MBSS Site Summary for: NCRW-214-N-2004


Located on ACCOKEEK CR in the Potomac River U tidal watershed, 8-digit code: 02140201.
This stream was visited in the spring on 4/27/2004 and again in the summer on 8/30/2004.

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 - 4.3 / 5.0
Benthic IBI Fair - 3.3 / 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 2,132 acres A stream flowing through a densely forested area. An example of a forested stream.
Urban Land Use 8 %
Agricultural Land Use 11 %
Forested Land Use 80 %


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

Physical Stream Habitat
Instream Habitat 11/20 (Suboptimal)
Epifaunal Substrate 9/20 (Marginal)
Velocity/Depth Diversity 11/20 (Suboptimal)
Pool Quality
Pool Extent = 75 meters 		11/20 (Suboptimal)
Riffle Quality
Riffle Extent = 2 meters 		6/20 (Marginal)
Shading 65 %
Embeddedness 100 %
The embeddedness, a measure of silt on the stream bottom, was 100%. This is very high, and may adversely affect biotic communities.


Stream Water Quality:
Water temperature 22.3 ° C
Dissolved oxygen (DO) 6.3 mg/L
pH (lab) 7.25
Conductivity 132 µmho/cm
Alkalinity
(acid neutralizing capacity) 		470.4 µeq/L
Dissolved organic carbon (DOC) 4.2 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 17 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Eastern Mosquitofish 510
Banded Killifish 88
Brown Bullhead 82
Creek Chubsucker 56
Creek Chub 49
Tessellated Darter 41
Eastern Mudminnow 25
Green Sunfish 20
Pumpkinseed 17
Bluegill 13
Sea Lamprey 7
American Eel 4
Blacknose Dace 4
Yellow Bullhead 3
Golden Shiner 1
Least Brook Lamprey 1
White Sucker 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Northern Green Frog

Crayfish:
Cambaridae

Exotic Plants:
No exotic plants noted.
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Crangonyctidae Scud 50
Chironomus Non-Biting Midges 26
Cricotopus Non-Biting Midges 21
Orthocladius Non-Biting Midges 10
Ceratopogonidae Biting Midge 9
Paratendipes European Non-Biting Midge 8
Calopteryx Damselfly 4
Acentrella Tiny Blue-Winged Olive Mayflies 3
Heterotrissocladius European Non-Biting Midge 2
Stenochironomus European Non-Biting Midge 2
Dicranota Hairy-Eyed Cranefly 2
Eurylophella Mayfly 2
Brillia Non-Biting Midges 1
Micropsectra Non-Biting Midges 1
Tanypodinae Non-Biting Midges 1
Thienemanniella Non-Biting Midges 1
Boyeria Spotted Darner Dragonfly 1
Amphinemura Spring Stonefly 1
Pycnopsyche Great Autumn Brown Sedge Caddisfly 1
Gomphidae Clubtail Dragonfly 1
Pseudolimnophila Crane Fly 1
Crangonyx Amphipod 1
Lepidoptera Aquatic Moth 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.