MBSS Site Summary for: MPAX-409-R-2002

Site Photos

Field photo showing stream conditions at site MPAX-409-R-2002-1 (Opens in a new window) Field photo showing stream conditions at site MPAX-409-R-2002-2 (Opens in a new window) Field photo showing stream conditions at site MPAX-409-R-2002-3 (Opens in a new window)

Located on MIDDLE PATUXENT R in the Middle Patuxent River watershed, 8-digit code: 02131106.
This stream was visited in the spring on 4/3/2002 and again in the summer on 7/31/2002.

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 34,579 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 9 %
Agricultural Land Use 66 %
Forested Land Use 23 %


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

Physical Stream Habitat
Instream Habitat 16/20 (Optimal)
Epifaunal Substrate 12/20 (Suboptimal)
Velocity/Depth Diversity 12/20 (Suboptimal)
Pool Quality
Pool Extent = 75 meters 		14/20 (Suboptimal)
Riffle Quality
Riffle Extent = 21 meters 		12/20 (Suboptimal)
Shading 85 %
Embeddedness 80 %
The embeddedness, a measure of silt on the stream bottom, was 80%. This is relatively high, and may exclude some biota.


Stream Water Quality:
Water temperature 23.9 ° C
Dissolved oxygen (DO) 4.6 mg/L
Dissolved oxygen levels measured in the stream were very low (4.6 mg/L). Many fishes and other aquatic animals cannot tolerate low levels of oxygen in the water.
pH (lab) 7.68
Conductivity 260 µmho/cm
Alkalinity
(acid neutralizing capacity) 		1053 µeq/L
Dissolved organic carbon (DOC) 1.9 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 20 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Tessellated Darter 1903
Fallfish 563
Common Shiner 269
White Sucker 203
Swallowtail Shiner 89
Smallmouth Bass 57
River Chub 47
Rosyside Dace 42
Redbreast Sunfish 26
Longnose Dace 25
Cutlip Minnow 23
Creek Chub 15
Blacknose Dace 14
American Eel 12
Margined Madtom 12
Satinfin Shiner 12
Green Sunfish 11
Rosyface Shiner 9
Northern Hogsucker 2
Pumpkinseed 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Eastern American Toad
Fowler's Toad
Northern Two-Lined Salamander
Northern Watersnake
Pickerel Frog

Crayfish:
No crayfish noted.

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

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Cricotopus Non-Biting Midges 20
Simuliidae Black Fly 18
Orthocladius Non-Biting Midges 16
Tvetenia Non-Biting Midges 12
Paratendipes European Non-Biting Midge 8
Conchapelopia Non-Biting Midges 7
Hemerodromia Tiny Fly 6
Ephemerella Sulphur Mayfly 3
Cheumatopsyche Net-Spinning Caddisfly 3
Ablabesmyia Non-Biting Midge 3
Orthocladiinae Midge 3
Macronychus Riffle Beetle 2
Isonychia Slate Drake Mayfly 1
Baetidae Small Minnow Mayfly 1
Amphinemura Spring Stonefly 1
Chelifera Aquatic Dance Fly 1
Polycentropus Tube Maker Caddisfly 1
Argia Narrow-Winged Damselfly 1
Lype Net Tube Caddisfly 1
Perlidae Common Stonefly 1
Antocha Crane Fly 1
Empididae Dance Fly 1
Brillia Non-Biting Midges 1
Corynoneura Non-Biting Midges 1
Sympotthastia Non-Biting Midges 1
Cryptochironomus Non-Biting Midges 1
Microtendipes Non-Biting Midges 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.