MBSS Site Summary for: ASSA-107-X-2005


Located on Back Creek UT3 in the Assawoman Bay watershed, 8-digit code: 02130102.
This stream was visited in the spring on 4/21/2005 and again in the summer on 8/23/2005.

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 - 2.4 / 5.0

Land Use

Land use can provide important information for determining stream health.
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Catchment area 384 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 0 %
Agricultural Land Use 80 %
Forested Land Use 19 %


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

Physical Stream Habitat
Instream Habitat 6/20 (Marginal)
Epifaunal Substrate 7/20 (Marginal)
Velocity/Depth Diversity 4/20 (Poor)
Pool Quality
Pool Extent = 74 meters 		11/20 (Suboptimal)
Riffle Quality
Riffle Extent = 1 meters 		8/20 (Marginal)
Shading 95 %
Embeddedness 100 %
The embeddedness, a measure of silt on the stream bottom, was 100%. This is very high, and may adversely affect biotic communities.


Stream Water Quality:
Water temperature 20 ° C
Dissolved oxygen (DO) 5.2 mg/L
pH (lab) 6.35
Conductivity 205 µmho/cm
Alkalinity
(acid neutralizing capacity) 		290.8298 µeq/L
Dissolved organic carbon (DOC) 3.489 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 5 fish species were collected.
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Common name Count
Eastern Mudminnow 138
American Eel 59
Mummichog 35
Banded Killifish 7
Eastern Mosquitofish 1
Biologists sampling fish communities.
Electrofishing to sample fish communities.

Amphibians and Reptiles:
American Bullfrog
Northern Green Frog
Northern Watersnake

Crayfish:
No crayfish noted.

Exotic Plants:
Japanese Honeysuckle
 

Benthic Macroinvertebrates:
Sensitive taxa: Green, Tolerant: Red, Intermediate: Gold.
Genus/Family Common Name Count
Orthocladius Non-Biting Midges 41
Crangonyctidae Scud 15
Synurella Amphipod 15
Caecidotea Isopod 15
Crangonyx Amphipod 6
Hydroporus Water Beetle 5
Hydrobaenus Midge 4
Orthocladiinae Midge 1
Apsectrotanypus Non-Biting Midges 1
Physa Air-Breathing Freshwater Snail 1
Simulium Black Fly 1
Calopteryx Damselfly 1
Lumbriculidae Worm 1
Paraphaenocladius Non-Biting Midges 1
Thienemanniella Non-Biting Midges 1
Zavrelimyia Non-Biting Midges 1
Dytiscidae Predaceous Diving 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.