MBSS Site Summary for: PAXU-109-R-2004

Site Photos

Field photo showing stream conditions at site PAXU-109-R-2004-72 (Opens in a new window) Field photo showing stream conditions at site PAXU-109-R-2004-73 (Opens in a new window)

Located on STOCKETTS RUN in the Patuxent River upper watershed, 8-digit code: 02131104.
This stream was visited in the spring on 3/10/2004 and again in the summer on 6/3/2004.

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 Poor - 1.7 / 5.0
Benthic IBI Fair - 3.0 / 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 1,320 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 3 %
Agricultural Land Use 56 %
Forested Land Use 40 %


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

Physical Stream Habitat
Instream Habitat 8/20 (Marginal)
Epifaunal Substrate 8/20 (Marginal)
Velocity/Depth Diversity 11/20 (Suboptimal)
Pool Quality
Pool Extent = 63 meters 		13/20 (Suboptimal)
Riffle Quality
Riffle Extent = 12 meters 		7/20 (Marginal)
Shading 85 %
Embeddedness 70 %
The embeddedness, a measure of silt on the stream bottom, was 70%. This is relatively high, and may exclude some biota.


Stream Water Quality:
Water temperature 16.9 ° C
Dissolved oxygen (DO) 9.2 mg/L
pH (lab) 6.77
Conductivity 189 µmho/cm
Alkalinity
(acid neutralizing capacity) 		275.9 µeq/L
Dissolved organic carbon (DOC) 1.6 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 6 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Blacknose Dace 65
Tessellated Darter 11
Eastern Mudminnow 8
White Sucker 2
American Eel 1
Green Sunfish 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

Crayfish:
No crayfish noted.

Exotic Plants:
Japanese Honeysuckle
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Gammarus Amphipod 36
Orthocladius Non-Biting Midges 28
Hydrobaenus Midge 20
Parametriocnemus Non-Biting Midges 12
Limnephilidae Northern Casemaker Caddisfly 5
Prostoia Spring Stonefly 3
Rheosmittia Non-Biting Midges 3
Thienemanniella Non-Biting Midges 3
Prosimulium Black Fly 3
Stegopterna Black Fly 3
Tubificidae Aquatic Worm 2
Brillia Non-Biting Midges 2
Micropsectra Non-Biting Midges 2
Allocapnia Small Winter Stonefly 2
Capniidae Small Winter Stonefly 2
Tvetenia Non-Biting Midges 2
Ironoquia Northern Caddisfly 2
Acerpenna Tiny Blue-Winged Olive Mayflies 1
Hydrobius Water Scavenger Beetle 1
Eukiefferiella Non-Biting Midges 1
Thienemannimyia group Non-Biting Midges 1
Tanypodinae Non-Biting Midges 1
Orthocladiinae Midge 1
Nemouridae Nemourid Stonefly 1
Tipula Crane Fly 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.