MBSS Site Summary for: NANJ-331-S-2000


Located on MILL RUN in the Nanjemoy Creek watershed, 8-digit code: 02140110.
This stream was visited in the spring on 5/1/2000 and again in the summer on 8/24/2000.

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 - 3.9 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 6,282 acres A stream flowing through a densely forested area. An example of a forested stream.
Urban Land Use 4 %
Agricultural Land Use 13 %
Forested Land Use 81.2 %


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 11/20 (Suboptimal)
Velocity/Depth Diversity 15/20 (Suboptimal)
Pool Quality
Pool Extent = 65 meters 		16/20 (Optimal)
Riffle Quality
Riffle Extent = 15 meters 		7/20 (Marginal)
Shading 94 %
Embeddedness 80 %
The embeddedness, a measure of silt on the stream bottom, was 80%. This is relatively high, and may exclude some biota.


Stream Water Quality:
Water temperature 20.4 ° C
Dissolved oxygen (DO) 7.2 mg/L
pH (lab) 6.47
Conductivity 50 µmho/cm
Alkalinity
(acid neutralizing capacity) 		83.3 µeq/L
Dissolved organic carbon (DOC) 3.1 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 15 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Eastern Mosquitofish 42
Tessellated Darter 24
White Sucker 17
Largemouth Bass 7
American Eel 4
Pumpkinseed 4
Bluegill 3
Creek Chub 3
Creek Chubsucker 3
Brown Bullhead 2
Eastern Mudminnow 2
Margined Madtom 2
Chain Pickerel 1
Redbreast Sunfish 1
Yellow Bullhead 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog

Crayfish:
No crayfish noted.

Exotic Plants:
No exotic plants noted.
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Ephemerella Sulphur Mayfly 72
Simulium Black Fly 13
Acentrella Tiny Blue-Winged Olive Mayflies 11
Oulimnius Riffle Beetle 3
Crangonyctidae Scud 2
Amphinemura Spring Stonefly 2
Eurylophella Mayfly 2
Cladotanytarsus Non-Biting Midge 1
Stenonema Flatheaded Mayfly 1
Ranatra 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.