MBSS Site Summary for: ROCK-202-B-2007

Site Photos

Field photo showing stream conditions at site ROCK-202-B-2007-1 (Opens in a new window) Field photo showing stream conditions at site ROCK-202-B-2007-2 (Opens in a new window)

Located on Rock Creek North Branch in the Rock Creek watershed, 8-digit code: 02140206.
This stream was visited in the spring on 4/10/2007 and again in the summer on 6/27/2007.

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 Poor - 2.3 / 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 6,233 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 32.1 %
Agricultural Land Use 38.5 %
Forested Land Use 29 %


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 14/20 (Suboptimal)
Velocity/Depth Diversity 13/20 (Suboptimal)
Pool Quality
Pool Extent = 66 meters 		13/20 (Suboptimal)
Riffle Quality
Riffle Extent = 23 meters 		15/20 (Suboptimal)
Shading 90 %
Embeddedness 40 %


Stream Water Quality:
Water temperature 23.1 ° C
Dissolved oxygen (DO) 6.7 mg/L
pH (lab) 7.89
Conductivity 168 µmho/cm
Alkalinity
(acid neutralizing capacity) 		642.5 µeq/L
Dissolved organic carbon (DOC) 1.1272 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
Largemouth Bass 76
Longnose Dace 75
Potomac Sculpin 41
Blacknose Dace 26
Yellow Bullhead 26
Spottail Shiner 10
White Sucker 9
Margined Madtom 6
Tessellated Darter 6
Cutlip Minnow 4
Fallfish 3
Northern Hogsucker 2
Bluntnose Minnow 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Northern Green Frog
Northern Two-Lined Salamander

Crayfish:
Orconectes virilis

Exotic Plants:
Garlic Mustard
Japanese Barberry
Japanese Honeysuckle
Japanese Stiltgrass
Mile-A-Minute
Multiflora Rose
Tree Of Heaven
Wineberry
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Diamesa Bloodworm 11
Simulium Black Fly 10
Hydrobaenus Midge 9
Cheumatopsyche Net-Spinning Caddisfly 9
Polypedilum Non-Biting Midges 7
Orthocladius Non-Biting Midges 7
Rheocricotopus Non-Biting Midges 6
Orthocladiinae Midge 6
Naididae Aquatic Worm 4
Sympotthastia Non-Biting Midges 4
Parametriocnemus Non-Biting Midges 3
Diamesinae Non-Biting Midges 3
Clinocera Aquatic Dance Fly 3
Prosimulium Black Fly 3
Stegopterna Black Fly 2
Nilotanypus 2
Pisidiidae Pill Clam 2
Paratanytarsus Non-Biting Midges 2
Thienemannimyia group Non-Biting Midges 2
Tribelos Non-Biting Midges 1
Tanytarsus Non-Biting Midges 1
Dubiraphia Riffle Beetle 1
Chelifera Aquatic Dance Fly 1
Stenelmis Beetle 1
Coenagrionidae Narrowwinged Damselfly 1
Diplectrona Net-Spinning Caddisfly 1
Cladotanytarsus Non-Biting Midge 1
Chimarra Fingernet Caddisfly 1
Stenonema Flatheaded Mayfly 1
Caecidotea Isopod 1
Nigronia Megaloptera (Dark Fishfly) 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.