The consequences of dam passage for downstream-migrating American eel in the Penobscot River, Maine

2021 ◽  
pp. 1-12
Author(s):  
Matthew A. Mensinger ◽  
Erik J. Blomberg ◽  
Joseph D. Zydlewski
Keyword(s):  
Acoustic Telemetry ◽  
Survival Rates ◽  
Anguilla Rostrata ◽  
American Eel ◽  
Cumulative Mortality ◽  
Low Flows ◽  
Risk Of Mortality ◽  
Hydropower Dams ◽  
Penobscot River

American eel (Anguilla rostrata) often pass hydropower dams during adult spawning migrations. We conducted a 4-year acoustic telemetry study that characterized passage risks through two dams (West Enfield and Milford) in the Penobscot River, Maine, USA. We released tagged fish (n = 355) at two sites, estimated survival and delay under variable river conditions, and compared performance among dammed and free-flowing river sections. Survival rates (standardized per river kilometre, rkm) were lower at West Enfield (Φrkm = 0.984 ± 0.006 SE) and Milford (Φrkm = 0.966 ± 0.007 SE) compared with undammed River sections (Φrkm = 0.998 ± 0.0003 SE). Cumulative mortality was 8.7% (4.4 km) and 14.2% (5.5 km) through dammed sections and 8.7% throughout the rest of the river (58.1 km). Fish that already passed an upstream dam incurred higher downstream mortality compared with individuals without passage experience. Additionally, fish endured long delays at dams, and >10% of fish were delayed >24 h. Low flows exacerbated the risk of mortality and delay. These results offer evidence for direct, latent, and sublethal consequences of dam passage for migrating eels.

Relating American Eel Anguilla rostrata abundance to environmental DNA concentration in the Bronx River

2021 ◽  
Author(s):  
Sam C. Chin ◽  
John Waldman ◽  
Mike Bednarski ◽  
Merry Camhi ◽  
Jake LaBelle ◽  
...  
Keyword(s):  
Environmental Dna ◽  
Anguilla Rostrata ◽  
American Eel ◽  
Dna Concentration ◽  
Bronx River

scholarly journals American eel,Anguilla rostrata, growth in fresh and salt water: implications for conservation and aquaculture

2009 ◽  
Vol 16 (4) ◽  
pp. 306-314 ◽  
Author(s):  
H. M. LAMSON ◽  
D. K. CAIRNS ◽  
J.-C. SHIAO ◽  
Y. IIZUKA ◽  
W.-N. TZENG
Keyword(s):  
Salt Water ◽  
Anguilla Rostrata ◽  
American Eel

scholarly journals Assessing demographic effects of dams on diadromous fish: a case study for Atlantic salmon in the Penobscot River, Maine

2015 ◽  
Vol 72 (8) ◽  
pp. 2423-2437 ◽  
Author(s):  
Julie L. Nieland ◽  
Timothy F. Sheehan ◽  
Rory Saunders
Keyword(s):  
Atlantic Salmon ◽  
Performance Metrics ◽  
Survival Rates ◽  
Population Viability Analysis ◽  
River System ◽  
Diadromous Fish ◽  
Viability Analysis ◽  
Penobscot River ◽  
Passage Efficiency ◽  
Demographic Effects

Abstract Dams are a major contributor to the historic decline and current low abundance of diadromous fish. We developed a population viability analysis to assess demographic effects of dams on diadromous fish within a river system and demonstrated an application of the model with Atlantic salmon in the Penobscot River, Maine. We used abundance and distribution of wild- and hatchery-origin adult salmon throughout the watershed as performance metrics. Salmon abundance, distribution to upper reaches of the Penobscot watershed, and the number and proportion of wild-origin fish in the upper reaches of the Penobscot watershed increased when dams, particularly mainstem dams, were removed or passage efficiency was increased. Salmon abundance decreased as indirect latent mortality per dam was increased. Salmon abundance increased as marine or freshwater survival rates were increased, but the increase in abundance was larger when marine survival was increased than when freshwater survival was increased. Without hatchery supplementation, salmon abundance equalled zero with low marine and freshwater survival but increased when marine and freshwater survival rates were increased. Models, such as this one, that incorporate biological, environmental, and functional parameters can be used to predict ecological responses of fish populations and can help evaluate and prioritize management and restoration actions for diadromous fish.

scholarly journals Behavioural guidance of yellow-stage American eel Anguilla rostrata with a light- emitting diode device

2018 ◽  
Vol 35 ◽  
pp. 159-168 ◽  
Author(s):  
CK Elvidge ◽  
MI Ford ◽  
TC Pratt ◽  
KE Smokorowski ◽  
M Sills ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Anguilla Rostrata ◽  
American Eel ◽  
Light Emitting

Artificial maturation, fertilization, and early development of the American eel (Anguilla rostrata)

2010 ◽  
Vol 88 (11) ◽  
pp. 1121-1128 ◽  
Author(s):  
K. Oliveira ◽  
W. E. Hable
Keyword(s):  
Early Development ◽  
Anguilla Rostrata ◽  
Sargasso Sea ◽  
American Eel ◽  
Important Species ◽  
Vitro Fertilization ◽  
Commercially Important ◽  
Elusive Species ◽  
American Eels

Spawning for the American eel ( Anguilla rostrata (Le Sueur, 1817)) takes place in secretive locations within the Sargasso Sea, which has thus far prevented investigations of gametogenesis and early development in this ecologically and commercially important species. Attempts to induce maturation and reproduction in this species have been few and have produced limited results, with a single report of the production of gastrula-stage embryos. Here we report the successful maturation of female American eels. Maturation occurred within 13 weeks and ovulation was induced with a single injection of 17α,20β-dihydroxy-4-pregnen-3-one (DHP). Following in vitro fertilization, embryogenesis through hatching was observed and larvae were maintained for up to 6 days. We show that a crucial factor for successful fertilization is the stage of the oocyte at the time of induced ovulation. Oocytes that had not reached the migratory nucleus stage, or had passed this stage, were not successfully fertilized. These findings demonstrate that American eel can reproduce in the laboratory and previously untestable hypotheses pertaining to the developmental biology of this elusive species can now be explored.

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