Long-term modeling of large-scale nutrient cycles in the entire Baltic Sea

2009 ◽  
pp. 209-224 ◽  
Author(s):  
Oleg P. Savchuk ◽  
Fredrik Wulff
Keyword(s):  
Baltic Sea ◽  
Large Scale ◽  
Nutrient Cycles

Long-term modeling of large-scale nutrient cycles in the entire Baltic Sea

Hydrobiologia ◽  
2009 ◽  
Vol 629 (1) ◽  
pp. 209-224 ◽  
Author(s):  
Oleg P. Savchuk ◽  
Fredrik Wulff
Keyword(s):  
Baltic Sea ◽  
Large Scale ◽  
Nutrient Cycles

scholarly journals A century of genetic homogenization in Baltic salmon—evidence from archival DNA

2021 ◽  
Vol 288 (1949) ◽  
Author(s):  
Johan Östergren ◽  
Stefan Palm ◽  
John Gilbey ◽  
Göran Spong ◽  
Johan Dannewitz ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Large Scale ◽  
Isolation By Distance ◽  
Anthropogenic Impacts ◽  
Genetic Change ◽  
Past Century ◽  
The Baltic Sea ◽  
The Baltic ◽  
Archival Dna

Intra-species genetic homogenization arising from anthropogenic impacts is a major threat to biodiversity. However, few taxa have sufficient historical material to systematically quantify long-term genetic changes. Using archival DNA collected over approximately 100 years, we assessed spatio-temporal genetic change in Atlantic salmon populations across the Baltic Sea, an area heavily impacted by hydropower exploitation and associated with large-scale mitigation stocking. Analysis was carried out by screening 82 SNPs in 1680 individuals from 13 Swedish rivers. We found an overall decrease in genetic divergence and diminished isolation by distance among populations, strongly indicating genetic homogenization over the past century. We further observed an increase in genetic diversity within populations consistent with increased gene flow. The temporal genetic change was lower in larger wild populations than in smaller wild and hatchery-reared ones, indicating that larger populations have been able to support a high number of native spawners in relation to immigrants. Our results demonstrate that stocking practices of salmon in the Baltic Sea have led to the homogenization of populations over the last century, potentially compromising their ability to adapt to environmental change. Stocking of reared fish is common worldwide, and our study is a cautionary example of the potentially long-term negative effects of such activities.

scholarly journals The dilemma of controlling cultural eutrophication of lakes

2012 ◽  
Vol 279 (1746) ◽  
pp. 4322-4333 ◽  
Author(s):  
David W. Schindler
Keyword(s):  
Large Scale ◽  
Ecosystem Processes ◽  
Nutrient Fluxes ◽  
Nutrient Cycles ◽  
Case Histories ◽  
Short Term ◽  
Ecosystem Responses ◽  
Lake Recovery ◽  
Recent Claim

The management of eutrophication has been impeded by reliance on short-term experimental additions of nutrients to bottles and mesocosms. These measures of proximate nutrient limitation fail to account for the gradual changes in biogeochemical nutrient cycles and nutrient fluxes from sediments, and succession of communities that are important components of whole-ecosystem responses. Erroneous assumptions about ecosystem processes and lack of accounting for hysteresis during lake recovery have further confused management of eutrophication. I conclude that long-term, whole-ecosystem experiments and case histories of lake recovery provide the only reliable evidence for policies to reduce eutrophication. The only method that has had proven success in reducing the eutrophication of lakes is reducing input of phosphorus. There are no case histories or long-term ecosystem-scale experiments to support recent claims that to reduce eutrophication of lakes, nitrogen must be controlled instead of or in addition to phosphorus. Before expensive policies to reduce nitrogen input are implemented, they require ecosystem-scale verification. The recent claim that the ‘phosphorus paradigm’ for recovering lakes from eutrophication has been ‘eroded’ has no basis. Instead, the case for phosphorus control has been strengthened by numerous case histories and large-scale experiments spanning several decades.

scholarly journals Freight Flows in the Baltic Seaports of Russia: Factors, Trends and Perspective

2021 ◽  
Vol 17 (4) ◽  
pp. 168-185
Author(s):  
Irina Boyko ◽  
Keyword(s):  
Supply Chain ◽  
Baltic Sea ◽  
Large Scale ◽  
Special Focus ◽  
Factors Affecting ◽  
The World ◽  
Sea Ports ◽  
The Baltic ◽  
The Impact

The volatility of the exogenous conjuncture has been increasingly affecting the Russian Baltic sea ports economics in terms of freight flows dynamics, destinations and commodity items share. The methodological distinction between the notion of ‘freight turnover’ and ‘freight flow’ is given for specification of the port activity, measured in qualitative indicators, consistent with the supply chain peculiarity on the contrary of the quantitative indicators, measured in tons. The classification of the factors, affecting the freight flows is represented as well. The freight turnover at the Russian Baltic ports has been gradually dropping. The unfavorable political conditions as well the world economy and trade downturns are not the only main reasons. The research is focused on the dynamics and structure of the freight flows at the Russian Baltic sea ports under the impact of political, ecological and economic factors, when the COVID-19 pandemic reveals the main ‘bottlenecks’ of their current economics and entails the global supply chain disruption. The ongoing global economic crisis results in the world trade squeezing, causes trade conflicts and increase the cases when trade became unfair practice in the political deals. The author of the article makes a special focus on the raw resource freight turnover specialization of the Russian sea ports as one of the most critical characteristics. In a time of growing risks and uncertainty large scale investments with the long term return into development of port facilities and port construction should be thoroughly analyzed. The author concludes that the freight redirection from the European sea ports to the Russian sea ports, located on Baltic Sea, will have positive, however, short-term, effect. The long term sustainability of the Russian Baltic sea ports will be determined by the reduction of the raw resources dependence and diversification of the freight flows, which also means increasing the share of cabotage and containerized cargo

Early spring SST distribution in the Baltic Sea: in search of the coldest water

2020 ◽  
Author(s):  
Tatiana Bukanova ◽  
Irina Chubarenko
Keyword(s):  
Baltic Sea ◽  
Large Scale ◽  
Basic Research ◽  
Early Spring ◽  
Heat Fluxes ◽  
The Black Sea ◽  
The Baltic Sea ◽  
Convergence Zones ◽  
The Baltic

<p>We examine three hypotheses of formation of waters of the Cold Intermediate Layer (CIL) in the Baltic Sea: the coldest baltic waters are formed (1) at the beginning of spring warming in the Arkona and Bornholm basins, (2) in the centers of mesoscale vortexes (similar to those in the Black Sea), and (3) in the convergence zones of alongshore fronts while cooling over shelves (as in the Mediterranean Sea).</p><p>In search of the coldest surface water we analyzed the dynamics of sea surface temperature (SST) in the Baltic Proper for February-April 2003-2019 from satellite imagery of infrared sensors (MODIS-Terra/Aqua and VIIRS-Suomi-NPP), and microwave sensors (AMSR-E-Aqua, AMSR-2-GCOM-W1, and WindSat-Coriolis).</p><p>Long-term mean SST maps (for February, March, April 2003-2019) show patterns that indicate rather quick, abrupt re-structuring of thermohaline fields in late March - early April, especially evident in the Arkona and Bornholm basins. This supports the idea that seasonal transfer from two-layered winter-time vertical water stratification to the summer-time three-layered stratification is driven in the Baltic Sea not by the direct heat fluxes through the surface, but rather by the large-scale north-south water exchange.</p><p>Coastal fronts may persist for a few weeks, however their location is changeable. Stable frontal zones and vortexes are not observed under long-term SST averaging. However the sequential warming of waters from south to north direction due to geographical reasons is clearly seen with long-term averaging.</p><p>The features of spring differential warming development above shallows and along shore can be observed only from daily SST maps (not from annually averaged maps).</p><p>Investigations are supported by the Russian Foundation for Basic Research, grant No. 19-05-00717 (in part of data analysis) and the State Assignment No 0149-2019-0013 (in part of satellite data collecting and processing).</p>

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

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