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Stream Explorers

Stream Explorers is a new community science project featuring aquatic insects and what they can tell us about wildlife habitat and water quality.
Imagine This: Two volunteers are standing in a shallow stream in the Sebago Lake Watershed. They’re facing downstream, wearing sneakers or waders, and kicking the bottom of the stream to dislodge debris into long-poled, fine-mesh nets called kick-nets. Next, the volunteers gather, sort, and analyze the insects they find. Working at a portable table on the stream bank, they work with trays, spoons, droppers, and jars to separate each specimen and compare their findings against a graphic checklist of aquatic insects. These volunteers are not field biologists; rather, they are community scientists trained to identify target insect species, and classify them into categories of the “least wanted” and “most wanted” insects based on their tolerance to water pollution.

This could be you!

Interested in seeing where Stream Explorers are sampling and what critters have been found? Take a look at the map viewer and start exploring the streams in Maine!

Next workshops:
May 3, 2024 – Educators Workshop, Augusta –Register Here

May 16, 2024 – Stream Explorer training, Gardiner – Register Here

Additionally, 2022 training webinars were recorded and are available to view anytime. 

Part 1 (Introduction, Methods, and Survey 123)
Part 2 (Macroinvertebrate identification)

Email to get involved!

The Maine Stream Explorers Partnership
Maine Audubon is partnering with the Lakes Environmental Association (LEA), the Maine Department of Environmental Protection (DEP), and the Portland Water District to recruit, train, and support volunteers interested in searching streams in the Sebago Lake Watershed for large aquatic insects that are indicators of water quality.

Who are aquatic insects and why are they important?

Large aquatic insects (or macroinvertebrates) are excellent indicators of water quality and a changing environment. Some macroinvertebrates require cold, clean water and high-quality habitat. Other macroinvertebrates are tolerant of warm, polluted water or poor habitat quality. As such, the presence or absence of different species can inform us about both water quality and the ecological health of a stream.

In addition to providing insight into the overall health of streams and rivers, macroinvertebrate samples provide a wealth of information about the type of environmental stressors harming streams and rivers. Macroinvertebrates are an important food source for many other aquatic and semi-aquatic species; and they are often the basis for much of the stream food web. If one or more species or species groups is missing, or there are very few insects in the stream, the rest of the aquatic food web will be affected.

Stream Explorer volunteers can help!

There are over 5,000 rivers and streams in Maine, but DEP is only able to sample 50 to 60 per year, focusing on one of five regions of Maine in any given year. DEP simply does not have the resources to adequately monitor water quality in all of Maine’s streams. There is a real need for screening-level surveys to help track water quality over time and obtain information about streams that have never been surveyed. That’s where volunteers can help!

Maine Audubon and partners will train and support volunteer Stream Explorers to monitor stream water quality and changes over time that may be related to land use practices and a changing climate. Although the volunteer data will not be used to determine if a stream meets water quality standards, the data will be tremendously valuable for prioritizing where to focus DEP’s more in-depth surveys. Because aquatic macroinvertebrates are just that–macro!–they are relatively easy to find and identify (at least to Order and sometimes Family) without the need for expensive microscopes, making them ideal targets for community scientists to find, identify, and record. Most importantly, macroinvertebrates can be used as effective indicators of the health of our aquatic systems–typically a more diverse group of species means a healthier stream.

What do I need to know to volunteer?

Volunteer Stream Explorers do not need prior experience with stream surveying or aquatic insect identification.  We will teach you everything you need to know and provide support to you throughout the survey season as needed.

Volunteers must watch two training videos (recorded webinars, available via YouTube) to learn how to identify the different types of aquatic insects you are likely to find, along with instructions on how to conduct the survey.

Training Part 1

Training Part 2

We will provide volunteers with a guidebook that includes an overview of the program, details on how to conduct a stream survey, tips for identifying a select list of stream insects, survey data forms, and contact information for participating partners.  We will also have recordings of the webinar and a virtual tour of a stream survey available for viewing and reference.  All materials are available digitally and hard copies may be requested if absolutely needed.

Survey equipment kits are available for check-out, loan and curb-side pick-up at different partner organizations and locations. See table below for locations and contact person.

Gilsland Farm Audubon Center
20 Gilsland Farm Rd., Falmouth, ME 04105
Contact person: Hannah Young,
Portland Water District, Lake Office
1 White Rock Rd., Standish, ME
Contact person: Carina Brown,
Lakes Environmental Association
230 Main St., Bridgton, ME
Contact person: Shannon Nelligan,
Cumberland Country Soil and Water Conservation District
35 Maine St #3, Windham, ME
Contact person: Ali Clift, 207-892-4700
Lake Auburn Watershed Protection Commission
268 Court St., Auburn, ME
Contact person: Erica Kidd,, 207-333-6665
Midcoast Conservancy
25 Friendship St, Waldoboro, ME
Contact person: Morganne Price,

Materials and Resources
We have created detailed training materials and reference guides, illustrated identification keys, and illustrated data forms for volunteers to use in the field. Stream Explorers can follow the Basic or Advanced version of the materials. The Basic version groups the macroinvertebrates in types (mayflies, stoneflies, dragonflies, etc.) while the Advanced version identifies species within each group. Feel free to use whichever version you’re most comfortable with.

Introduction and Sampling Instructions (for both Basic and Advanced)

Basic Advanced
Guide Guide
Identification Key Identification Key
Data Form Data Form

You can also enter your data online via a Survey 123 online form. You can do this while you are in the field surveying or you can use paper forms in the field and input the data online once you get home! Use your smartphone to read the QR code below.


Want to test your ID skills? Click below for quizzes! (Little tip- they get harder as you go!)

Quiz 1

Quiz 2

Quiz 3

Quiz 4

Quiz 5

How much time is involved?

We encourage interested volunteers to commit to surveying at least one, but preferably two to three streams between August and October.  Each survey will take around 1.5 to 2 hours to complete, plus travel time. Please mail or scan and email your completed surveys to Maine Audubon at soon after each survey, but no later than November 30.  We also encourage volunteers to survey in pairs for safety reasons, or to make a family adventure of it!

With respect to COVID-19, please stay safe by following these precautions from the Maine Center for Disease Control.  Your biggest risks are probably stopping for gas or a snack rather than wading in the stream to search for insects.

Where can I survey?

We focused initially on 30 to 40 streams in the Sebago Lake watershed and south of the watershed that had not been surveyed recently by DEP. We will continue to survey these streams, as well as add additional locations across southern Maine. This ties in nicely with goals of the Portland Water District to keep the water supply for nearly 200,000 Mainers clean, and will help DEP cover an area of the state for which they have little data. Starting with the Sebago Lake watershed will also provide an excellent opportunity to learn about the connection between the health of these streams and the health of Casco Bay.

If you have a particular stream you’re interested in but it’s not in this region, that’s okay! Stream Explorers are supposed to explore. If there is a site in your town/neighborhood/backyard that you’d like to sample, we think that’s a great idea.

You can also choose a site from lists compiled by DEP.

Who else currently surveys Maine streams for aquatic insects?

The Maine Department of Environmental Protection (DEP) surveys aquatic macroinvertebrates in streams and rivers across Maine. DEP uses aquatic macroinvertebrates as the primary indicator of stream health and as a “canary in the coal mine” for troubled waters, because they are sensitive to temperature, sediment, pollutants, and many other environmental stressors. DEP staff use the data in statistical models based on the diversity, abundance, and pollution tolerance of macroinvertebrates to determine if streams and rivers attain water quality standards associated with the classification of the streams and rivers (Classes AA, A, B, C, see map to right).

This monitoring is required by the Clean Water Act and the results are included in biennial reports to Congress summarizing the condition of Maine waters.

What else will the data tell us?

Worsening conditions in Casco Bay are exacerbated by increased development, conversion of forests, erosion and sedimentation, and use of fertilizers and pesticides throughout the Casco Bay Watershed. Our best hope to avoid further degradation is to engage more community members and leaders in understanding first-hand how human behaviors affect the streams that feed Casco Bay including those in the Sebago Lake Watershed as well as Casco Bay itself.

Furthermore, although the primary objective of this program is to collect survey data on macroinvertebrates to better understand water quality in Maine, there is also a secondary benefit: to educate community members about the critical importance of insects to our ecosystem. As insect declines are documented around the globe, it is essential that we collect data on insect population health and long-term trends here in Maine.


This project is funded by grants from the Maine Outdoor Heritage Fund and The Onion Foundation.

Onion Foundation

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