MBSS Site Summary for: PAXM-111-X-2006


Located on Swan Point Creek in the Patuxent River middle watershed, 8-digit code: 02131102.
This stream was visited in the spring on 3/29/2006 and again in the summer on 7/19/2006.

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 - 1.3 / 5.0
Benthic IBI Fair - 3.6 / 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 325 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 4 %
Agricultural Land Use 53 %
Forested Land Use 42 %


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

Physical Stream Habitat
Instream Habitat 5/20 (Poor)
Epifaunal Substrate 7/20 (Marginal)
Velocity/Depth Diversity 6/20 (Marginal)
Pool Quality
Pool Extent = 50 meters 		7/20 (Marginal)
Riffle Quality
Riffle Extent = 33 meters 		6/20 (Marginal)
Shading 95 %
Embeddedness 85 %
The embeddedness, a measure of silt on the stream bottom, was 85%. This is relatively high, and may exclude some biota.


Stream Water Quality:
Water temperature 21.6 ° C
Dissolved oxygen (DO) 8.6 mg/L
pH (lab) 6.88
Conductivity 148 µmho/cm
Alkalinity
(acid neutralizing capacity) 		255.6 µeq/L
Dissolved organic carbon (DOC) 1.8781 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 3 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Blacknose Dace 28
Eastern Mudminnow 16
Green Sunfish 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Northern Green Frog
Pickerel Frog

Crayfish:
No crayfish noted.

Exotic Plants:
Japanese Honeysuckle
Japanese Stiltgrass
Mile-A-Minute
Multiflora Rose
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Orthocladius Non-Biting Midges 33
Gammarus Amphipod 17
Amphinemura Spring Stonefly 16
Diplocladius Non-Biting Midges 14
Parametriocnemus Non-Biting Midges 8
Micropsectra Non-Biting Midges 5
Thienemannimyia group Non-Biting Midges 5
Pseudolimnophila Crane Fly 4
Musculium Fingernail Clam 3
Capniidae Small Winter Stonefly 3
Caecidotea Isopod 2
Nemouridae Nemourid Stonefly 2
Menetus Air Breathing Freshwater Snail 1
Hydrobaenus Midge 1
Tanytarsus Non-Biting Midges 1
Siphlonurus Gray Drake Mayfly 1
Heterotrissocladius European Non-Biting Midge 1
Tubificidae Aquatic Worm 1
Prosimulium Black Fly 1
Stegopterna Black Fly 1
Zavrelimyia Non-Biting Midges 1
Hydroporus Water Beetle 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.