The use of hatchery technology for the conservation of Pacific and Atlantic salmon

Maynard, Desmond J.; Trial, Joan G.

doi:10.1007/s11160-013-9341-7

Cited by 25 publications

(27 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is possible that some of the fish that we classified as wild origin were, in fact, stocked as fry. Managers used fry stocking as a primary recovery tool in these rivers especially after 1990 (Hogan and Friedland 2010;Maynard and Trial 2014). Hatchery-origin stocked fry would be indistinguishable from wild-spawned fish based on scale readings, so it is unclear what percentage of fish in our sample were entirely wild.…”

Section: Discussionmentioning

confidence: 99%

Retrospective Analysis of Seasonal Ocean Growth Rates of Two Sea Winter Atlantic Salmon in Eastern Maine Using Historic Scales

Izzo

Zydlewski

2017

Mar Coast Fish

View full text Add to dashboard Cite

Substantial declines of anadromous Atlantic Salmon Salmo salar have occurred throughout its range, with many populations at the southern extent of the distribution currently extirpated or endangered. While both one sea winter (1SW) and two sea winter (2SW) spawner numbers for the North American stocks have declined since the 1950s, the decline has been most severe in 2SW spawners. The first months at sea are considered a period of high mortality. However, early ocean mortality alone cannot explain the more pronounced decline of 2SW spawners, suggesting that the second year at sea may be more critical than previously thought. Atlantic Salmon scales collected by anglers and the state agency from 1946 to 2013 from five rivers in eastern Maine were used to estimate smolt age and ocean age of returning adults. Additionally, seasonal growth rates of maiden 2SW spawners were estimated using intercirculi measurements and linear back‐calculation methods. Generalized linear mixed models (Gaussian family, log link function) were used to investigate the influence of average sea surface temperature, accumulated thermal units, the Atlantic Multidecadal Oscillation (AMO) and North Atlantic Oscillation indices, smolt age, smolt length, postsmolt growth, and river of origin on growth rate during the oceanic migration of North American Atlantic Salmon. Results suggest that different factors influence salmon growth throughout their oceanic migration, and previous growth can be a strong predictor of future size. Growth was negatively impacted by the phase of the AMO, which has been linked to salmon abundance trends, in early spring following the postsmolt period. This is likely when the 1SW and 2SW stock components separate, and our results suggest that this period may be of interest in future work examining the disproportionate decline in 2SW spawners.

show abstract

Section: Discussionmentioning

confidence: 99%

Retrospective Analysis of Seasonal Ocean Growth Rates of Two Sea Winter Atlantic Salmon in Eastern Maine Using Historic Scales

Izzo

Zydlewski

2017

Mar Coast Fish

View full text Add to dashboard Cite

show abstract

“…Hatchery supplementation efforts have prevented remnant populations of Atlantic Salmon from going extinct, but their recovery has not been realized, and many populations remain dependent on hatchery intervention (NRC 2004;Fay et al 2006). Atlantic Salmon were first reared for supplementation of wild stocks in Maine during the late 1800s (Maynard and Trial 2014). Since that time, hatchery practices have evolved, with the development of a river-specific broodstock program in the early 1990s .…”

mentioning

confidence: 99%

Assessment of Early Migration Dynamics of River‐Specific Hatchery Atlantic Salmon Smolts

2017

View full text Add to dashboard Cite

Many Atlantic Salmon Salmo salar populations within the southern extent of the species’ range are at critically low abundances, while others have been extirpated. The focus of many ongoing recovery efforts is on maximizing the number of smolts that reach the ocean, where marine survival is low, primarily through hatchery supplementation and improvement of in‐river hydropower system management. However, estuaries also are known to be sites of high mortality, although in many cases the correlates of this mortality are poorly characterized. We acoustically tagged hatchery smolts (n = 666) during 2001–2005 to evaluate migration performance through freshwater, estuarine, and bay reaches of the small but tidally dynamic Dennys River, Maine, USA, to investigate potential drivers contributing to low returns within the system. Migration behaviors (e.g., migration timing and tidal use) were typical for Atlantic Salmon smolts, but reversals during migration were observed upon entry into the estuary environment more frequently in this system than in regional rivers. We used Cormack–Jolly–Seber mark–recapture models to estimate apparent survival within the study environment during this period. We found two distinct periods of survival, with much lower survival in 2003–2005 than in 2001 and 2002 (more than a 40% decrease). Among the variables considered, temperature and migratory behavior had the largest effects on survival. We found that survival increased by about 28% across the range of temperatures observed during these years; additionally, survival increased by about 15% for fish that reversed direction during migration compared to fish that did not. These results indicate that extreme environmental changes during the transition through this coastal system constitute a significant obstacle to Atlantic Salmon restoration stocking efforts.

show abstract

“…This suite of papers synthesizes how modern conservation hatchery programs are providing demographic and genetic support to enhance recovery of endangered wild populations while attempting to minimize negative impacts of hatchery culture on fitness. First, Maynard and Trial (2014) provide a comprehensive overview of societal paradigm shifts where goals for Pacific and Atlantic salmon hatcheries over the past 140 years evolved from using hatcheries to improve on nature to a focus on natural rearing within hatcheries. The next two papers focus on the essential role hatcheries are playing in preventing extinction of critically endangered salmon populations.…”

Section: Conservation Hatcheriesmentioning

confidence: 99%

Collaboration between Atlantic and Pacific salmon biologists to enhance recovery of endangered salmon in North America

Ardren

Busack

Kocik

2014

Rev Fish Biol Fisheries

View full text Add to dashboard Cite

The use of hatchery technology for the conservation of Pacific and Atlantic salmon

Cited by 25 publications

References 24 publications

Retrospective Analysis of Seasonal Ocean Growth Rates of Two Sea Winter Atlantic Salmon in Eastern Maine Using Historic Scales

Retrospective Analysis of Seasonal Ocean Growth Rates of Two Sea Winter Atlantic Salmon in Eastern Maine Using Historic Scales

Assessment of Early Migration Dynamics of River‐Specific Hatchery Atlantic Salmon Smolts

Collaboration between Atlantic and Pacific salmon biologists to enhance recovery of endangered salmon in North America

Contact Info

Product

Resources

About