7.6 mg/L
pH (lab) 7.53
Conductivity 168 µmho/cm
Alkalinity
(acid neutralizing capacity) 		550 µeq/L
Dissolved organic carbon (DOC) 2.3 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
Potomac Sculpin 177
White Sucker 36
Blacknose Dace 25
Longnose Dace 12
Cutlip Minnow 11
Tessellated Darter 11
Yellow Bullhead 4
Bluegill 2
Green Sunfish 2
Largemouth Bass 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Eastern American Toad
Eastern Box Turtle
Northern Green Frog
Northern Ring-Necked Snake
Northern Spring Peeper
Northern Two-Lined Salamander
Pickerel Frog
Wood Frog

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
Stenelmis Beetle 27
Prosimulium Black Fly 21
Orthocladius Non-Biting Midges 12
Hydrobaenus Midge 6
Simulium Black Fly 5
Stegopterna Black Fly 5
Cheumatopsyche Net-Spinning Caddisfly 5
Hemerodromia Tiny Fly 5
Microtendipes Non-Biting Midges 4
Rheosmittia Non-Biting Midges 3
Optioservus Riffle Beetle 3
Diamesa Bloodworm 3
Orthocladiinae Midge 3
Ceratopogonidae Biting Midge 3
Simuliidae Black Fly 2
Neophylax Caddisfly 2
Chimarra Fingernet Caddisfly 2
Tanytarsus Non-Biting Midges 2
Amphinemura Spring Stonefly 2
Rheocricotopus Non-Biting Midges 2
Tanytarsini Non-Biting Midges 1
Hydropsyche Net-Spinning Caddisfly 1
Parametriocnemus Non-Biting Midges 1
Prostoia Spring Stonefly 1
Pisidiidae Pill Clam 1
Macronychus Riffle Beetle 1
Oulimnius Riffle Beetle 1
Prostoma Freshwater Nemertean (Ribbon Worm) 1
Hirudinea Leech 1
Nigronia Megaloptera (Dark Fishfly) 1
Enchytraeidae Aquatic Worm 1
Naididae Aquatic Worm 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.