scholarly journals Environmental effects on survival rates: robust regression, recovery planning and endangered Atlantic salmon

2015 ◽  
Vol 5 (16) ◽  
pp. 3450-3461 ◽  
Author(s):  
Heather D. Bowlby ◽  
A. Jamie F. Gibson
Keyword(s):  
Atlantic Salmon ◽  
Environmental Effects ◽  
Robust Regression ◽  
Survival Rates ◽  
Recovery Planning

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.

Estimated Escapement of Atlantic Salmon (Salmo salar) for Maximum Smolt Production in Rivers of Different Productivity

1979 ◽  
Vol 36 (2) ◽  
pp. 132-140 ◽  
Author(s):  
Philip E. K. Symons
Keyword(s):  
Atlantic Salmon ◽  
Water Temperature ◽  
Salmo Salar ◽  
Fishery Management ◽  
Survival Rates ◽  
Atlantic Salmon Salmo Salar ◽  
Egg Deposition ◽  
Average Maximum ◽  
Game Fish ◽  
Space Requirements

Smolt production at different egg deposition densities is estimated from data on survival rates and space requirements of juvenile Atlantic salmon (Salmo salar) reported in the literature. Average maximum production of smolts is estimated to be approximately 5/100 m2 for 2+ smolts, 2/100 m2 for 3+ smolts, and 1/100 m2 for 4+ smolts. Minimum egg depositions recommended for production of these numbers of smolts are 220/100 m2, 165–220/100 m2, and 80/100 m2 for each age of smolts, respectively. The escapement of adults required to produce these depositions must be estimated from observed average weights of returning females and a reported fecundity of Atlantic salmon between 1650 and 1760 eggs/kg of female. With the exception of Ungava rivers, average smolt age in any particular river can be estimated from the number of days per year on which water temperature reaches or exceeds 7 °C. Key words: fishery resources, fishery management, production (biological), escapement, survival, game fish, freshwater fish, rivers

scholarly journals Atlantic salmon (Salmo salar) smolt and early post-smolt migration and survival inferred from multi-year and multi-stock acoustic telemetry studies in the Gulf of St. Lawrence, northwest Atlantic

2018 ◽  
Vol 76 (4) ◽  
pp. 1107-1121 ◽  
Author(s):  
Gérald Chaput ◽  
Jonathan Carr ◽  
Jason Daniels ◽  
Steve Tinker ◽  
Ian Jonsen ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Survival Rates ◽  
Fork Length ◽  
Probability Of Survival ◽  
Size Dependent ◽  
Atlantic Salmon Salmo Salar ◽  
Key Points ◽  
Migration Dynamics

Abstract The migration dynamics and inter-annual variation in early at-sea survival of Atlantic salmon (Salmo salar) smolts over 14 years of study are reported for four river populations located in the Gulf of St. Lawrence (Canada). Acoustically tagged smolts were monitored at three points along their migration from freshwater to the Labrador Sea, a migration extending more than 800 km at sea and a period of 2 months. A hierarchical state-space version of the Cormack–Jolly–Seber model was used to estimate apparent survival rates from incomplete acoustic detections at key points. There was a positive size-dependent probability of survival through the freshwater and estuary areas; the odds of survival of a 16 cm smolt were 1.5–1.7 times higher than for a 13.5 cm smolt, length at tagging. Length adjusted (centred to the mean fork length of smolts during the study of 14.6 cm) survivals through the estuary and nearshore waters were estimated to range between 67 and 90% for the two river populations migrating through Chaleur Bay in contrast to lower survival estimates of 28–82% for the two populations from the neighbouring Miramichi Bay. Across the 14 years of study, survival estimates varied without trend for the populations of Chaleur Bay, but declined for the populations migrating through Miramichi Bay. Survival through the Gulf of St. Lawrence was variable but generally high among years and rivers, ranging from 96% day−1 to 99% day−1. Long term, replicated studies at multiple sites using acoustically tagged smolts can provide empirical data to examine hypotheses of the location and timing of factors contributing to smolt and post-smolt mortality of salmon at sea.

Effects of predation on telemetry-based survival estimates: insights from a study on endangered Atlantic salmon smolts

2015 ◽  
Vol 72 (5) ◽  
pp. 728-741 ◽  
Author(s):  
A. Jamie F. Gibson ◽  
Edmund A. Halfyard ◽  
Rod G. Bradford ◽  
Michael J.W. Stokesbury ◽  
Anna M. Redden
Keyword(s):  
Atlantic Salmon ◽  
Striped Bass ◽  
Survival Rates ◽  
Morone Saxatilis ◽  
Population Level ◽  
Fish Predation ◽  
Bay Of Fundy ◽  
Migration Patterns ◽  
Predation Effects

Telemetry is increasingly being used to estimate population-level survival rates. However, these estimates may be affected by the detectability of telemetry tags and are reliant on the assumption that telemetry data represent the movements of the tagged fish. Predation on tagged fish has the potential to bias survival estimates, and unlike the issue of detectability, methods to correct for the resulting bias (termed “predation bias”) are not yet developed. In an acoustic telemetry study on inner Bay of Fundy Atlantic salmon (Salmo salar) smolts during 2008 and 2011, unusual tag detection patterns were indicative that some data may have been representative of the movements of predators rather than smolts. To incorporate predation effects into the resulting survival estimates, a suite of 11 summary migration metrics were compared between Atlantic salmon smolts and striped bass (Morone saxatilis). Cluster analyses revealed that 2.4% to 13.6% of tags implanted in smolts exhibited migration patterns more similar to striped bass than to other smolts, which was interpreted here as evidence of predation. Reassigning the fate of these tags as “depredated–died” reduced estimated survival from 43.5% to 41.1% in 2008 and from 32.6% to 19.0% in 2011 relative to a traditional mark–recapture model, illustrating the effect of predation bias in this case study.

Impact of an Acid Spill on the Resident Fauna of the York River and its Recovery

1989 ◽  
Vol 24 (4) ◽  
pp. 569-582
Author(s):  
R. Prairie ◽  
K. Schiefer ◽  
L.J. Moulins ◽  
V. Chapados
Keyword(s):  
Water Quality ◽  
Atlantic Salmon ◽  
Benthic Communities ◽  
Survival Rates ◽  
Juvenile Salmon ◽  
York River ◽  
Aquatic Fauna ◽  
Biological Studies ◽  
Metal Levels

Abstract As a result of a sulphuric acid spill in June 1982 at the Mines Gaspé operation in Murdochville, Québec, water quality of effluents being discharged into the headwaters of the York River was temporarily impaired. It rapidly became apparent that the aquatic fauna of this important Atlantic salmon river had been affected in some areas. This paper provides an overview of the results obtained in biological studies (Atlantic salmon population and benthic communities) carried out by Beak Consultants Ltd. and Noranda Technology Centre, annually, from 1982 to 1985. The biological and water chemistry surveys carried out during this four-year period indicated a short duration event of high dissolved metal levels, primarily copper, shortly after the spill, followed by a rapid improvement in water quality. Both the aquatic macroinvertebrate benthos and fish life in the river were negatively impacted. The nature and degree of this impact as well as the subsequent recolonization of aquatic habitats by both groups were observed and documented. The most affected aquatic groups in 1982 were the youngest salmon age classes (0+ and 1+) along with the intermediate and sensitive benthic communities. This impact was mainly observed in the upper and middle river section. Maintenance of suitable water quality during the following years has permitted excellent survival rates for juvenile salmon and recolonization of benthic habitats by sensitive species. This has contributed to the gradual re-establishment of a natural aquatic fauna in the York River. More recent surveys carried out since 1985 confirm that the quality of the York River ecosystem has been maintained and suggest that the survival rates observed for juvenile salmon are higher than the theoretical values usually used in salmon production models.

scholarly journals Interannual changes in recruitment of the Atlantic salmon (Salmo salar) population in the River Oir (Lower Normandy, France): relationships with spawners and in-stream habitat

2005 ◽  
Vol 62 (4) ◽  
pp. 695-707 ◽  
Author(s):  
Jean-Luc Baglinière ◽  
Frédéric Marchand ◽  
Vincent Vauclin
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Survival Rates ◽  
Stream Habitat ◽  
Juvenile Salmon ◽  
Strongly Correlated ◽  
Data Set ◽  
Atlantic Salmon Salmo Salar ◽  
Salmon Population ◽  
The Mean

Abstract Since 1985, the dynamics of the Atlantic salmon (Salmo salar) population in the River Oir, a spawning tributary of the River Sélune (Lower Normandy, France), have been studied from a data set of parr density and the number and the age structure of migrating fish (smolts and adults). Parr densities (1.5–17.4 per 100 m2) and smolt production (0.25–9.2 per 100 m2) varied considerably from year to year. Migrating juveniles were mainly 1 year old. Abundance of parr and smolts was strongly correlated with 0+ densities. Egg-to-smolt survival rates were highly variable year on year (0.044–1.07%). During the juvenile freshwater phase, mortality was highest between the egg and the 0+ stage (97.5–99.9%). The fluctuations in abundance of juvenile salmon appear to be linked to the number and distribution of spawners within the stream during spawning, and also to the amount of silt deposition on the spawning beds. As a result, mortality was highest during the under-gravel phase, and the mean survival rate from egg to smolt was much lower than in rivers less impacted by human activities. Therefore, during the study period, the low production of smolts during some years might lead to a low renewal rate of the salmon population.

Immersion during egg swelling results in rapid uptake of stable isotope markers in salmonid otoliths

2015 ◽  
Vol 72 (5) ◽  
pp. 722-727 ◽  
Author(s):  
Fletcher Warren-Myers ◽  
Tim Dempster ◽  
Per Gunnar Fjelldal ◽  
Tom Hansen ◽  
Stephen E. Swearer
Keyword(s):  
Stable Isotopes ◽  
Cost Effectiveness ◽  
Stable Isotope ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Low Cost ◽  
Survival Rates ◽  
Hatchery Fish ◽  
Salmon Eggs ◽  
Identification Techniques

Determining the value of restocking wild fisheries with hatchery-reared fish requires the ability to identify and quantify the survival of hatchery fish after release. However, to obtain accurate estimates of survival rates, multiple fish identification techniques are often used, making the monitoring of restocking inefficient and costly. Here we test a new immersion marking method to determine its efficiency and cost effectiveness for marking millions of hatchery-reared Atlantic salmon (Salmo salar). Salmon eggs were marked during the egg swelling stage by immersing eggs in a solution containing seven enriched stable isotopes (134Ba, 135Ba, 136Ba, 137Ba, 86Sr, 87Sr, and 26Mg) for 2 h immediately after fertilisation. One hundred percent successful marks were detected in the otoliths of resulting larvae at a concentration of 1000 μg·L−1 for 136Ba and 100 μg·L−1 for 135Ba and 137Ba, with no detrimental effects on survival or health of egg and yolk sac larvae. We estimate that seven unique mark combinations can be made at a cost of $0.0001 to $0.0017 (US) per egg and conclude that marking via egg immersion is suitable for low cost, accurate marking of hatchery-reared salmonids destined for restocking purposes.

Performance of crossbred progeny of Trangie Fertility Merino and Booroola Merino rams and Poll Dorset ewes. 1. Lamb birth weight, survival and growth

1995 ◽  
Vol 35 (8) ◽  
pp. 1069 ◽  
Author(s):  
DG Hall ◽  
NM Fogarty ◽  
AR Gilmour
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
Environmental Effects ◽  
Growth Rates ◽  
Survival Rates ◽  
Age And Growth ◽  
Weaning Weight ◽  
Survival And Growth ◽  
The Common ◽  
Lamb Survival

Merino rams of the Trangie Fertility and Booroola strains were joined to Poll Dorset ewes in single sire mating groups over 3 years. Forty sires produced a total of 1250 lambs in 885 litters from 451 ewes. Lamb birth weight averaged 4.1 kg, 80.8% of lambs survived to 3 days of age and growth rates to weaning (mean 93 days) averaged 289 g/day. Lambs with Trangie Fertility sires grew 15 g/day faster and were 1.3 kg heavier at weaning than those lambs with Booroola sires (P<0.001). There were no effects of sire strain on birth weight or lamb survival. Birth weight increased with dam liveweight in mid-pregnancy (P<0.001), and weaning weight and growth rate increased with dam liveweight at joining (P<0.001). Survival of lambs was predominantly a function of birth weight. Lambs weighing 4 kg at birth from primiparous dams had survival rates of 76% compared with 88% for lambs from multiparous dams (P<0.01). No lamb under 2.0 or over 6.3 kg survived, and 48% of deaths occurred within 1 day of birth. Dystocia, particularly of heavy, single-born lambs, caused 53% of observed lamb deaths. For the traits birth weight, lamb survival, weaning weight and growth rate, the direct heritabilities were 0.24 � 0.10, 0.05 � 0.05, 0.19 � 0.10 and 0.12 � 0.08 respectively; the corresponding maternal heritabilities were 0.08 � 0.05, 0.05 � 0.04, 0.05 � 0.05 and 0.07 � 0.05 respectively; and the common environmental effects among litter mates (c2) were 0.57 � 0.08, 0.47 � 0.08, 0.15 � 0.08 and 0.13 � 0.08 respectively.

Sign in / Sign up

Export Citation Format

Share Document