Evaluating Small Barrier Removal and Passage Improvement Scenarios to Enhance Diadromous Fish Restoration in the Penobscot Basin, Maine

摘要

The Penobscot River Restoration Project (PRRP) offers some unique opportunities to reconnect 12 native diadromous species with historic habitats and restore associated ecological functions. In particular, alewives Alosa pseudoharengus are absent fromthe drainage with the exception of two tributaries of the Penobscot estuary: the Souadabscook Stream and the Orland River. While the PRRP will substantially improve passage conditions for diadromous fish in the Penobscot Basin, it is in no way a "silverbullet" for ecosystem restoration of the Penobscot Basin. There are roughly 100 small dams and other fish passage barriers in the Penobscot Basin that will prevent some diadromous species from gaining access to historic habitats after the implementationof the PRRP. Many other passage impediments will need to be addressed to realize the full potential of the PRRP. We assessed the restoration potential for alewives in the major sub watersheds using a novel, yet simple, geographic information system-based approach to help prioritize restoration efforts in the Penobscot basin.