RICHMOND, Va. (WRIC) — A so-called “fish passage” at Bosher’s Dam on the James River is protecting eels during their migration to the ocean.

American eels spend most of their lives in freshwater streams like the James River, but begin and end their lives in the Sargasso Sea in the Atlantic Ocean, according to Alan Weaver, the Fish Passage Coordinator for the Virginia Department of Wildlife Resources. These eels live between 15 and 20 years, and then end their life cycle by migrating back to the ocean to spawn.

However, the Bosher Dam usually blocks the eels’ path upstream. A “fish passage” — a water pathway made of a narrow construction of chambers — this gives the eels and many other fish species a way to swim around or above the dam so they can continue their path of migration.

During their lifespan, American eels are an important part of the ecosystem due to their role as both predator and prey. Eels keep other fish and aquatic animal populations under control, and, in turn, they also serve as a food source for birds and other fish. By assisting their path to migration, these passages aim to rebuild declining numbers in the American eel population and maintain their important place in the ecosystem.