MBSS Site Summary for: GWYN-105-R-2004


Located on HORSEHEAD BR in the Gwynns Falls watershed, 8-digit code: 02130905.
This stream was visited in the spring on 3/17/2004 and again in the summer on 6/16/2004.

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 - 2.7 / 5.0
Benthic IBI Poor - 2.3 / 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 1,232 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 32 %
Agricultural Land Use 37 %
Forested Land Use 31 %


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

Physical Stream Habitat
Instream Habitat 15/20 (Suboptimal)
Epifaunal Substrate 17/20 (Optimal)
Velocity/Depth Diversity 13/20 (Suboptimal)
Pool Quality
Pool Extent = 37 meters 		12/20 (Suboptimal)
Riffle Quality
Riffle Extent = 40 meters 		12/20 (Suboptimal)
Shading 92 %
Embeddedness 20 %


Stream Water Quality:
Water temperature 19.3 ° C
Dissolved oxygen (DO) 8.6 mg/L
pH (lab) 8.33
Conductivity 295 µmho/cm
Alkalinity
(acid neutralizing capacity) 		1091 µeq/L
Dissolved organic carbon (DOC) 2.1 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 9 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Longnose Dace 22
Green Sunfish 21
Creek Chub 12
Blacknose Dace 7
Rosyside Dace 7
Tessellated Darter 7
White Sucker 5
Central Stoneroller 3
Fathead Minnow 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Eastern American Toad
Eastern Red-Backed Salamander
Gray Treefrog
Marbled Salamander
Northern Green Frog
Northern Two-Lined Salamander
Wood Frog

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
Orthocladius Non-Biting Midges 50
Sympotthastia Non-Biting Midges 16
Cheumatopsyche Net-Spinning Caddisfly 11
Hydropsyche Net-Spinning Caddisfly 8
Antocha Crane Fly 5
Brillia Non-Biting Midges 4
Thienemannimyia group Non-Biting Midges 4
Tvetenia Non-Biting Midges 4
Isonychia Slate Drake Mayfly 4
Optioservus Riffle Beetle 3
Tipula Crane Fly 3
Glossosoma Little Black Caddisfly 3
Orthocladiinae Midge 2
Diamesinae Non-Biting Midges 2
Diplectrona Net-Spinning Caddisfly 2
Parametriocnemus Non-Biting Midges 2
Eukiefferiella Non-Biting Midges 1
Micropsectra Non-Biting Midges 1
Stenonema Flatheaded Mayfly 1
Simuliidae Black Fly 1
Stegopterna Black Fly 1
Diamesa Bloodworm 1
Gomphidae Clubtail Dragonfly 1
Oulimnius Riffle Beetle 1
Leptophlebiidae Pronggilled Mayfly 1
Thienemanniella 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.