MBSS Site Summary for: PAXU-258-T-2007

Site Photos

Field photo showing stream conditions at site PAXU-258-T-2007-1 (Opens in a new window) Field photo showing stream conditions at site PAXU-258-T-2007-2 (Opens in a new window)

Located on Mount Nebo Branch in the Patuxent River upper watershed, 8-digit code: 02131104.
This stream was visited in the spring on 4/19/2007 and again in the summer on 7/20/2007.

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 Good - 4.0 / 5.0
Benthic IBI Poor - 2.7 / 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 2,326 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 10.5 %
Agricultural Land Use 48.8 %
Forested Land Use 40.2 %


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

Physical Stream Habitat
Instream Habitat 10/20 (Marginal)
Epifaunal Substrate 10/20 (Marginal)
Velocity/Depth Diversity 11/20 (Suboptimal)
Pool Quality
Pool Extent = 62 meters 		12/20 (Suboptimal)
Riffle Quality
Riffle Extent = 13 meters 		8/20 (Marginal)
Shading 95 %
Embeddedness 35 %


Stream Water Quality:
Water temperature 19.4 ° C
Dissolved oxygen (DO) 8.5 mg/L
pH (lab) 7.29
Conductivity 349 µmho/cm
Alkalinity
(acid neutralizing capacity) 		653.9 µeq/L
Dissolved organic carbon (DOC) 2.2922 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
Blacknose Dace 50
American Eel 33
Rosyside Dace 30
Tessellated Darter 18
Fallfish 16
Least Brook Lamprey 8
White Sucker 6
Green Sunfish 5
Eastern Mudminnow 4
Bluegill 2
Redbreast Sunfish 2
Largemouth Bass 1
Redfin Pickerel 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Eastern Cricket Frog
Northern Green Frog
Northern Spring Peeper
Northern Two-Lined Salamander
Northern Watersnake
Pickerel Frog
Southern Leopard Frog

Crayfish:
Orconectes limosus
Orconectes virilis

Exotic Plants:
Japanese Honeysuckle
Japanese Stiltgrass
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Orthocladius Non-Biting Midges 33
Hydrobaenus Midge 25
Simulium Black Fly 10
Polypedilum Non-Biting Midges 7
Eukiefferiella Non-Biting Midges 4
Amphinemura Spring Stonefly 3
Orthocladiinae Midge 3
Tipula Crane Fly 2
Stenelmis Beetle 2
Prosimulium Black Fly 2
Pseudorthocladius Non-Biting Midges 2
Tanytarsus Non-Biting Midges 1
Trissopelopia Non-Biting Midges 1
Ironoquia Northern Caddisfly 1
Ancyronyx Spider Riffle Beetle 1
Hydroporus Water Beetle 1
Limnodrilus Worm 1
Lumbriculidae Worm 1
Diamesa Bloodworm 1
Chrysops Deerfly 1
Brillia Non-Biting Midges 1
Gammarus Amphipod 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.