scholarly journals Modeling point and non-point nutrient fluxes in river systems of lake Peipsi drainage basi

2019 ◽  
pp. 389-398
Author(s):  
Kristjan Piirimäe
Keyword(s):  
Large Scale ◽  
Sharp Decrease ◽  
Paper Analysis ◽  
Cyanobacterial Blooms ◽  
Nutrient Loads ◽  
Lake Peipsi ◽  
Baltic Sea Region ◽  
Long Term Trends ◽  
The Baltic

N and P compounds work as key elements causing bioproduction and eutrophication inwater bodies of the Baltic Sea region, A large-scale dynamic GIS-embedded PolFlowmodel considers all point and diffuse emission sources in a river basin simulating alsotransport and retention of nutrients in time steps of five years, This modeling approachwas originally developed for simulating past and present nutrient loads for the Rhine andElbe rivers. In addition, a statistical model MESAW was employed for nutrient sourceapportionment and emission estimations. This paper analysis the modeling results in LakePeipsi basin, shared by Estonia, Russia and Latvia, for long-term trends since 1985 till1999. Results of modeling, as well as monitoring data indicate quite stable long-term Pload while agricultural N load has decreased significantly in connection with dramaticchanges in agricultural structures. That, in turn, has lead to sharp decrease ofN/P ratio inriverine runoff while in lakes (L Peipsi, L Vortsjii.rv) and coastal seas, NIP ratio hasdropped below 10. These changes, enhancing cyanobacterial blooms, have significantlyworsened the ecological state of these water bodies, in the conditions of decreasedemissions. The paper concludes that wastewater treatment should focus on better removalofphosphorus.

scholarly journals The climate in the Baltic Sea region during the last millennium simulated with a regional climate model

2012 ◽  
Vol 8 (5) ◽  
pp. 1419-1433 ◽  
Author(s):  
S. Schimanke ◽  
H. E. M. Meier ◽  
E. Kjellström ◽  
G. Strandberg ◽  
R. Hordoir
Keyword(s):  
Baltic Sea ◽  
Climate Model ◽  
Regional Climate ◽  
Last Millennium ◽  
Nutrient Loads ◽  
The Baltic Sea ◽  
Baltic Sea Region ◽  
The Baltic ◽  
The Impact

Abstract. Variability and long-term climate change in the Baltic Sea region is investigated for the pre-industrial period of the last millennium. For the first time dynamical downscaling covering the complete millennium is conducted with a regional climate model in this area. As a result of changing external forcing conditions, the model simulation shows warm conditions in the first centuries followed by a gradual cooling until ca. 1700 before temperature increases in the last centuries. This long-term evolution, with a Medieval Climate Anomaly (MCA) and a Little Ice Age (LIA), is in broad agreement with proxy-based reconstructions. However, the timing of warm and cold events is not captured at all times. We show that the regional response to the global climate anomalies is to a strong degree modified by the large-scale circulation in the model. In particular, we find that a positive phase of the North Atlantic Oscillation (NAO) simulated during MCA contributes to enhancing winter temperatures and precipitation in the region while a negative NAO index in the LIA reduces them. In a second step, the regional ocean model (RCO-SCOBI) is used to investigate the impact of atmospheric changes onto the Baltic Sea for two 100 yr time slices representing the MCA and the LIA. Besides the warming of the Baltic Sea, the water becomes fresher at all levels during the MCA. This is induced by increased runoff and stronger westerly winds. Moreover, the oxygen concentrations in the deep layers are slightly reduced during the MCA. Additional sensitivity studies are conducted to investigate the impact of even higher temperatures and increased nutrient loads. The presented experiments suggest that changing nutrient loads may be more important determining oxygen depletion than changes in temperature or dynamic feedbacks.

scholarly journals The climate in the Baltic Sea region during the last millennium

2012 ◽  
Vol 8 (2) ◽  
pp. 1369-1407 ◽  
Author(s):  
S. Schimanke ◽  
H. E. M. Meier ◽  
E. Kjellström ◽  
G. Strandberg ◽  
R. Hordoir
Keyword(s):  
Baltic Sea ◽  
Dynamical Downscaling ◽  
Ice Age ◽  
Last Millennium ◽  
Nutrient Loads ◽  
The Baltic Sea ◽  
Baltic Sea Region ◽  
The Baltic ◽  
The Impact

Abstract. Variability and long-term climate change in the Baltic Sea region is investigated for the pre-industrial period of the last millennium. For the first time dynamical downscaling covering the complete millennium is conducted with a regional climate model in this area. As a result of changing external forcing conditions the model simulation shows warm conditions in the first centuries followed by a gradual cooling until c. 1700 before temperature increases in the last centuries. This long-term evolution, with a Medieval Climate Anomaly (MCA) and a Little Ice Age (LIA), is in broad agreement with proxy-based reconstructions. However, the timing of warm and cold events is not captured at all times. We show that the regional response to the global climate anomalies is to a strong degree modified by the large-scale circulation in the model. In particular, we find that a positive NAO-phase simulated during MCA contributes to enhancing winter temperatures and precipitation in the region while a negative NAO-anomaly in the LIA reduces them. In a second step, the regional ocean model RCO is used to investigate the impact of atmospheric changes onto the Baltic Sea for two 100 yr time slices representing the MCA and the LIA. Besides the warming of the Baltic Sea the water becomes fresher at all levels during the MCA. This is induced by increased runoff and stronger westerly winds. Moreover, the oxygen concentrations in the deep layers are slightly reduced during the MCA. Additional sensitivity studies are conducted to investigate the impact of even higher temperatures and increased nutrient loads. The presented experiments suggest that changing nutrient loads may be more important determining oxygen depletion than changes in temperature or dynamic feedbacks.

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 Long-term trends in Secchi depth in the Baltic Sea

1996 ◽  
Vol 41 (2) ◽  
pp. 346-351 ◽  
Author(s):  
Per Sandén ◽  
Bertil Håkansson
Keyword(s):  
Baltic Sea ◽  
Secchi Depth ◽  
The Baltic Sea ◽  
Long Term Trends ◽  
The Baltic

Characteristics of natural neutron radiation background performed within the BSUIN project.

2020 ◽  
Author(s):  
Karol Jedrzejczak ◽  
Marcin Kasztelan ◽  
Jacek Szabelski ◽  
Przemysław Tokarski ◽  
Jerzy Orzechowski ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Background Radiation ◽  
Neutron Radiation ◽  
Radiation Background ◽  
Term Operation ◽  
Baltic Sea Region ◽  
Wide Range ◽  
The Baltic

<p>The BSUIN (Baltic Sea Underground Innovation Network) aims to enhance the accessibility of the underground laboratories in the Baltic Sea region for innovation, business and science. One of the BSUIN project activities is characterization of natural background radiation (NBR) in underground facilities. A specific type of NRB is neutron radiation, whose measurement requires specific instruments and long-term exposure in-situ, in heavy underground conditions.</p><p>In this talk the method of natural neutron radiation background will be presented as well as results of pilot measurements in several underground locations. In order to make this measurements, a measuring setup was designed and made. The setup design is closely matched to the task: the setup is scalable in a wide range, completely remotely controlled (via the Internet) and capable of long-term operation (months).</p><p>The pilot measurements were performed in Callio Lab, Pyhäsalmi, Finland, (4100 m w.e.), in Reiche Zeche mine in Freiberg, Germany (410 m w.e.) and in Experimental Mine “Barbara” in Mikołów, Poland (100 m w.e).</p>

scholarly journals Nitrogen and the Baltic Sea: Managing Nitrogen in Relation to Phosphorus

2001 ◽  
Vol 1 ◽  
pp. 371-377 ◽  
Author(s):  
R. Elmgren ◽  
U. Larsson
Keyword(s):  
Stakeholder Participation ◽  
Minimum Cost ◽  
Cyanobacterial Blooms ◽  
Nutrient Loads ◽  
Surface Salinity ◽  
Amenity Values ◽  
Large N ◽  
Filamentous Macroalgae ◽  
Baltic Proper ◽  
The Baltic

The Baltic is a large, brackish sea (4 x 105 km2) extending from 54ÅN to ~66ÅN, with a fourfold larger drainage area (population 8 x 107). Surface salinity (2 to 8 PSU) and hence biodiversity is low. In the last century, annual nutrient loads increased to 106metric tons N and 5 x104ton P. Eutrophication is evident in the N-limited south, where cyanobacteria fix 2 to 4 x 105ton N each summer, Secchi depths have been halved, and O2-deficient bottom areas have spread. Production remains low in the P-limited north. In nutrient-enriched coastal areas, phytoplankton blooms, toxic at times, and filamentous macroalgae reduce amenity values. Loads need to be reduced of both N, to reduce production, and P, to limit N-fixing cyanobacterial blooms. When large N-load reductions have been achieved locally, algal biomass has declined. So far, P loads have been reduced more than N loads. If this continues, a P-limited Baltic proper may result, very different from previous N-limited conditions. Reaching the management goal of halved anthropogenic N and P loads at minimum cost will require better understanding of biogeochemical nutrient cycles, economic evaluation of proposed measures, and improved stakeholder participation.

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