Avon River Fish Study

On Monday, August 17, 2026 staff from the Upper Thames River Conservation Authority (UTRCA) and members of the city of Stratford’s energy and environment committee gathered in the Avon River section just east of the St. Vincent Street dam to do a fish study. They conducted some electro fishing exercises to collect and record the fish species that were found in that section of the river.

This is the first time UTRCA has been able to survey this section of the river. Water levels are normally too high, but the temporary lowering of the John Street weir for bridge construction has provided a unique opportunity to see how the Avon responds under more natural, free-flowing conditions.

Approximately 17 different fish species were found including:

• Smallmouth Bass,
• Striped Shiner,
• White Sucker,
• Johnny Darter,
• Bluntnose Minnow,
• Common Shiner,
• Central Stoneroller,
• Greenside Darter,
• Blackside Darter,
• Black Bullhead and
• Northern Sunfish, Special Concern, Species at Risk.

Temporarily removing the fish barrier has reconnected upstream and downstream habitat, allowing fish to move more freely through the river. This connectivity is particularly important for fish that move upstream to spawning areas in the spring. Young White Suckers were captured during the survey, and local residents also reported seeing fish spawning in this area in the spring.

Lower water levels have also restored more river-like habitat. Water flowing over gravel, cobble and other river-bottom substrates increases turbulence and oxygenation and creates shallow, flowing habitat used by native species such as darters and stonerollers. At the same time, these conditions provide less of the slow, deep, pond-like habitat favoured by invasive Common Carp.

The presence of Northern Sunfish, a species of Special Concern, is particularly encouraging and shows that this urban section of the Avon is able to support species of conservation interest.

The temporary removal of the barrier provides a rare glimpse of what a more connected, free-flowing Avon River can support. The diverse fish community observed during the survey demonstrates the river’s resilience and highlights the potential ecological benefits of restoring natural flow, fish passage and river habitat.

For more information on the health of the Avon River, read the UTRCA’s 2022 Wathershed Report Card here.