River channel response to dam removals on the lower Penobscot River, Maine, United States

2020 ◽  
Vol 36 (9) ◽  
pp. 1778-1789 ◽  
Author(s):  
Mathias J. Collins ◽  
Alice R. Kelley ◽  
Pamela J. Lombard
Keyword(s):  
United States ◽  
River Channel ◽  
Channel Response ◽  
Penobscot River ◽  
Dam Removals

River channel response to short-term human-induced change in landscape connectivity in Andean ecosystems

Geomorphology ◽  
2005 ◽  
Vol 72 (1-4) ◽  
pp. 340-353 ◽  
Author(s):  
Veerle Vanacker ◽  
Armando Molina ◽  
Gerard Govers ◽  
Jean Poesen ◽  
Gerd Dercon ◽  
...  
Keyword(s):  
Landscape Connectivity ◽  
River Channel ◽  
Short Term ◽  
Channel Response

Managing Centrarchid Fisheries in Rivers and Streams

2019 ◽  
Keyword(s):  
Fish Assemblages ◽  
Growth Models ◽  
Stomach Contents ◽  
Smallmouth Bass ◽  
Ecological Change ◽  
Micropterus Dolomieu ◽  
River Herring ◽  
Penobscot River ◽  
Tidal Area ◽  
Dam Removals

<em>Abstract.</em>—Fish assemblages in Atlantic coastal rivers have undergone extensive ecological change in the last two and a half centuries due to human influence, including extirpation of many migratory fish species, such as river herring <em> Alosa </em>spp. and introduction of nonnative piscivores, notably Smallmouth Bass <em> Micropterus dolomieu</em>. Recently, dam removals and fish passage improvements in the Penobscot River, Maine, have allowed river herring to return to reaches of the river that have been inaccessible since the late 19th century. Alosine populations have increased and this trend is anticipated to continue. This may increase forage in the system which could potentially increase growth for Smallmouth Bass, the dominant piscivore. We examined the diet and growth of Smallmouth Bass collected from areas of the Penobscot River watershed with and without access to river herring as prey. We collected 765 Smallmouth Bass throughout 2015, examined the stomach contents of 573 individuals, and found notable differences in diet among three river reaches with common seasonal trends. Juvenile river herring composed an average of 19% (SE = ±6%) of stomach contents by mass from Smallmouth Bass collected in the freshwater tidal area but were rarely observed in the diets upstream. We used estimates from von Bertalanffy growth models to examine differences in growth among reaches and found that asymptotic length was the longest (425 mm TL) in the Tidal reach where access to river herring was unrestricted. We then used these data to predict changes to growth associated with increased access to juvenile river herring prey with bioenergetics models. Results indicated that substituting juvenile river herring for less energy-dense prey (e.g., invertebrates) may lead to increases in seasonal growth throughout the watershed as river herring populations continue to rebound in response to dam removal. Our results provide insight into the diet and growth of Smallmouth Bass in a large New England river, and provide a foundation for future work investigating unfolding changes to these characteristics following recent dam removals.

scholarly journals Are we ready for more dam removals in the United States?

2021 ◽  
Author(s):  
Farshid Vahedifard ◽  
Kaveh Madani ◽  
Amir AghaKouchak ◽  
Sannith Kumar Thota
Keyword(s):  
United States ◽  
The United States ◽  
Dam Removals

Rethinking Hydropower: The Economics and Politics of Privately Owned Hydropower in the United States

2020 ◽  
Author(s):  
Lynne Lewis
Keyword(s):  
United States ◽  
The United States ◽  
Fish Passage ◽  
Benefit Cost Analysis ◽  
20Th Anniversary ◽  
Kennebec River ◽  
Dam Removals ◽  
Benefit Cost ◽  
Privately Owned ◽  
Economics And Politics

2019 marked the 20th anniversary of the removal of the Edwards Dam in Augusta, Maine (USA). Edwards Dam was the first federally licensed hydropower dam to be denied relicensing, and the dam was removed for the purpose of restoring the 10 anadromous fish species that use the Kennebec River. Since that time, numerous other small dams have been removed in the United States. The relicensing process considers benefit-cost analysis, yet remains fundamentally flawed in the consideration of the benefits of dam removals and fish passage. Successful dam removals rely (mostly) on local efforts and outside analysis.

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