Life Sciences Commons^™

Effects Of Dam Removal On Assemblage Composition And The Interactions Of Fishes In The Penobscot River, Maine, Jonathan Watson

Electronic Theses and Dissertations

Dams and their impoundments disrupt river habitat connectivity to the detriment of migratory fishes. Removal of dams improves riverine connectivity and lotic habitat which benefits these fishes along with resident fluvial specialist species. Restoration efforts on the Penobscot River (Maine, USA) are among the largest recently completed in the United States, and include the removal of the two lower-most dams and improvements to fish passage at several remaining barriers. Here we describe initial and potential future changes to fish communities in the Penobscot River associated with these restoration efforts.

We assessed fish assemblages in the mainstem river and several major …

Exploring The Threats Of Dams And Ocean Conditions: In-River Movements And Ocean Growth Of Atlantic Salmon (Salmo Salar) From Maine's Rivers, Lisa K. Izzo

Electronic Theses and Dissertations

Substantial declines of anadromous Atlantic Salmon Salmo salar have occurred throughout the range of the species, with many populations at the southern extent of the distribution being extirpated or endangered. While Maine is the last state in the country where adult Atlantic Salmon return to rivers each year to spawn, numbers have decreased dramatically in recent decades, with typically less than 2,000 spawners returning to all Maine's rivers combined. The complex life history of this species, which involves a juvenile freshwater phase followed by a marine phase that can last one to five years before returning to freshwater to spawn …

Characterizing Fish Assemblage Structure In The Penobscot River Prior To Dam Removal, Ian Andrew Kiraly

Electronic Theses and Dissertations

The Penobscot River drains the largest watershed in Maine, and once provided spawning and rearing habitats to at least 11 species of diadromous fish. The construction of dams blocked migrations of these fish and likely changed the structure and function of fish assemblages throughout the river. Further alteration to fish assemblage structure likely occurred as a result of habitat fragmentation and alteration. The proposed removal of two main-stem dams, improved upstream fish passage at a third dam, and construction of a fish bypass on dam obstructing a major tributary is anticipated to increase passage of diadromous and resident fishes. To …