Sunrise over HCFF Strawberry Fishout - photo by club member Jennifer Raney

Fly fishing the Weber River

Protecting the Weber River Green Sucker Helps Protect Trout Fishing

Understanding the decline of this native fish may help protect the food web,
aquatic insects, and river ecosystem that support the Weber River trout fishery.

The Weber River Green Sucker is a native fish species experiencing a severe reproductive bottleneck.
Very few young fish are surviving to adulthood, and researchers now suspect that a deficiency in thiamine (vitamin B1) may be playing an important role.

Green Sucker from the Weber River
The Weber River Green Sucker is a native fish species that may provide important clues about river ecosystem health.

Why Trout Anglers Should Care

At first glance, protecting a native sucker species may not seem directly connected to fly fishing.
But researchers believe the Green Sucker may be helping maintain important ecological functions within the Weber River.

The same river conditions that support healthy Green Sucker populations also influence:

  • Aquatic insect productivity
  • Water quality and nutrient balance
  • Food web stability
  • Habitat complexity
  • Overall trout river health

Scientists studying the Weber River specifically note that Green Suckers may function as ecosystem engineers, and understanding their ecological role could help managers better maintain desirable trout fisheries.

Brown Trout from the Weber River
Researchers are also testing Brown Trout thiamine levels because food-web deficiencies can affect multiple fish species.

A Warning Sign in the River Food Web

Newly hatched Green Sucker fry from the Weber River have shown symptoms consistent with Thiamine Deficiency Complex (TDC), a condition caused by insufficient vitamin B1.

Thiamine is essential for proper fish development. Without enough of it, fry may experience neurological problems, abnormal swimming behavior, developmental failure, and early mortality.

Researchers observed that affected fry improved after receiving thiamine baths, strongly suggesting that thiamine deficiency may be limiting survival in the wild population.

Researchers conducting Weber River fisheries work
Fisheries researchers are studying thiamine availability throughout the Weber River food web.

Understanding the Weber River Food Web

The research effort is being led by Dr. Chad Teal of the U.S. Geological Survey Utah Cooperative Fish and Wildlife Research Unit and Utah State University in partnership with the Utah Division of Wildlife Resources.

The project investigates whether nutritional deficiencies are originating lower in the food web — including algae, periphyton, bacteria, and aquatic invertebrates.

Because trout depend heavily on aquatic insects and healthy aquatic productivity, understanding these lower trophic levels benefits far more than just one native fish species.

  • Green Sucker egg thiamine analysis
  • Brown Trout muscle thiamine testing
  • Macroinvertebrate sampling
  • Periphyton and algae analysis
  • Habitat quality assessment
  • Food web characterization

Healthy Native Fish Communities Support Healthy Trout Rivers

Native fish conservation and trout fishing are not competing goals. In many western rivers, healthy native fish populations indicate stronger overall ecosystem function.

Rivers with functioning food webs, balanced nutrient cycling, productive insect communities, and healthy habitat complexity are more resilient and better able to support quality trout fisheries.

Protecting the Green Sucker may ultimately help biologists identify broader ecosystem problems before they further impact the Weber River trout fishery.

Funding Priorities

The full 2.5-year research effort totals approximately $130,968, with state and federal partners already covering the majority of the project costs.

The requested support would help expand field work, food-web analysis, and fisheries training:


Priority
Amount
Undergraduate Fisheries Technician $3,500
Expanded Invertebrate Thiamine Testing $2,000
CERC Travel & Training for Aric McKinney $1,000
CERC Travel & Training for Undergraduate Technician $1,000
Total Requested Support $7,500

High Country Fly Fishers Logo

High Country Fly Fishers Conservation Support

High Country Fly Fishers has long supported conservation projects that protect trout fisheries, improve river health, and strengthen Utah’s aquatic ecosystems.

In support of this effort, HCFF President Eric Luna introduced a proposal requesting that the High Country Fly Fishers Board of Directors approve funding toward the Weber River Green Sucker research project being conducted by Utah State University, the U.S. Geological Survey, and the Utah Division of Wildlife Resources.

The proposed HCFF contribution would help expand:

  • Field fisheries technician support
  • Aquatic invertebrate thiamine testing
  • Graduate and undergraduate fisheries training
  • Food web analysis related to trout river health

The total research project budget is approximately $130,968, with state and federal agencies already contributing the vast majority of project funding. The proposed HCFF $7,500 contribution would help fill targeted gaps that directly strengthen the field and laboratory work.

Bruce Pope formally seconded the motion and emphasized the importance of the Green Sucker as an indicator species whose health may reflect the overall ecological condition of the Weber River system and its trout fishery.

“The Weber ‘green sucker’ is critical to the Weber River's health by serving as a key algae grazer, reducing nutrient buildup, and acting as a vital food source for trout.”— Bruce Pope

Supporting this research reflects HCFF’s commitment to science-based conservation and the long-term protection of Utah trout fisheries and river ecosystems.

Protecting a Native Fish Helps Protect a Trout River

The Weber River Green Sucker may be warning us about deeper problems within the river ecosystem.

Understanding why this species is struggling could improve conservation strategies benefiting aquatic insects, native fish, Brown Trout, and the future of fly fishing on the Weber River.

Supporting this research is an investment in the long-term health of one of Utah’s important trout rivers.

Learn More

References

  1. Teal, C. & McKinney, A. Protecting Green Sucker in the Weber River,
    Utah State University Quinney College of Agriculture and Natural Resources.
  2. Teal, C. Thiamine Availability in the Weber River and its Implications for Native Fish Conservation and Sportfish Management,
    U.S. Geological Survey Utah Cooperative Fish and Wildlife Research Unit.
  3. Harder et al. 2018.
    Thiamine Deficiency in Fishes: Causes, Consequences, and Potential Solutions.
  4. Webber, Thompson, and Budy. 2012.
    Status and Structure of Two Populations of the Bluehead Sucker in the Weber River, Utah.