Temporally stable population-specific differences in run timing of one-sea-winter Atlantic salmon returning to a large river system

Bacterial kidney disease was presumptively identified in each of 25 hatchery-reared juvenile salmon (Salmo salar) but in only 2 of 235 wild juveniles in the Margaree River system. Apparently spread of disease from the hatchery to wild salmon in the river is very gradual.

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

ICES Journal of Marine Science ◽

10.1093/icesjms/fsv083 ◽

2015 ◽

Vol 72 (8) ◽

pp. 2423-2437 ◽

Cited By ~ 17

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.

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A comparison of modeling techniques to predict juvenile 0+ fish species occurrences in a large river system

Ecological Informatics ◽

10.1016/j.ecoinf.2011.05.001 ◽

2011 ◽

Vol 6 (5) ◽

pp. 276-285 ◽

Cited By ~ 24

Author(s):

J. Leclere ◽

T. Oberdorff ◽

J. Belliard ◽

F. Leprieur

Keyword(s):

Fish Species ◽

River System ◽

Large River ◽

Modeling Techniques ◽

Species Occurrences

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Relationship of upstream migrating adult Atlantic salmon (Salmo salar) and stream discharge within Catamaran Brook, New Brunswick

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f07-032 ◽

2007 ◽

Vol 64 (3) ◽

pp. 563-573 ◽

Cited By ~ 15

Author(s):

Sean C Mitchell ◽

Richard A Cunjak

Keyword(s):

Body Size ◽

Atlantic Salmon ◽

New Brunswick ◽

Salmo Salar ◽

Predictive Ability ◽

River System ◽

Low Flow ◽

Stream Discharge ◽

Atlantic Salmon Salmo Salar ◽

Adult Abundance

Stream discharge has long been associated with abundance of returning adult spawning salmonids to streams and may also affect body size distribution of adult salmon as low flows interfere with returns of larger-bodied fish. We examined these relationships of abundance and body size within Catamaran Brook, a third-order tributary to the Miramichi River system of New Brunswick, Canada, to investigate the causes of a declining trend in annual returns of Atlantic salmon (Salmo salar) to this stream. Regression models of adult abundance, proportion of the run as grilse, and body size of returning adults as functions of maximum daily stream discharge during the period of upstream spawner migration were constructed. Adult abundance shows a logarithmic relationship with stream discharge and provides good predictive ability, while appearing to not be significantly related to adult abundance in the larger Miramichi system. The proportion as grilse in the run and female body size are also logarithmically related to stream discharge, with low flow years being very influential in the regressions. These relationships of Atlantic salmon population abundance and body size characteristics have implications with respect to stock integrity and production of the following generation.

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Effects of Weir Construction on Phytoplankton Assemblages and Water Quality in a Large River System

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph15112348 ◽

2018 ◽

Vol 15 (11) ◽

pp. 2348 ◽

Cited By ~ 9

Author(s):

Hae-Jin Lee ◽

Hae-Kyung Park ◽

Se-Uk Cheon

Keyword(s):

Water Quality ◽

Chlorophyll A ◽

River System ◽

Large River ◽

Anthropogenic Factors ◽

Centric Diatom ◽

Nakdong River ◽

Biological Variables ◽

Physical Chemical ◽

The Nakdong River

Flow regulation is one of the most common anthropogenic factors affecting rivers worldwide. In Korea, 16 weirs were constructed along four major rivers from 2009 to 2012. This study aimed to elucidate initial changes in physical, chemical, and biological variables after the construction of consecutive weirs on the Nakdong River, a major large river system. Water quality variables and phytoplankton cell densities were investigated at eight representative sites and compared with the data recorded before the weir construction. There were spatial and temporal changes in the hydraulic retention time (HRT), total phosphorus (TP), and chlorophyll a concentrations among the eight weir sections. HRT increased after the weir construction, while TP and chlorophyll a tended to decrease from the middle to lower section of the Nakdong River. Furthermore, differences were observed in the phytoplankton community composition between 2006–2007 and 2013. There was a marginal decrease in the duration of centric diatom (Stephanodiscus hantzschii) blooms after weir construction. However, Microcystis aeruginosa proliferated more extensively during summer and autumn than it did before the weir construction. Our results suggest that changes in hydrological factors, in response to consecutive weir construction, may contribute to greater physical, chemical, and ecological variability.

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