Miminegash River’s Strategic Wood Addition for Atlantic Salmon Habitat Recovery

This project aims to restore and build Atlantic salmon habitat in the Miminegash River, with a focus on riparian conservation, strategic wood addition, comprehensive monitoring efforts, and knowledge sharing. Key activities include:

Monitoring & Data Collection:

• Collecting the following data at pilot site for the following in high and low flow regimes: substrate; streambed profile; banks; floodplain; connectivity; average temperatures (general area); average flow velocity (general area); sheer stress.
• Concurrently monitor 10 sites for changes in temp, discharge, macroinvertebrates, geomorphology, riverbed and bank profiles (established 2024) covering the entire watershed, tracking large scale changes.

Conservation & rebuilding of Atlantic Salmon habitat:

• This Strategic Wood Addition (SWA) pilot, with guidance from PEI Salmon Advisory Committee is a first of its kind, and knowledge will be shared with 24 other watershed groups plus other groups relative to the cause (e.g. PEI Watershed Alliance, Atlantic Salmon Federation, DFO)
• An 875 meter river section on Miminegash River, incorporating 1st, 2nd, and 4th order streams will be provided SWA. Preliminary and baseline data already collected includes river riparian assessments(2024); baseline data on the data listed above will be collected at the pilot site (June 2026)
• Address limiting factor to Atlantic Salmon habitat (e.g. Impermeable strata (geology), poorly drained soils, high overland flows, high sheer stress, poor river geomorphology, lack of in-stream wood, lack of fish cover types).

• Increase Atlantic salmon habitat: reduce average flow velocity and sheer stress causing degradation to riverbed, displace concentrated high flows into floodplain and restore floodplain connectivity; improve the quality of river geomorphology, increase fish cover types.

Public Education: Community events, presentations, knowledge sharing with at least 26 non-governmental groups on PEI.

This project represents a comprehensive approach to river ecosystem restoration, monitoring, and community engagement, with the ultimate goal of ensuring a sustainable future for Atlantic salmon in the Miminegash River. The Miminegash River is now the only south-draining river in West Prince that supports Atlantic salmon.

Impermeable rock is defined as a type of rock that prevents the flow of fluids, often formed from fine-grained sediments with a high content of clay particles, resulting in a shale seal or caprock when deposited above permeable formations. The soil in the area is identified as poorly drained throughout 95% of this watershed. The Miminegash formation (Strata) consists essentially of orange-red mudstone with interbeds of fine- to very fine-grained wacke, thus impermeable, and visible in patches of the spawning habitat where sheer stress is too high to maintain adequate substrate.

A SWA pilot project supports the reduction of high velocity flows/sheer stress, while addressing the need for in-stream wood in the system, and restoration of suitable habitat for Atlantic Salmon that was identified as degraded due to heavy overland flows.

According to “A Renewed Conservation Strategy for Atlantic Salmon in PEI” (Guignon, 2019), it was  recommended that “the river be assessed to determine the extent of suitable salmon habitat and identify any limiting factors that need to be addressed”.

RMWI plans to continue to ensure that salmon have suitable access in and out of the river habitat as needed and will continue conservation monitoring efforts. The Miminegash River is a 4th-order system, with land use in the watershed consisting of 70.1% forest cover, 20.5% agricultural land, 4.9% developed areas, 4.4% wetlands, and 0.1% sand dunes. The return of Atlantic salmon to the Miminegash River highlights the presence of critical habitat that requires ongoing conservation and monitoring efforts.