by Dan Boward
They brave cold, often frigid conditions. They defy gusty winter blasts. They’re dedicated, focused and intent on getting the job done. Each spring, from the Appalachian Plateau to the lower Eastern Shore, a photo showing young Streamwaders spending an afternoon sampling for aquatic invertebrates.scores of them emerge from their warm and cozy cars to wade into the icy waters of Maryland’s freshwater streams - nets, buckets and Global Positioning System (GPS) Units in hand.

Who are these brave and enthusiastic souls? They are volunteers with the Department of Natural Resources (DNR) Stream Waders Program embarking on an annual wade-in.

Since 2000, the staff of DNR’s Monitoring and Non-Tidal Assessment unit have been recruiting and training adult volunteers to gather stream-quality data. Their volunteer work supports the Maryland Biological Stream Survey (MBSS), DNR’s professional statewide stream sampling program.

Because MBSS crews cannot examine every stream in every watershed, these stream waders go a long way in helping bridge the gaps. MBSS crews sample fish, reptiles and amphibians and collect data on water chemistry and physical habitat, while Stream Waders sample aquatic invertebrates - excellent indicators of stream quality - and collect stream site information. Stream Wader sites are chosen from smaller sub-watersheds, and their samplings provide localized data that are particularly useful to area governments and watershed organizations.

Aquatic Invertebrates
Cool Creatures from the Not So Deep

image of a mayfly..Mayflies have survived mostly unchanged for 350 million years; they were around before dinosaurs existed.Freshwater aquatic invertebrates live on rocks, logs, debris and aquatic plants during some period of their life. Scientifically speaking, they are freshwater animals without a backbone that are larger than one-half millimeter (about the size of a pencil point). The most commonly encountered ones include insects such as mayflies and stoneflies. Yes, those scary-looking dragonflies you sometimes see near ponds and streams are aquatic invertebrates too. The group also includes crustaceans such as crayfish, mollusks such as clams and snails, and worms.

image of a dragonfly..Dragonflies are fantastic fliers, able to hover, fly backwards, swerve, dive and quickly change directions to catch flying insects; they often follow regular flight paths each day.These little critters are great for assessing stream health for several reasons. Unlike fish, they are fairly immobile, so they are less able to escape the effects of sediment and other pollutants that reduce water quality. Therefore, they can give us reliable information on water and habitat quality in streams. Aquatic invertebrates represent an extremely diverse group of animals, and the large number of species show a wide range of responses to stressors such as organic and toxic pollutants and sediment. Lastly, many of them are long-lived (up to three years), allowing detection of past pollution events such as pesticide spills and illegal dumping. Perhaps best of all, these animals are found in almost every water body and are quite easy to sample. They are also fairly easy to identify.

image of a stonefly..Because most are found walking on stones near water, they are called stonflies.So stop by your local stream, pick up a submerged rock or stick and look at what’s crawling on it. You may be surprised. Aside from being fish food, these little critters can provide lots of information on the health of the stream and its watershed.

Grab Your Hip Boots
How does the Stream Waders program work? Each February, MBSS biologists hold several all-day training sessions across the state. This training covers aquatic invertebrate sampling protocols, the proper use of a GPS unit, how to accurately take stream channel measurements, and procedures for obtaining landowner permission. The volunteers then divide up into teams, and each team is given the necessary maps and equipment and sent on its way. Actual stream sampling takes place during March and April. The highest priority sampling sites are those selected by local governments or watershed organizations, but volunteers are also able to choose sampling sites that are of interest to them.

Take Plenty of Notes (use waterproof markers)
How exactly is the Stream Waders data used? Local governments in Frederick, St. Mary’s, Anne Arundel and Worcester Counties use both Stream Waders and MBSS data to characterize stream conditions for watershed health profiles. The results help direct restoration money toward waterway improvements likely to have the greatest impact.

Organizations such as the Ridge and Valley Stream Keepers of Southern Pennsylvania and Western Maryland, the Magothy River Association in Anne Arundel County, and the Port Tobacco Conservancy in Charles County collected data from over 80 sites to help develop watershed management plans. Such data has also been used to evaluate stream impacts from a fly-ash facility in Charles County, a logging operation in St. Mary’s County and a housing development in Baltimore County.

The Maryland Department of the Environment (MDE) uses Stream Waders data to help assess the quality of the state’s non-tidal wetlands. Lastly, since Stream Waders may choose sampling sites close to or on their property, the volunteers themselves may also make use of the data.

Celebrate Your Efforts
Stream Waders has been a big success, much of which can be attributed to the efforts of an active pool of citizens concerned about environmental health and the condition of their local streams. More than 600 volunteers have logged more than 15,000 hours and sampled roughly 2,100 stream sites since the program started three years ago. It’s quite a task because the average number of Stream Wader sites per medium-sized watershed is 23; compare this to MBSS crews that complete more exhaustive assessments at an average of nine sites per watershed. The Stream Waders program fits so seamlessly into the MBSS that volunteer samplers truly are "citizen scientists".

Why are these dedicated citizens willing to work so hard for this cause? In a recent opinion poll of its volunteers, most said that they joined Stream Waders to learn about the environment. Others said they joined to support DNR stream monitoring efforts, to learn aquatic invertebrate sampling methods and to make new friends.

These survey results offer proof positive that DNR has put together an effective environmental stewardship program, especially since many of the volunteers told us they’re sharing what they’ve two photos showing that rain, snow, sleet or hail...Nothing stops the Streamwader volunteers.learned with family, friends and neighbors. High school and college teachers regularly complete the training, which further circulates this knowledge. These volunteers do so much more than just gather stream data - they enhance their understanding of the natural world and ultimately become better environmental stewards.

So, next time you’re out driving on a blustery spring day and you come across a band of smiling folks with bug nets, buckets and GPS units heading toward a stream, stop, say hello and offer them a cup of hot coffee. Now you know why they’re out there, what they’re looking for and how they are helping DNR learn about the health of Maryland’s streams.

By the way, the bug nets used by Stream Waders are one-size-fits-all, so if you’re interested in joining, send us an email at To learn more about the program, visit

Dan Boward...
directs the Stream Waders Program for DNR's Monitoring and Non-Tidal Assessment Division. He has been involved in stream and river monitoring in Maryland at DNR and MDE for the past 18 years. He has a BS degree in Zoology from the University of Maryland and a MS in Environmental Science from Johns Hopkins University. He also provided the photos for this article.

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