Sea-Run Brook Trout Studied in Wells, ME

Sea run brook trout, photo/New England Boating, Tom Richardson.
Sea run brook trout, photo/New England Boating, Tom Richardson.

In 2014, researchers at the Wells Reserve in Wells, Maine, trapped and counted sea-run brook trout in Branch Brook as part of an ongoing project to restore these native fish and the habitat they depend on. The researchers caught the fish as they moved from the estuary into the freshwater reaches of Branch Brook and ascended the restored fish ladder at the Water District filtration plant on Route 1.

Fin clips were collected from each trout to determine which fish are spending time at sea. The elements carbon and nitrogen exist in the environment in the form of different isotopes, which vary between marine and freshwater environments. When a brook trout spends time feeding at sea, the marine isotopes of these elements are absorbed and fixed in the fish’s body tissues. This non-lethal sampling is different from traditional isotopic analysis, which has relied on collection of the ear bone, known as the otilith. Researchers at Bates College will conduct the actual lab analysis of the isotopes.

Learn more about the Wells Reserve “salter” brook trout study here.