MBSS Site Summary for: GWYN-120-R-2023

Site Photos

Field photo showing stream conditions at site GWYN-120-R-2023_Midpoint_facing_downstream (Opens in a new window) Field photo showing stream conditions at site GWYN-120-R-2023_Midpoint_facing_upstream (Opens in a new window)

Located on HORSEHEAD BRANCH in the Gwynns Falls watershed, 8-digit code: 02130905.
This stream was visited in the spring on 3/16/2023 and again in the summer on 7/5/2023.

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 - 4.3 / 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 No data available A highly channelized urban stream with concrete banks. An example of a highly channelized urban stream.
Urban Land Use 65.6 %
Agricultural Land Use 6.6 %
Forested Land Use 26.7 %


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 16/20 (Optimal)
Velocity/Depth Diversity 14/20 (Suboptimal)
Pool Quality
Pool Extent = 50 meters 		15/20 (Suboptimal)
Riffle Quality
Riffle Extent = 25 meters 		16/20 (Optimal)
Shading 40 %
Embeddedness 35 %
Several measures of instream habitat were considered 'Optimal' at this location.


Stream Water Quality:
Water temperature 23.5 ° C
Dissolved oxygen (DO) 6.76 mg/L
pH (lab) 7.85
Alkalinity
(acid neutralizing capacity) 		1911 µeq/L
Dissolved organic carbon (DOC) 1.11 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 17 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Central Stoneroller 44
Bluegill 23
Creek Chub 22
Longnose Dace 21
White Sucker 17
Green Sunfish 14
Common Shiner 6
Smallmouth Bass 5
Pumpkinseed 4
Blacknose Dace 3
Cutlip Minnow 2
Rosyside Dace 2
American Eel 1
Largemouth Bass 1
Satinfin Shiner 1
Tessellated Darter 1
Yellow Bullhead 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
Pickerel Frog
Queen Snake

Crayfish:
Faxonius virilis

Exotic Plants:
Bamboo Sp.
Garlic Mustard
Japanese Stiltgrass
Mile-A-Minute
Multiflora Rose
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
STENELMIS Beetle 14
ORTHOCLADIUS Non-Biting Midges 12
CHEUMATOPSYCHE Net-Spinning Caddisfly 10
HYDROPSYCHE Net-Spinning Caddisfly 10
CHIMARRA Fingernet Caddisfly 9
OPTIOSERVUS Riffle Beetle 7
PSEPHENUS Water Penny 7
TVETENIA Non-Biting Midges 6
SIMULIUM Black Fly 6
NEOPHYLAX Caddisfly 5
CRICOTOPUS Non-Biting Midges 5
ANTOCHA Crane Fly 2
THIENEMANNIMYIA GROUP Non-Biting Midges 2
MACRONYCHUS Riffle Beetle 2
NEOPLASTA 2
CLINOCERA Aquatic Dance Fly 2
GLOSSOSOMA Little Black Caddisfly 2
HYDROBAENUS Midge 1
ARGIA Narrow-Winged Damselfly 1
DIPLECTRONA Net-Spinning Caddisfly 1
POLYPEDILUM Non-Biting Midges 1
RHEOTANYTARSUS Non-Biting Midges 1
SYMPOTTHASTIA Non-Biting Midges 1
THIENEMANNIELLA Non-Biting Midges 1
DIAMESA Bloodworm 1
HYDROPSYCHIDAE Common Netspinner Caddisfly 1
STENONEMA Flatheaded Mayfly 1
GIRARDIA Freshwater Flatworm 1
MICROCYLLOEPUS Riffle Beetle 1
LUMBRICULIDAE Worm 1
OULIMNIUS Riffle Beetle 1
BOYERIA Spotted Darner Dragonfly 1
ISOTOMIDAE Springtail 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.