Wintertime growth in Atlantic salmon under changing climate: the importance of ice cover for individual growth dynamics

Understanding the dynamic nature of individual growth in stream-dwelling salmonids may help forecast consequences of climate change on northern fish populations. Here, we performed an experimental capture-mark-recapture study in Atlantic salmon to quantify factors influencing wintertime growth variation among juveniles under different scenarios for ice cover reduction. We applied multiple imputation to simulate missing size observations for unrecaptured fish, and to account for individual-level variation in growth rates. The salmon parr exhibited substantial body length shrinkage in early winter, suppressed growth through mid-winter, and increasing growth rates in late winter and particularly in spring. Unexpectedly, the presence of ice cover had no direct effects on wintertime growth. Instead, our results implied increasing energetic costs with reducing ice cover: individuals exposed to absent or shortened ice-covered period gained mass at a lowered rate in spring whereas the present, long ice-covered period was followed by rapid growth. This study emphasizes natural resilience of Atlantic salmon to wintertime environmental variation which may help the species to cope with the reductions in ice cover duration due to climate change.

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Differentiation in juvenile growth and bimodality patterns between northern and southern populations of Atlantic salmon (Salmo salar L.)

Canadian Journal of Zoology ◽

10.1139/z94-213 ◽

1994 ◽

Vol 72 (9) ◽

pp. 1603-1610 ◽

Cited By ~ 70

Author(s):

Alfredo G. Nicieza ◽

Felipe G. Reyes-Gavilán ◽

Florentino Braña

Keyword(s):

Atlantic Salmon ◽

Salmo Salar ◽

Growth Rates ◽

Individual Growth ◽

Late Winter ◽

Southern Population ◽

Northern Spain ◽

Atlantic Salmon Salmo Salar ◽

Juvenile Atlantic Salmon ◽

Modal Group

Juvenile Atlantic salmon, Salmo salar, from two contrasting populations that had been reared under identical conditions differed in freshwater growth rates and the development of bimodality in length–frequency distributions. Segregation by size started at least a month earlier in the northern (River Shin, northern Scotland) than in the southern population (River Narcea, northern Spain). Northern fish initially grew faster and entered the upper modal group at a larger size (about 100 mm) than did southern fish (about 90 mm). However, the percentage of fish in the upper modal group was greater for the southern population and they grew fastest over winter and during the spring leading up to smolting, and were larger at the smolt stage. By late winter, the individual growth rates of upper modal fish were inversely correlated with their body length in December. These results suggest the existence of genetic differences between populations in the expression of growth bimodality in juvenile Atlantic salmon. This may indicate that size and growth rate thresholds determining the developmental pathway associated with age at smolt metamorphosis may vary between populations as a function of both smolt size and expected growth opportunity during winter and spring.

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Dynamics of individual growth in a recovering population of lake trout (Salvelinus namaycush)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f00-232 ◽

2001 ◽

Vol 58 (2) ◽

pp. 262-272 ◽

Cited By ~ 9

Author(s):

Mary C Fabrizio ◽

Robert M Dorazio ◽

Stephen T Schram

Keyword(s):

Growth Rates ◽

Lake Trout ◽

Growth Dynamics ◽

Salvelinus Namaycush ◽

Wild Fish ◽

Individual Growth ◽

Wisconsin Department ◽

Growth Increments ◽

Before And After ◽

The Mean

In 1976, the Wisconsin Department of Natural Resources established a refuge for a nearly depleted population of lake trout (Salvelinus namaycush) at Gull Island Shoal, Lake Superior. The refuge was intended to reduce fishing mortality by protecting adult lake trout. We examined the growth dynamics of these lake trout during the period of recovery by comparing estimates of individual growth before and after the refuge was established. Our estimates are based on an annual mark-recapture survey conducted at the spawning area since 1969. We developed a model that allowed mean growth rates to differ among individuals of different sizes and that accommodated variation in growth rates of individuals of the same size. Likelihood ratio tests were used to determine if the mean growth increments of lake trout changed after the refuge was established. Our results suggest that growth of mature lake trout (particularly wild fish) decreased significantly in the postrefuge period. This decreased growth may have been associated with a reduction in food availability. We also observed reductions in growth as wild fish grew older and larger, which suggests that the growth of these fish may be adequately approximated by a von Bertalanffy growth model if it becomes possible to obtain accurate ages.

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Effects of Extended Daylength on Autumn Growth Dynamics of Juvenile Atlantic Salmon, Salmo salar

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f90-086 ◽

1990 ◽

Vol 47 (4) ◽

pp. 755-759 ◽

Cited By ~ 8

Author(s):

Mark W. Stewart ◽

Richard L. Saunders ◽

A. J. Wiggs

Keyword(s):

Atlantic Salmon ◽

Salmo Salar ◽

Growth Rates ◽

Size Range ◽

Fork Length ◽

Growth Dynamics ◽

Atlantic Salmon Salmo Salar ◽

Juvenile Atlantic Salmon ◽

Light:Dark Cycle ◽

Modal Group

The growth and growth dynamics of juvenile Atlantic salmon (Salmo salar) exposed from mid-August to mid-December to either a normal light:dark cycle (LDN) or a constant 16-h light:8-h dark (LD 16:8) photoperiod were compared. Exposure to the LD 16:8 resulted in 38.1% of the fish entering the upper modal group (UMG) of the length–frequency distribution, while only 15.4% entered the UMG under LDN. The length at which fish entered the UMG (critical fork length) did not differ between photoperiods. Fish in the small (5.8–6.7 cm) and middle (6.8–7.7 cm) size-ranges under LD 16:8 had greater growth rates than fish in the same size-ranges under LDN. Fish in the large (8.3–9.2 cm) size-range showed no significant variation in growth rates between photoperiods. At the end of the experiment, mean thyroxine (T4) levels were significantly (P < 0.05) lower in fish from the LD 16:8 photoperiod (1.69 ng/mL) in comparison with LDN fish (3.96 ng/mL). Triiodothyronine (T3) levels and the T3/T4 ratio were elevated under LD 16:8.

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Patterns of Growth and Smolting of Atlantic Salmon (Salmo salar) Parr in a Southwestern Newfoundland River

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f85-071 ◽

1985 ◽

Vol 42 (3) ◽

pp. 539-543 ◽

Cited By ~ 5

Author(s):

Geoffrey T. Evans ◽

Jake C. Rice ◽

E. Michael P. Chadwick

Keyword(s):

Growth Rate ◽

Simple Model ◽

Atlantic Salmon ◽

Salmo Salar ◽

Growth Rates ◽

Individual Growth ◽

Atlantic Salmon Salmo Salar ◽

Random Samples ◽

Non Gaussian

A simple model of growth and smolting of Atlantic salmon (Salmo salar) parr, which can account for distributions of ages and lengths of random samples of sea-run smolts in Western Arm Brook, in northern Newfoundland, cannot account for distributions in Little Codroy River, in southwestern Newfoundland. Possible reasons for discrepancies include mortality dependent on growth rates, non-Gaussian growth rate distributions, and variability in individual growth rates. Smolt data do not allow us to reject any of these possibilities. Precocious maturation of male parr does not account for the discrepancies.

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Quantifying thermal effects on contemporary growth variability to predict responses to climate change in northern rock sole (Lepidopsetta polyxystra)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f09-171 ◽

2010 ◽

Vol 67 (1) ◽

pp. 97-107 ◽

Cited By ~ 16

Author(s):

Thomas P. Hurst ◽

Alisa A. Abookire ◽

Brian Knoth

Keyword(s):

Climate Change ◽

Growth Rates ◽

Environmental Control ◽

Thermal Sensitivity ◽

Larval Growth ◽

Growth Dynamics ◽

Growth Strategy ◽

Nursery Ground ◽

Growth Variability ◽

Coastal Marine

Understanding the causes of contemporary variation in growth rates can offer insights into the likely consequences of climate change for growth and recruitment of coastal marine fishes. We examined the growth dynamics of age-0 northern rock sole ( Lepidopsetta polyxystra ) over four years in three nurseries at Kodiak Island, Alaska, USA. Following the settlement period, fish were sampled monthly (July–October) with a 3 m beam trawl at fixed-position transects. Postsettlement sizes were positively related to temperatures during the spawning and larval periods, suggesting environmental control of spawning or settlement timing. Summer growth on the nursery grounds varied significantly among sites and years (mean size 32.8–63.1 mm in mid-September), with the Holiday Beach site consistently supporting the fastest growth rates. Contrary to expectations of density dependence and thermal regulation, nursery ground growth rates were not significantly correlated with fish density or water temperatures. The minor contribution of thermal variation to growth rates appears related to the conservative growth strategy and low thermal sensitivity of northern rock sole. These results suggest that climate changes influencing spawning time and larval growth may have larger impacts on first-year growth and recruitment of this species than temperature effects on the growth of nursery-resident juveniles.

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Impacts of Paris Agreement on Russian economy

Voprosy Ekonomiki ◽

10.32609/0042-8736-2018-4-76-94 ◽

2018 ◽

pp. 76-94 ◽

Cited By ~ 1

Author(s):

I. A. Makarov ◽

C. Henry ◽

V. P. Sergey

Keyword(s):

Climate Change ◽

Economic Policy ◽

Growth Rates ◽

Paris Agreement ◽

Gdp Growth ◽

Russian Economy ◽

Climate Policies

The paper applies multiregional CGE Economic Policy Projection and Analysis (EPPA) model to analyze major risks the Paris Agreement on climate change adopted in 2015 brings to Russia. The authors come to the conclusion that if parties of the Agreement meet their targets that were set for 2030 it may lead to the decrease of average annual GDP growth rates by 0.2-0.3 p. p. Stricter climate policies beyond this year would bring GDP growth rates reduction in2035-2050 by additional 0.5 p. p. If Russia doesn’t ratify Paris Agreement, these losses may increase. In order to mitigate these risks, diversification of Russian economy is required.

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GROWTH OF PIKE-PERCH SANDER LUCIOPERCA (L., 1758) (PERCIDAE) IN RESERVOIRS OF K. SATPAYEV’S CHANNEL

VESTNIK OF ASTRAKHAN STATE TECHNICAL UNIVERSITY SERIES FISHING INDUSTRY ◽

10.24143/2073-5529-2018-1-59-68 ◽

2018 ◽

pp. 59-68

Author(s):

Saule Zhangirovna Asylbekova ◽

Kuanysh Baibulatovich Isbekov ◽

Vladimir Nickolaevich Krainyuk

Keyword(s):

Growth Rates ◽

Growth Dynamics ◽

High Growth ◽

Water Bodies ◽

Volga River ◽

Trophic Resources ◽

Pike Perch ◽

The Amur River ◽

Back Calculation ◽

Abiotic And Biotic Factors

Pike-perch is an invader for the water basins of Central Kazakhstan. These species have stable self-reproductive populations in the regional waters. Back calculation method was used to investigate pike-perch growth rates in reservoirs of K. Satpayev’s channel. For comparison, the data from the other water bodies (Vyacheslavsky and Sherubay-Nurinsky water reservoirs) were used, as well as literature data. Pike-perch species from the investigated waters don’t show high growth rates. The populations from the reservoirs of K. Satpayev’s channel have quite similar growth rates with populations from the Amur river, from a number of reservoirs in the Volga river basin and from the reservoir in Spain. Sexual differences in growth have not been observed. Evaluating possible influence of various abiotic and biotic factors on the growth rate of pike-perch in the reservoirs of K. Satpayev’s channel was carried out. It has been stated that the availability of trophic resources cannot play a key role in growth dynamics because of their high abundance. Morphology of water bodies also does not play a role, as well as chromaticity, turbidity and other optical water indicators. It can be supposed that the main factor influencing growth of pike perch is the habitat’s temperature. This factor hardly ever approaches optimal values for the species in reservoirs of K. Satpaev’s channel. The possible influence of fishing selectivity on pike-perch growth rates was also evaluated. Currently, there has been imposed a moratorium on pike-perch catch. However, pike-perch is found in by-catches and in catches of amateur fishermen. It should be said that such seizures have an insignificant role in the dynamics of growth rates.

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Geostatistically modeling stem size and increment in an old-growth forest

Canadian Journal of Forest Research ◽

10.1139/x94-176 ◽

1994 ◽

Vol 24 (7) ◽

pp. 1354-1368 ◽

Cited By ~ 95

Author(s):

Franco Biondi ◽

Donald E. Myers ◽

Charles C. Avery

Keyword(s):

Spatial Patterns ◽

Growth Rates ◽

Spatial Dependence ◽

Basal Area ◽

Tree Density ◽

Individual Growth ◽

Old Growth ◽

Model Estimate ◽

Stem Size ◽

Old Growth Forest

Geostatistics provides tools to model, estimate, map, and eventually predict spatial patterns of tree size and growth. Variogram models and kriged maps were used to study spatial dependence of stem diameter (DBH), basal area (BA), and 10-year periodic basal area increment (BAI) in an old-growth forest stand. Temporal variation of spatial patterns was evaluated by fitting spatial stochastic models at 10-year intervals, from 1920 to 1990. The study area was a naturally seeded stand of southwestern ponderosa pine (Pinusponderosa Dougl. ex Laws. var. scopulorum) where total BA and tree density have steadily increased over the last decades. Our objective was to determine if increased stand density simply reduced individual growth rates or if it also altered spatial interactions among trees. Despite increased crowding, stem size maintained the same type of spatial dependence from 1920 to 1990. An isotropic Gaussian variogram was the model of choice to represent spatial dependence at all times. Stem size was spatially autocorrelated over distances no greater than 30 m, a measure of average patch diameter in this forest ecosystem. Because patch diameter remained constant through time, tree density increased by increasing the number of pine groups, not their horizontal dimension. Spatial dependence of stem size (DBH and BA) was always much greater and decreased less through time than that of stem increment (BAI). Spatial dependence of BAI was close to zero in the most recent decade, indicating that growth rates in 1980–1990 varied regardless of mutual tree position. Increased tree crowding corresponded not only to lower average and variance of individual growth rates, but also to reduced spatial dependence of BAI. Because growth variation was less affected by intertree distance with greater local crowding, prediction of individual growth rates benefits from information on horizontal stand structure only if tree density does not exceed threshold values. Simulation models and area estimates of tree performance in old-growth forests may be improved by including geostatistical components to summarize ecological spatial dependence.

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