Undercurrent: The Alden Blog


Industrial fluid dynamics insights

Benjamin Lenz
Benjamin Lenz
Mr. Lenz is responsible for developing and managing projects that evaluate natural resource impacts from electric generation facilities. Currently, Mr. Lenz is involved in trout bypass survival and efficiency studies, instream flow assessments, American eel passage feasibility evaluations, and a river herring upstream passage siting telemetry study in New England. He is also a team member for Federal Energy Regulatory Commission (FERC) relicensing of small hydroelectric facilities in Rhode Island. 

Eel Shining to Locate Upstream Passage Routes
Searching for eels is an activity reserved for those who like to stay up late. Only under the cover of darkness is one able to have the best chance to find these nocturnal fish. Surveying for American eels, Anguilla rostrata, with lanterns at night or “shining” is a common method to document their presence in rivers across eastern North America. Juvenile American eels often congregate downstream of obstacles that block their upstream movement (eels are catadromous fish, meaning adults spawn in saltwater and the young move into freshwater to rear and mature before returning to the marine environment to complete the reproductive cycle). Hydroelectric dams are common impediments to upstream migrants along river courses. Finding optimal areas to establish passage routes for eels to move upstream is a primary reason to shine for eels.  Eels, being a fish, become more active as the water temperature rises. When the temperature is above 10 degrees C, which generally occurs from May to October in New England, eels of all ages and sizes become more active. The recently born glass eels, (so called ...