scholarly journals The largest Baltic population of sea trout (Salmo trutta L.): its decline, restoration attempts, and current status

2018 ◽  
Vol 26 (2) ◽  
pp. 81-100 ◽  
Author(s):  
Piotr Dębowski
Keyword(s):  
River Basin ◽  
Salmo Trutta ◽  
Current Status ◽  
Late Nineteenth Century ◽  
Sea Trout ◽  
Vistula River ◽  
Current State ◽  
Baltic Population ◽  
Mature Fish ◽  
The Baltic

Abstract The sea trout, Salmo trutta L. population in the Vistula River was the largest in the Baltic Sea. Its primary spawning grounds were located in the Carpathian tributaries in the upper river basin. The fish ascended to spawn in two runs: in winter when the fish were immature and spent nearly a whole year in the river, and in summer when mature fish ascended the river and spawned within a few months. This work presents the fisheries and stocking history and scientific studies of this population from the late nineteenth century. The consequences of the most important changes in the sea trout habitat are tracked from construction in the upper river basin in the 1940s and the damming of the river in its middle reaches in Włocławek in 1969. Despite intense stocking that has been conducted for over one hundred years, catches have declined from over 100 tons to nearly zero in recent years. The current state of the population and the possibilities of restoring it are discussed in light of genetic studies.

scholarly journals The genetic approach for assessing sea trout stock enhancement efficiency – An example from the Vistula River

2017 ◽  
Vol 25 (2) ◽  
pp. 65-75
Author(s):  
Anna Wąs-Barcz ◽  
Rafał Bernaś ◽  
Roman Wenne
Keyword(s):  
Salmo Trutta ◽  
Stock Enhancement ◽  
Anthropogenic Pressure ◽  
Sea Trout ◽  
Baltic Countries ◽  
Vistula River ◽  
Lack Of Information ◽  
The 1960S ◽  
The Baltic ◽  
Baltic Sea Basin

AbstractMany countries in the Baltic Sea basin have initiated enhancement programs for Baltic migratory sea trout,Salmo truttaL., to compensate for losses stemming from anthropogenic pressure that has resulted in the declining population abundance of this species. Regular stock enhancement has been conducted in Poland since the 1960s. Currently, over one million sea trout smolts are released into Polish rivers annually. In most Baltic countries, including Poland, stock enhancement depends on hatcheries producing material using spawners caught in native rivers. However, increasing difficulty obtaining spawners in recent years in Poland has meant that stock enhancement performed in the Vistula has been done largely with material obtained from broodstocks. Simultaneously, there is a lack of information regarding the proportion of wild and cultured sea trout in this river basin. This paper is a review of methods applied to identify individuals from natural and artificial sea trout spawning in rivers, and it proposes using genetic techniques as an alternative to traditional marking methods. A set of 13 microsatellite loci are proposed that are characterized by high selectivity. Using negative controls while simulating the assignment of parental pairs revealed that the number of loci in the set was highly significant and should not be reduced. This method could be useful in the proposed assessment of the proportions of wild and cultured fish in Polish rivers.

scholarly journals Climate Change Impact on Salmon (Salmo salar) and Sea Trout (Salmo trutta) in the Salaca River, Latvia

2020 ◽  
pp. 17-26
Author(s):  
Janis Birzaks
Keyword(s):  
Atlantic Salmon ◽  
Water Temperature ◽  
Salmo Salar ◽  
Salmo Trutta ◽  
Age Groups ◽  
Average Water Temperature ◽  
Sea Trout ◽  
The One ◽  
The Baltic

Hydrometeorological conditions are important determinants of the distribution, abundance and growth of Atlantic salmon (Salmo salar) and sea trout (Salmo trutta) parr and smolt in rivers. Long-term monitoring of the temperate zone Salaca River was conducted to investigate long-term changes in water temperature and streamflow and their effects on juvenile Atlantic salmon and sea trout. The average water temperature in the Salaca River was found to increase over time, particularly in autumn, winter and spring. River discharge increased in winter and summer, which was caused by increased precipitation. Goals of our study were: 1) to examine trends in water temperature and discharge in the river, 2) to explore relations between hydrometeorological trends, on the one hand, and abundance, size at age of salmon and sea trout parr and smolt, as well as changes in smolt migration patterns, on the other. This was the first occasion that a study of this type had been carried out in the Baltic Sea basin. In summer, growth of salmon parr in all age groups in the Salaca River was reduced. However, the size of smolt was found to increase. Migration of sea trout smolt in the Salaca River took place earlier, and the end of both salmon and sea trout migration was also observed earlier. The age structure of salmon smolt changed, with the one-year- old age group dominating. Judging from the total numbers of salmon and sea trout smolt in the River Salaca, production of smolt in the river during the monitoring period increased.

scholarly journals Forest fund of Vyzhivka River basin: current status and features of use

2013 ◽  
pp. 357-366
Author(s):  
Nadia Chyr ◽  
Mykhailo Melniychuk ◽  
Roman Kacharovskyi
Keyword(s):  
Environmental Management ◽  
Species Composition ◽  
River Basin ◽  
Age Structure ◽  
Economic Importance ◽  
Current Status ◽  
Forest Species ◽  
Forest Reserves ◽  
Current State ◽  
Forest Species Composition

Current state of forest fund of Vyzhivka River basin was described and evaluated. Statistics and dynamics of forest reserves and composition of tree species and age structure of forests were analyzed. Groups of forests by economic importance and the main types of environmental management within forest fund of studied area were allocated. Both negative and positive sides of it were shown. Key words: forest fund, forest species composition, age structure of forests, logging, reforestation.

Effects of marine conditions, fishing, and smolt traits on the survival of tagged, hatchery-reared sea trout (Salmo trutta trutta) in the Baltic Sea

2007 ◽  
Vol 64 (9) ◽  
pp. 1183-1198 ◽  
Author(s):  
Irma Kallio-Nyberg ◽  
Irma Saloniemi ◽  
Eero Jutila ◽  
Ari Saura
Keyword(s):  
Survival Rate ◽  
Baltic Sea ◽  
Salmo Trutta ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Survival Rates ◽  
Clupea Harengus ◽  
The Baltic Sea ◽  
Sea Trout ◽  
The Baltic

The marine survival of tagged sea trout (Salmo trutta trutta) smolt groups (n  =  236) stocked from 1970 to 2001 in the Baltic Sea was analysed using a linear mixed model. The response variable, survival rate, was associated with smolt size, release date, sea surface temperature in May, and prey fish abundance, and interactions among these factors. The effect of smolt size was in interaction with Baltic herring (Clupea harengus membras) abundance; smolt size had an optimum of about 22 cm in years when herring were abundant, but when herring were less abundant, the survival of larger smolts was higher. Early stocking in warm springs or late stocking in cold springs gave the best survival rates for trout. Changes in return activity or fishing methods have made tag returns a less reliable way of estimating survival during the last 30 years. The actual return rate of undersized fish (<40 cm) compared with their estimated proportion among captured fish decreased over time, which suggests that the survival rate for the later years was probably underestimated. It is likely that we were unable to include all the relevant explanatory variables in the model, as year effects remained significant, suggesting unknown annual variation affecting survival.

Current State of Conditions for Reproduction of the Black Sea Trout Salmo trutta labrax in the Mzymta River

2018 ◽  
Vol 58 (1) ◽  
pp. 93-103 ◽  
Author(s):  
D. S. Pavlov ◽  
A. E. Veselov ◽  
V. V. Kostin ◽  
D. A. Efremov ◽  
M. A. Ruchiev ◽  
...  
Keyword(s):  
Black Sea ◽  
Salmo Trutta ◽  
The Black Sea ◽  
Sea Trout ◽  
Current State

scholarly journals Characteristics of sea trout spawners (Salmo trutta) in the Vistula River mouth in reference to the previous Vistula River stocks

2020 ◽  
Vol 28 (3) ◽  
pp. 166-174
Author(s):  
Paweł Buras
Keyword(s):  
Age Structure ◽  
Salmo Trutta ◽  
Length Distribution ◽  
River Mouth ◽  
Spawning Grounds ◽  
Sea Trout ◽  
Vistula River ◽  
Management Interventions

AbstractThe age structure and length distribution of sea trout spawners caught in the Vistula River mouth in the 1984–1986 period were analyzed in reference to previous Vistula stocks of summer spawning and winter spawning runs, and also to silvering sea trout. The comparison took into consideration two variants: the period when the sea trout summer spawning and winter spawning runs ascended the Vistula and when they gathered at spawning grounds. Statistically significant differences were confirmed in the age structure and length distribution of sea tout spawners caught in the Vistula River mouth in the 1980s and the previous Vistula stocks. The reason for these difference must be sought in management interventions and especially in the permanent cycle of smolt production, sea trout spawner selection when they ascended the Vistula, catches made for artificial spawning, and the periodic stocking of sea trout with material originating from Pomeranian rivers.

scholarly journals Coastal migrations, temporary use of neighbouring rivers, and growth of sea trout (Salmo trutta) from nine northern Baltic Sea rivers

2012 ◽  
Vol 69 (6) ◽  
pp. 971-980 ◽  
Author(s):  
Erik Degerman ◽  
Kjell Leonardsson ◽  
Hans Lundqvist
Keyword(s):  
Baltic Sea ◽  
Salmo Trutta ◽  
Population Decline ◽  
Movement Pattern ◽  
Large Rivers ◽  
Small Rivers ◽  
Sea Trout ◽  
Management Plans ◽  
Length Increment ◽  
The Baltic

Abstract Degerman, E., Leonardsson, K., and Lundqvist, H. 2012. Coastal migrations, temporary use of neighbouring rivers, and growth of Sea trout (Salmo trutta) from nine northern Baltic Sea rivers – ICES Journal of Marine Science, 69: 971–980. The wild migratory trout (Salmo trutta) stocks in the northern Baltic Sea are threatened, and the fishery is thought to play a significant role in the population decline. Therefore, knowledge about the migration patterns of these stocks is needed to develop appropriate management plans. For this reason, we analysed the movement pattern from recaptures of mandatory releases of tagged hatchery-reared trout smolt from nine rivers in the region (1998–2007). The median time from release until recapture was 366 days, and the median migration distance at recapture was 27 km, with a dominating southward direction for northern stocks. Most of the recaptured fish were immature (65%), and recaptures in rivers (55%) dominated over recaptures along the coast (44%). Riverine recaptures were most frequent during autumn–spring. A total of 16% of all recaptures in rivers occurred in non-natal rivers. Straying was about twice as frequent among fish from small rivers as from large rivers. The results from the river Gideälven indicate that using broodstock from other rivers in stocking programmes may lead to a high proportion of strayers. In addition, temporary use of neighbouring rivers was more frequent in large rivers during winter. Growth, in terms of length increment, was high, especially in fish from southern parts of the Baltic, and higher than in neighbouring warmer and more saline sea areas.

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