MBSS Site Summary for: RKGR-403-R-2002

Site Photos

Field photo showing stream conditions at site RKGR-403-R-2002-1 (Opens in a new window) Field photo showing stream conditions at site RKGR-403-R-2002-2 (Opens in a new window)

Located on PATUXENT R in the Rocky Gorge Dam watershed, 8-digit code: 02131107.
This stream was visited in the spring on 3/19/2002 and again in the summer on 8/5/2002.

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 Fair - 3.0 / 5.0
Benthic IBI Poor - 2.0 / 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 69,342 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 64 %
Forested Land Use 30 %


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 13/20 (Suboptimal)
Velocity/Depth Diversity 11/20 (Suboptimal)
Pool Quality
Pool Extent = 75 meters 		14/20 (Suboptimal)
Riffle Quality
Riffle Extent = 4 meters 		16/20 (Optimal)
Shading 80 %
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 21.6 ° C
Dissolved oxygen (DO) 5.5 mg/L
pH (lab) 7.87
Conductivity 160 µmho/cm
Alkalinity
(acid neutralizing capacity) 		491.6 µeq/L
Dissolved organic carbon (DOC) 2.2 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 21 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Tessellated Darter 229
Bluegill 184
Largemouth Bass 72
White Sucker 60
Fallfish 25
Spottail Shiner 22
Yellow Perch 21
Margined Madtom 20
Satinfin Shiner 19
Green Sunfish 18
Northern Hogsucker 18
River Chub 15
Redbreast Sunfish 7
Gizzard Shad 5
Swallowtail Shiner 5
Spotfin Shiner 3
Creek Chub 2
Yellow Bullhead 2
Brown Bullhead 1
Central Stoneroller 1
Longnose Dace 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Northern Two-Lined Salamander

Crayfish:
No crayfish noted.

Exotic Plants:
Japanese Honeysuckle
Japanese Stiltgrass
Multiflora Rose
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Tanytarsus Non-Biting Midges 12
Cricotopus Non-Biting Midges 11
Tribelos Non-Biting Midges 10
Orthocladius Non-Biting Midges 8
Rheocricotopus Non-Biting Midges 8
Crangonyx Amphipod 8
Conchapelopia Non-Biting Midges 7
Tubificidae Aquatic Worm 6
Nanocladius Non-Biting Midges 6
Rheosmittia Non-Biting Midges 6
Paratanytarsus Non-Biting Midges 3
Hyalella Amphipod 3
Sphaerium Fingernail Clam 3
Stenonema Flatheaded Mayfly 2
Cheumatopsyche Net-Spinning Caddisfly 2
Glyptotendipes 2
Microtendipes Non-Biting Midges 2
Ceratopogonidae Biting Midge 2
Parakiefferiella European Non-Biting Midge 2
Polycentropus Tube Maker Caddisfly 2
Thienemanniella Non-Biting Midges 2
Hemerodromia Tiny Fly 1
Parametriocnemus Non-Biting Midges 1
Hydroporus Water Beetle 1
Corixidae Water Boatman 1
Chrysops Deerfly 1
Dicrotendipes Non-Biting Midges 1
Physa Air-Breathing Freshwater Snail 1
Ablabesmyia Non-Biting Midge 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.