ALNA

On a recent Saturday morning, more than 30 participants gathered at Head Tide dam in Alna for the Sheepscot Valley Conservation Association’s Migratory Fish Day.

Participants in the event learned about migratory fish native to the river and estuary, particularly the Atlantic salmon, but also alewives, lamprey and American eel.

Josh and Jen Noll, field technicians from the Maine Department of Marine Resources, checked rotary screw traps — devices that live-trap fish in a waterway and contain them in a holding area — that are set on the river from April to June.

Trapped fish are counted, measured and marked in an effort to monitor the population and health of young Atlantic salmon headed out toward the Gulf of Maine. Jason Overlock, a Maine DMR fisheries biologist working in the state’s salmon program, answered questions about the program and salmon run.

Alewives and lamprey, also caught in the traps, are anadromous fish that spawn in freshwater. The American eel spawns in the Sargasso Sea and the juvenile eels, called elvers, return from the Atlantic to the rivers.

Following the demonstration, participants attended a presentation by Claire Enterline, a DMR marine scientist, about the ecology of the Sheepscot River and its wildlife.

“What was most interesting to probably everyone in the room,” said Kristin Pennock, administrative assistant at SVCA, “was the elaborate interrelationship among all of the species of migratory fish and some of the resident species as well.”

A second Migratory Fish Day will take place at 10 a.m. Sunday, June 1, at the Coopers Mills dam and fishway in Whitefield.

The Sheepscot Valley Conservation Association is a nonprofit land trust and advocacy group formed in 1969, which currently protects more than 3,600 acres of land. For additional information, call 586-5616 or visit www.sheepscot.org.