Grant: Alliance Grants

American eels (Anguilla rostrata) are imperilled throughout much of their native range due in part to mortalities resulting from encounters with hydroelectric infrastructure during downstream pre-spawning migrations towards marine environments. Population declines have been drastic enough that eels are listed as "Endangered" by the Province of Ontario and on the IUCN Red List. Reducing, avoiding, or eliminating physical encounters with potentially harmful infrastructure such as turbines have been identified as key components of population protection strategies, particularly when such encounters can be reduced via behavioural guidance technologies (i.e., guiding fish away from risky areas towards safer areas) that will not interfere with hydroelectric generation. Notably, artificial lights have demonstrated some promise at deflecting night-migrating eels away from illuminated fields, creating an opportunity to concentrate eels towards safe passageways or for efficient collection and transport. However, many light guidance studies have been conducted under captive, laboratory settings that lack obvious scaling potential to real-world applications or relied on field deployments coupled with downstream recaptures of eels and inferential determination of their movement patterns and pathways around light fields. We have partnered with Ontario Power Generation (OPG) and Hydro Quebec (HQ) as well as government collaborators to conduct a management-scale study to evaluate the effectiveness of light for guiding eels. With funding from OPG and HQ, two floating light arrays (217m and 120m length) will be installed in the St. Lawrence River immediately upstream of both the Iroquois Water Control Dam (ON) and the Saint-Louis-de-Gonzague Bridge in the Beauharnois Canal (QC). We will formally evaluate and quantify the effectiveness of artificial light at achieving guidance outcomes for the management and conservation of American eel populations encountering hydroelectric infrastructure. The team has been working on pilot and feasibility studies for nearly a decade in preparation for this unique, one-time opportunity to generate data needed to inform the protection of imperiled eels.