MBSS Site Summary for: NANJ-331-S-2007

Site Photos


Located on Mill Run in the Nanjemoy Creek watershed, 8-digit code: 02140110.
This stream was visited in the spring on 3/28/2007 and again in the summer on 6/13/2007.

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 Good - 4.7 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 6,272 acres A stream flowing through a densely forested area. An example of a forested stream.
Urban Land Use 2.7 %
Agricultural Land Use 20.4 %
Forested Land Use 75.3 %


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

Physical Stream Habitat

Instream Habitat 14/20 (Suboptimal)
Epifaunal Substrate 8/20 (Marginal)
Velocity/Depth Diversity 11/20 (Suboptimal)
Pool Quality
Pool Extent = 57 meters
14/20 (Suboptimal)
Riffle Quality
Riffle Extent = 36 meters
8/20 (Marginal)
Shading 95 %
Embeddedness 60 %
The embeddedness, a measure of silt on the stream bottom, was 60%. This is relatively high, and may exclude some biota.


Stream Water Quality:

Water temperature 19.1 ° C
Dissolved oxygen (DO) 7.2 mg/L
pH (lab) 6.63
Conductivity 62 µmho/cm
Alkalinity
(acid neutralizing capacity)
86.3 µeq/L
Dissolved organic carbon (DOC) 2.7063 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 9 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Eastern Mudminnow 15
Sea Lamprey 11
Pumpkinseed 5
Tessellated Darter 5
American Eel 4
Blacknose Dace 2
Bluegill 1
Brown Bullhead 1
Eastern Silvery Minnow 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:

American Bullfrog
Eastern American Toad
Northern Green Frog
Northern Two-Lined Salamander
Pickerel Frog

Crayfish:

Orconectes limosus
Procambarus clarkii

Exotic Plants:

Japanese Honeysuckle
Japanese Stiltgrass
Multiflora Rose
 

Benthic Macroinvertebrates:

Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Eurylophella Mayfly 12
Acerpenna Tiny Blue-Winged Olive Mayflies 9
Ancyronyx Spider Riffle Beetle 7
Hydrobaenus Midge 7
Rheocricotopus Non-Biting Midges 6
Macronychus Riffle Beetle 5
Orthocladius Non-Biting Midges 5
Trissopelopia Non-Biting Midges 4
Probezzia Biting Midges 4
Ephemerella Sulphur Mayfly 3
Synurella Amphipod 2
Siphloplecton Cleftfooted Minnow Mayfly 2
Orthocladiinae Midge 2
Pycnopsyche Great Autumn Brown Sedge Caddisfly 2
Thienemannimyia group Non-Biting Midges 2
Phaenopsectra Non-Biting Midges 2
Polypedilum Non-Biting Midges 2
Parametriocnemus Non-Biting Midges 2
Cheumatopsyche Net-Spinning Caddisfly 2
Diplectrona Net-Spinning Caddisfly 1
Ablabesmyia Non-Biting Midge 1
Diplocladius Non-Biting Midges 1
Paraphaenocladius Non-Biting Midges 1
Paratanytarsus Non-Biting Midges 1
Dubiraphia Riffle Beetle 1
Leuctra  Rolled-Winged Stonefly 1
Clioperla Green-Winged Stonefly 1
Caecidotea Isopod 1
Triaenodes Long-Horned Caddisfly 1
Xylotopus Midge 1
Gomphidae Clubtail Dragonfly 1
Ameletus Combmouthed Minnow Mayfly 1
Heterotrissocladius European Non-Biting Midge 1
Musculium Fingernail Clam 1
Stenonema Flatheaded Mayfly 1
Lepidoptera Aquatic Moth 1
Stenelmis Beetle 1
Prosimulium Black Fly 1
Neophylax Caddisfly 1
Prostoia Spring Stonefly 1
Isoperla Stripetail Stonefly 1
Lumbriculidae 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.