FOSC/Audubon Naturalist Society (ANS)
Biological Water Quality Monitoring/Data

The Audubon Naturalist Society has a well established, highly regarded macroinvertebrate monitoring program in the region. Friends of Sligo Creek began monitoring one site on Sligo Creek using the Audubon Naturalist Society’s water monitoring protocol in 2006. The site is located on Sligo Creek just south of where Sligo Creek Parkway meets University Boulevard in Wheaton (select the purple triangle on the map at right).

The primary goal of the monitoring is to have data for Sligo Creek represented in the Audubon Naturalist Society’s data set, which is periodically turned over to Montgomery County to help them assess the water quality of County streams. Other goals include public education, and to see for ourselves whether Sligo Creek’s water quality is getting better or worse over time. The Sligo Creek site has been named Audubon Naturalist Society Site 34.

Macroinvertebrate Monitoring Sites in Sligo Creek

Biological Monitoring Sites on Sligo Creek.
The site monitored by FOSC is located just south of University Boulevard, marked with a purple triangle

The Water Quality Committee also conducts periodic cross section surveys of the stream channel at this site to see how it changes over time.

Keep an eye out for future monitoring events on the FOSC listserv (see the link on the Home page) and join us! The next monitoring will take place on Spring 2023. You can join FOSC to get event updates and the newsletter delivered to your inbox.

NOTE: Due to the COVID pandemic, biological monitoring was suspended in Spring 2020 with intermittent testing in 2021.

FOSC/ANS Biological Monitoring Results

Date Total Aquatic Worms

(Oligochaeta) or Flatworms, Planarians


(Platyhelminthes)
Caddisflies (Trichoptera) Crayfish (Decapoda) Dragonflies and Damselflies (Odonata) Mayflies (Ephemeroptera) Scud (Amphipoda) Snail (Gastropoda) True Flies (Diptera) Clam (Bivalvia) Beetles (Coleoptera) Fishflies, etc. (Megaloptera) True Bugs (Hemiptera)
10/24/2022 47 2 planaria 17 netspinner, 22 fingernet

1 0 1 (small minnow mayfly) 2 0 0 1 (Asian) 1 riffle beetle (adult) 0 0
7/25/2022 100+ 4 aquatic worms, 12 planaria 75+ netspinner, 3 fingernet 1 3 darner dragonflies 0 2 0 6 midges, 3 crane flies 0 0 0 0
4/30/2022 100+ 22 aquatic worms 25 netspinner 1 0 65+ (small minnow mayflies) 0 0 10 midges, 4 crane flies 0 0 0 0
10/15/2021 44 1 planaria 35 netspinner, 3 fingernet 1 0 1 (small minnow mayflies) 0 0 3 crane flies 0 0 0 0
7/13/2021 67 1 planaria 60 netspinner 1 0 2 (small minnow mayflies) 0 0 3 midges 0 0 0 0
10/26/2019 102 3 planaria 38 netspinner, 55 fingernet 0 0 0 2 0 2 midges, 2 crane flies 0 0 0 0
7/23/2019 100 3 aquatic worms, 4 planaria 55 netspinner, 40 fingernet 2 0 0 0 1 (pouch snail) 5 crane flies 0 0 0 0
4/25/2019 100+ 2 aquatic worms 50+ netspinner 0 0 14 (small minnow mayflies) 0 0 21 midges, 4 crane flies 1 (Asian) 0 0 0
10/13/2018 116 0 64 netspinner 0 1 narrowed-winged damselfly 0 30 0 4 midges, 9 crane flies 7 (fingernail) 1 riffle beetle (larva) 0 0
7/31/2018 99 3 planaria 74 netspinner, 8 fingernet 0 0 0 3 0 3 midges, 6 crane flies, 1 black fly 0 0 0 1 short-legged strider
4/28/2018 40 2 aquatic worms 20 netspinner 0 4 narrowed-winged damselflies 0 3 0 10 midges, 1 black fly 0 0 0 0
10/28/2017 60 0 50 (40 netspinner, 10 fingernet) 0 0 0 0 4 (pond snails) 6 midges 0 0 0 0
4/27/2017 25 0 0 0 0 0 0 0 25 midges 0 0 0 0
10/29/2016 13 1 aquatic worm 2 0 0 0 0 0 10 (5 midges, 5 mosquitos) 0 0 0 0
7/18/2016 54+ 1 aquatic worm, 8 planaria 8 0 0 6 (small minnow mayflies) 0 0 31 (30+ midges, 1 crane fly) 0 0 0 0
4/30/2016 100+ 2 aquatic worms 0 0 0 0 2 0 96+ (95+ midges, 1 crane fly) 0 0 0 0
10/31/2015 13 0 4 0 4 broadwinged damselflies 0 0 0 5 (4 midges, 1 crane fly) 0 0 0 0
7/29/2015 11 1 aquatic worm 1 0 1 darner dragonfly 1 (small minnow mayfly) 2 1 (pond snail) 3 (2 midges, 1 crane fly) 0 0 1 (dobsonfly) 0
4/25/2015 100+ 0 20 0 0 0 0 2 (pond snails) 78+ midges 0 0 0 0
10/18/2014 10 0 7 1 0 0 1 0 1 midge 0 0 0 0
7/22/2014 100+ 0 71+ 0 5 damselflies 3 (small minnow mayflies) 4 8 (pond snails) 9 (8 midges, 1 crane fly) 0 0 0 0
4/25/2014 14 0 0 0 0 0 0 0 14 (12 midges, 2 crane flies) 0 0 0 0
10/25/2013 9 0 0 1 0 0 4 0 3 midges 0 1 riffle beetle (adult) 0 0
7/15/2013 12 0 5 1 0 0 5 0 1 crane fly 0 0 0 0
4/20/2013 100+ 4 aquatic worms 0 1 0 0 0 0 95+ midges 0 0 0 0
10/20/2012 100+ 1 (planaria) 1 0 1 darner dragonfly 0 87+ 0 10+ midges 0 0 0 0
7/31/2012 100+ 13 (planaria) 0 1 3 damselflies (2 narrow-winged, 1 broad-winged) 0 56+ 0 20+ midges 7 (fingernail) 0 0 0
4/25/2012 100+ 3 (planaria) 2 0 0 0 30+ 4 (pond snails) 61+ (60+ midges, 1 crane fly) 0 0 0 0
10/15/2011 32 4 aquatic worms, 2 planaria 9 0 0 0 16 1 (pond snail) 0 0 0 0 0
07/21/2011 100+ 3 5 1 6
(5 darner dragonflies, 1 broad-winged damselfly)
0 20 0 67+ (65+ midges, 2 mosquitos) 0 0 0 0
04/20/2011 100+ 0 17 0 1
(dragonfly)
0 12 0 70+ (67+ midges, 3 crane flies) 0 0 0 0
10/09/2010 100+ 0 1 0 3
(damselflies)
0 100+ 0 11 (10 midges, 1 crane fly) 0 0 0 0
7/06/2010 100+ 2 0 2 0 0 100+ 0 0 6 0 0 0
4/17/2010 68 5 40 0 0 3 (small minnow mayflies) 7 0 13 (10 midges, 3 crane flies 0 0 0 0
10/25/2009 100+ 1 100+ 1 2 (1 damselfly, 1 dragonfly) 0 6 0 1 (crane fly) 0 0 0 0
7/16/2009 54 0 1 0 1 (dragonfly) 12 (small minnow mayflies) 23 1 13 (12 midges, 1 crane fly) 0 0 0 0
3/28/2009 59 0 1 0 1 (damselfly) 0 24 0 33 (32 midges, 1 crane fly) 0 0 0 0
10/18/2008 100+ 2 1 1 7 (damselflies) 0 100+ 0 5 (midge) 0 0 0 0
7/5/2008 55 2 0 2 3 (2 damselflies, 1 dragonfly) 0 41 0 7 (midge) 0 0 0 0
4/5/2008 179 1 4 3 0 0 15 1 (limpet) 155 (151 midges, 3 black flies, 1 crane fly) 0 0 0 0
9/8/2007
(low flow conditions)
0 0 0 0 0 0 0 0 0 0 0 0 0
7/8/2007 26 0 13 1 0 1 (small minnow mayfly) 9 0 2 (1 midge, 1 crane fly) 0 0 0 0
5/11/2007 26 0 16 1 0 0 3 0 6 (3 midges, 2 black flies, 1 crane fly) 0 0 0 0
2/03/2007 15 1 3 0 0 0 4 0 7 (4 midges, 3 crane flies) 0 0 0 0
9/11/2006 60 0 44 1 0 0 11 0 4 (midges) 0 0 0 0
7/10/2006 100 1 5 0 0 0 84 0 10 (9 midges, 1 crane fly) 0 0 0 0
Date Total Aquatic Worms
(Oligochaeta) or Flatworms, Planarians
(Platyhelminthes) Caddisflies (Trichoptera) Crayfish (Decapoda) Dragonflies and Damselflies (Odonata) Mayflies (Ephemeroptera) Scud (Amphipoda) Snail (Gastropoda) True Flies (Diptera) Clam (Bivalvia) Beetles (Coleoptera) Fishflies, etc. (Megaloptera) True Bugs (Hemiptera) 10/24/2022 47 2 planaria 17 netspinner, 22 fingernet 1 0 1 (small minnow mayfly) 2 0 0 1 (Asian) 1 (riffle beetle adult) 0 0 7/25/2022 100+ 4 aquatic worms, 12 planaria 75+ netspinner, 3 fingernet 1 3 darner dragonflies 0 2 0 6 midges, 3 crane flies 0 0 0 0 4/30/2022 100+ 22 aquatic worms 25 netspinner 1 0 65+ (small minnow mayflies) 0 0 10 midges, 4 crane flies 0 0 0 0 10/15/2021 67 1 planaria 35 netspinner, 3 fingernet 1 0 1 (small minnow mayflies) 0 0 3 crane flies 0 0 0 0 7/13/2021 67 1 planaria 60 netspinner 1 0 2 (small minnow mayflies) 0 0 3 midges 0 0 0 0 10/26/2019 102 3 planaria 38 netspinner, 55 fingernet 0 0 0 2 0 2 midges, 2 crane flies 0 0 0 0 7/23/2019 100 3 aquatic worms, 4 planaria 55 netspinner, 40 fingernet 2 0 0 0 1 (pouch snail) 5 crane flies 0 0 0 0 4/25/2019 100+ 2 aquatic worms 50+ netspinner 0 0 14 (small minnow mayflies) 0 0 21 midges, 4 crane flies 1 (Asian) 0 0 0 10/13/2018 116 0 64 netspinner 0 1 narrowed-winged damselfly 0 30 0 4 midges, 9 crane flies 7 (fingernail) 1 riffle beetle (larva) 0 0 7/31/2018 99 3 planaria 74 netspinner, 8 fingernet 0 0 0 3 0 3 midges, 6 crane flies, 1 black fly 0 0 0 1 short-legged strider 4/28/2018 40 2 aquatic worms 20 netspinner 0 4 narrowed-winged damselflies 0 3 0 10 midges, 1 black fly 0 0 0 0 10/28/2017 60 0 50 (40 netspinner, 10 fingernet) 0 0 0 0 4 (pond snails) 6 midges 0 0 0 0 4/27/2017 25 0 0 0 0 0 0 0 25 midges 0 0 0 0 10/29/2016 13 1 aquatic worm 2 0 0 0 0 0 10 (5 midges, 5 mosquitos) 0 0 0 0 7/18/2016 54+ 1 aquatic worm, 8 planaria 8 0 0 6 (small minnow mayflies) 0 0 31 (30+ midges, 1 crane fly) 0 0 0 0 4/30/2016 100+ 2 aquatic worms 0 0 0 0 2 0 96+ (95+ midges, 1 crane fly) 0 0 0 0 10/31/2015 13 0 4 0 4 broadwinged damselflies 0 0 0 5 (4 midges, 1 crane fly) 0 0 0 0 7/29/2015 11 1 aquatic worm 1 0 1 darner dragonfly 1 (small minnow mayfly) 2 1 (pond snail) 3 (2 midges, 1 crane fly) 0 0 1 (dobsonfly) 0 4/25/2015 100+ 0 20 0 0 0 0 2 (pond snails) 78+ midges 0 0 0 0 10/18/2014 10 0 7 1 0 0 1 0 1 midge 0 0 0 0 7/22/2014 100+ 0 71+ 0 5 damselflies 3 (small minnow mayflies) 4 8 (pond snails) 9 (8 midges, 1 crane fly) 0 0 0 0 4/25/2014 14 0 0 0 0 0 0 0 14 (12 midges, 2 crane flies) 0 0 0 0 10/25/2013 9 0 0 1 0 0 4 0 3 midges 0 1 riffle beetle (adult) 0 0 7/15/2013 12 0 5 1 0 0 5 0 1 crane fly 0 0 0 0 4/20/2013 100+ 4 aquatic worms 0 1 0 0 0 0 95+ midges 0 0 0 0 10/20/2012 100+ 1 (planaria) 1 0 1 darner dragonfly 0 87+ 0 10+ midges 0 0 0 0 7/31/2012 100+ 13 (planaria) 0 1 3 damselflies (2 narrow-winged, 1 broad-winged) 0 56+ 0 20+ midges 7 (fingernail) 0 0 0 4/25/2012 100+ 3 (planaria) 2 0 0 0 30+ 4 (pond snails) 61+ (60+ midges, 1 crane fly) 0 0 0 0 10/15/2011 32 4 aquatic worms, 2 planaria 9 0 0 0 16 1 (pond snail) 0 0 0 0 0 07/21/2011 100+ 3 5 1 6
(5 darner dragonflies, 1 broad-winged damselfly) 0 20 0 67+ (65+ midges, 2 mosquitos) 0 0 0 0 04/20/2011 100+ 0 17 0 1
(dragonfly) 0 12 0 70+ (67+ midges, 3 crane flies) 0 0 0 0 10/09/2010 100+ 0 1 0 3
(damselflies) 0 100+ 0 11 (10 midges, 1 crane fly) 0 0 0 0 7/06/2010 100+ 2 0 2 0 0 100+ 0 0 6 0 0 0 4/17/2010 68 5 40 0 0 3 (small minnow mayflies) 7 0 13 (10 midges, 3 crane flies 0 0 0 0 10/25/2009 100+ 1 100+ 1 2 (1 damselfly, 1 dragonfly) 0 6 0 1 (crane fly) 0 0 0 0 7/16/2009 54 0 1 0 1 (dragonfly) 12 (small minnow mayflies) 23 1 13 (12 midges, 1 crane fly) 0 0 0 0 3/28/2009 59 0 1 0 1 (damselfly) 0 24 0 33 (32 midges, 1 crane fly) 0 0 0 0 10/18/2008 100+ 2 1 1 7 (damselflies) 0 100+ 0 5 (midge) 0 0 0 0 7/5/2008 55 2 0 2 3 (2 damselflies, 1 dragonfly) 0 41 0 7 (midge) 0 0 0 0 4/5/2008 179 1 4 3 0 0 15 1 (limpet) 155 (151 midges, 3 black flies, 1 crane fly) 0 0 0 0 9/8/2007
(low flow conditions) 0 0 0 0 0 0 0 0 0 0 0 0 0 7/8/2007 26 0 13 1 0 1 (small minnow mayfly) 9 0 2 (1 midge, 1 crane fly) 0 0 0 0 5/11/2007 26 0 16 1 0 0 3 0 6 (3 midges, 2 black flies, 1 crane fly) 0 0 0 0 2/03/2007 15 1 3 0 0 0 4 0 7 (4 midges, 3 crane flies) 0 0 0 0 9/11/2006 60 0 44 1 0 0 11 0 4 (midges) 0 0 0 0 7/10/2006 100 1 5 0 0 0 84 0 10 (9 midges, 1 crane fly) 0 0 0 0