Angler Science

Angler Science defined:

“Anglers gathering scientific information about the fish and the places they love”

Citizen science is a rapidly expanding field where millions of participants each year gather data on hundreds of topics ranging from the weather, to water quality, threatened and endangered species, and such far off topics as the shape of galaxies. Trout Unlimited members have been gathering data on water quality and fish populations since the organization was established in 1959 but only recently have we expanded the opportunities for anglers and actively marketed the potential for anglers to assist in the science-based management of trout and salmon and their habitats.

In 2016, TU scientists wrote a feature article in the Journal of Soil and Water Conservation about some of our larger Angler Science projects and how participation among anglers produces more knowledgeable advocates for better stewardship of coldwater fisheries resources. As demonstrated in this Angler Science video, TU's grassroots members grow in strength and capacity when they partner with management agencies to help fill data gaps and improve our understanding of trout, salmon, and their habitats.

Check out the following opportunities for anglers to contribute to the scientific understanding of trout and salmon conservation.


Environmental DNA



Aquatic species can be difficult to detect using traditional methods (angling, electrofishing, netting), but sampling for environmental DNA (eDNA) allows us to detect a species without the need to capture or handle the fish. The concept is simple: biological material is continually shed by aquatic organisms and suspended in the water column, and can be captured and concentrated as water is washed across a laboratory filter. DNA isolated from this material can later be used to detect the presence or absence of one or more species of interest with high accuracy (assuming a DNA ‘bar code’ marker has been developed for that species, as it has for many trout). With proper volunteer training, this approach provides a relatively simple way for TU volunteers to contribute to our science and conservation efforts in many ways. Environmental DNA collections can be used to refine our basic understanding of species distributions, especially for rare species which can be particularly difficult to detect with other methods (e.g., we are already contributing to a Forest Service-led effort to sample eDNA of bull trout in the western US, see: It is also useful for determining the effectiveness of common conservation actions we undertake in various TU programs. For instance, eDNA can verify a species of interest is now using habitat that has been recently connected or restored; that efforts to eradicate non-native species were successful (i.e., the non-native species is no longer present) before moving forward with reintroduction of a native species; or whether or not an aquatic nuisance species is present in trout waters.

See for a (non-exhaustive) list of DNA markers available and a sampling protocol.

Staff contact: Helen Neville


Steelhead Angler Science


Perhaps no fish in the Pacific Northwest is more revered and sought after than the wild steelhead, and the angler science programs of TU are well positioned to harness the passion and sense of responsibility in steelhead anglers. While state agencies work hard to monitor trends in wild steelhead abundance and distribution, many data gaps remain. A well trained dedicated group of angler scientists could help fill some of these gaps, providing needed information useful to guide conservation actions and shape management strategies. Some work is underway, such as efforts to count steelhead redds on Oregon’s Salmonberry and Molalla Rivers. Various aspects of stream habitat, including stream channel complexity, riparian features, water temperature, and instream cover, are important to steelhead health. Information on habitat, particularly when coupled with redd count or snorkel survey data, can be used to help determine why steelhead use particular areas within a watershed and to predict how conservation actions in riparian areas and stream channels may affect steelhead abundance and distribution. Data from Steelhead redd counts can be used to determine the spatial and temporal distribution of breeding and population abundance, and there are numerous opportunities for redd counts to provide new information that would not otherwise be available without citizen scientists. Our goal is to train a league of anglers to collect and report important data on steelhead populations and their habitat in a systematic and repeatable fashion, according to strict scientific principles. For more information, check out our steelhead angler science brochure.

Staff contacts: John McMillan, Kyle Smith, Nick Chambers, Jack Williams


Stream Temperature Monitoring


Trout prefer cold water, often less than 65°F, and stream temperature has a strong influence on their well-being. TU restoration projects often target improving stream temperatures, and keeping a record of temperature variability and trends can be an important tool to help confirm the success of these efforts or identify where further work is needed. Waterproof data logging thermometers offer a simple, affordable means to fill this need. Check out our Stream Temperature Monitoring Handbook. TU also works closely with US Forest Service scientists and their NorWeST stream temperature network. Their website includes loads of suggestions for help in starting a stream temperature project and in interpreting results.

Also consult TU's Stream Temperature Monitoring Resources Page.

Staff contacts: Kurt Fesenmyer or Dan Dauwalter in the West and Jake Lemon in the East


Discovering Didymo’s Distribution


Didymo is a small diatom that causes a big problem: large algae mats that smother stream substrates and reduce fishing quality. Scientists used to believe that Didymo was an invasive species but the latest data suggest that this diatom may have a broader natural distribution. Our Discovering Didymo’s Distribution project is an effort to get to the bottom of this puzzle and determine the native range of this diatom and under what conditions it tends to produce stalks and algal mats. TU is working with Dr. Brad Taylor and his students at North Carolina State University to fully understand what is going on. Anglers collect algal samples from stream cobbles, the samples are mailed to North Carolina State University in prepaid envelopes, and as samples are processed info is posted at the Didymo website on campus. Habitat photos can be taken at algal sample locations and uploaded to iNaturalist following this instruction guide. Our pilot project in North Carolina began in 2016 and is likely to spread to other states in the near future. TU Canada also is working on this project through their volunteers and the University of Calgary.

A summary of the project from TU Canada can be found here

Staff contact: Matt Barney


Culverts and Road Stream Crossing Assessments


Our objectives through assessing road stream crossing infrastructure are threefold: first to evaluate a stream’s aquatic organism passage, second to understand its geomorphic compatibility with restoration work, and lastly to evaluate its hydrologic vulnerability. Ultimately, our desire is to reconnect trout habitat and at the same time help communities become more “flood resilient”.

The New England Culvert Project (NECP) has been working with TU Chapters and state agencies across the northeast to field assess road stream crossings on a landscape scale. Large drainages, such as the Deerfield River in MA and VT and the Ammonoosuc and Piscataquog Rivers in NH, have been completely evaluated for the metrics mentioned above. This information is then shared throughout the watershed community in an effort to help towns, with assistance from the NECP team, proactively restore vulnerable infrastructure. The Piscataquog River project, encompassing 218 square miles, utilized over 800 hours of TU Chapter volunteer time to assess over 525 culverts. TU Chapter volunteers are trained, supplied with the necessary gear, and assisted in the field by TU National staff. For more information on how to help create a project in your community, contact Colin Lawson of our Eastern Conservation Staff.

Staff contact: Colin Lawson


Eastern Shale Gas Monitoring


Development and transmission of shale gas threaten stream systems from Pennsylvania to West Virginia with potential contaminant spillage and erosion and sedimentation issues. Through Trout Unlimited's Pennsylvania Coldwater Conservation Corps, members there have been actively monitoring streams for signs of shale gas and pipeline development, including changes in basic water quality parameters. Meanwhile, volunteers in West Virginia and Virginia are monitoring areas currently experiencing shale gas and pipeline development, as well as collecting baseline data in areas which are likely to be developed in the future. Catch up on their activities on the Eastern Shale Gas Monitoring Program page.

Additional info:

  • Check out a new short film that highlights those who guard our waters.
  • An interactive story map lets you explore volunteer pipeline monitoring efforts.
  • The Crowd and the Cloud is 4-part PBS series about citizen science that features Trout Unlimited's shale gas monitoring volunteers.


Staff contact: Jake Lemon


Stream Water Quality


Trout Unlimited believes that angler-based, citizen science water quality monitoring efforts will play a large role in the preservation of coldwater fish species and their habitats as well as ensure years of recreational opportunities for future generations. To this end, TU has developed a Water Quality Manual to provide chapters, members, anglers, outdoor enthusiasts, and others interested in water quality with the information necessary to monitor their local streams. Unfortunately, many state agencies and environmental organizations simply do not have the resources to adequately monitor our nation’s bountiful flowing freshwater resources. Trout Unlimited chapters, members, and other volunteers can help fill information gaps by collecting water quality information and collaborating with state agencies, environmental organizations, and local universities to promote the health of rivers and freshwater ecosystems and ensure the enjoyment of these resources for generations to come. Learn more about monitoring water quality in your local area in TU's Water Quality Manual.

Staff contact: Jack Williams


River’s Calendar


Trout Unlimited, the University of Massachusetts and partners are developing the River’s Calendar, a community science program in which trout anglers record the seasonal timing of aquatic insect emergence, fish movements and riparian plant flowering while fishing. This is another TU Angler Science project that works through the iNaturalist observation platform. You can follow the River’s Calendar project and participate through iNaturalist. This information will be translated into detailed calendars of hatches and other riparian life for each river studied – suitable for use by anglers and other river recreationists. This information will also form the basis for an objective, science-based examination of the phenology of streams – the timing of life cycles and how they are influenced by environmental and climate change. Check out the River's Calendar Starter Kit, which includes field guides for select aquatic insects in Massachusetts and Oregon.

Staff contact: Matt Barney


Angler Drought Survey (ADS)


Much of the Western United States has experienced intense drought for the last several years leaving small headwaters stagnant to dry and trout stressed or stranded. Trout Unlimited has partnered with Deep Creek Fly Fishers and the California Department of Fish and Wildlife to conduct angler drought surveys in California. The project is piloting in the San Bernardino and San Jacinto Mountain ranges located in the San Bernardino and San Jacinto National Forests. We need anglers to collect basic data while they are out fishing, including location, trout species seen/caught, stream flow (simple method instructions provided), and water temperature. These data will help inform state agencies of stream conditions so that they can better protect and manage coldwater fish species.

Download the ADS training presentation and datasheet.

Staff contact: Jessica Strickland




TroutBlitz is a project aimed at cataloging the rich diversity of North America’s native salmonids, including trout, steelhead, charr, whitefish, and salmon. Through photography and angling, TU members can help document the presence of native and introduced coldwater fishes. Using iNaturalist, anglers can upload geo-referenced photos of fishes or their habitats for a variety of purposes including, documenting the presence of native or introduced fishes for management agencies, determining the effectiveness of restoration or reintroduction projects, or to build a library of native salmonids across their geographic range. Check out TroutBlitz on iNaturalist!

Staff contact: Matt Barney


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