Large-scale species invasion into a low-diversity system: spatial and temporal distribution of the invasive polychaetes Marenzelleria spp. in the Baltic Sea

2015 ◽  
Vol 17 (7) ◽  
pp. 2055-2074 ◽  
Author(s):  
Laura Kauppi ◽  
Alf Norkko ◽  
Joanna Norkko
Keyword(s):  
Baltic Sea ◽  
Large Scale ◽  
Temporal Distribution ◽  
Spatial And Temporal Distribution ◽  
The Baltic Sea ◽  
Species Invasion ◽  
Low Diversity ◽  
The Baltic

scholarly journals Deficiency syndromes in top predators associated with large-scale changes in the Baltic Sea ecosystem

PLoS ONE ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. e0227714 ◽  
Author(s):  
Sanna Majaneva ◽  
Emil Fridolfsson ◽  
Michele Casini ◽  
Catherine Legrand ◽  
Elin Lindehoff ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Large Scale ◽  
The Baltic Sea ◽  
Top Predators ◽  
The Baltic

scholarly journals Effect of ocean acidification and elevated <i>f</i>CO<sub>2</sub> on trace gas production by a Baltic Sea summer phytoplankton community

2016 ◽  
Vol 13 (15) ◽  
pp. 4595-4613 ◽  
Author(s):  
Alison L. Webb ◽  
Emma Leedham-Elvidge ◽  
Claire Hughes ◽  
Frances E. Hopkins ◽  
Gill Malin ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Large Scale ◽  
Gas Production ◽  
Trace Gas ◽  
Research Station ◽  
The Baltic Sea ◽  
Chl A ◽  
The Baltic ◽  
Upwelling Event ◽  
Ambient Co2

Abstract. The Baltic Sea is a unique environment as the largest body of brackish water in the world. Acidification of the surface oceans due to absorption of anthropogenic CO2 emissions is an additional stressor facing the pelagic community of the already challenging Baltic Sea. To investigate its impact on trace gas biogeochemistry, a large-scale mesocosm experiment was performed off Tvärminne Research Station, Finland, in summer 2012. During the second half of the experiment, dimethylsulfide (DMS) concentrations in the highest-fCO2 mesocosms (1075–1333 µatm) were 34 % lower than at ambient CO2 (350 µatm). However, the net production (as measured by concentration change) of seven halocarbons analysed was not significantly affected by even the highest CO2 levels after 5 weeks' exposure. Methyl iodide (CH3I) and diiodomethane (CH2I2) showed 15 and 57 % increases in mean mesocosm concentration (3.8 ± 0.6 increasing to 4.3 ± 0.4 pmol L−1 and 87.4 ± 14.9 increasing to 134.4 ± 24.1 pmol L−1 respectively) during Phase II of the experiment, which were unrelated to CO2 and corresponded to 30 % lower Chl a concentrations compared to Phase I. No other iodocarbons increased or showed a peak, with mean chloroiodomethane (CH2ClI) concentrations measured at 5.3 (±0.9) pmol L−1 and iodoethane (C2H5I) at 0.5 (±0.1) pmol L−1. Of the concentrations of bromoform (CHBr3; mean 88.1 ± 13.2 pmol L−1), dibromomethane (CH2Br2; mean 5.3 ± 0.8 pmol L−1), and dibromochloromethane (CHBr2Cl, mean 3.0 ± 0.5 pmol L−1), only CH2Br2 showed a decrease of 17 % between Phases I and II, with CHBr3 and CHBr2Cl showing similar mean concentrations in both phases. Outside the mesocosms, an upwelling event was responsible for bringing colder, high-CO2, low-pH water to the surface starting on day t16 of the experiment; this variable CO2 system with frequent upwelling events implies that the community of the Baltic Sea is acclimated to regular significant declines in pH caused by up to 800 µatm fCO2. After this upwelling, DMS concentrations declined, but halocarbon concentrations remained similar or increased compared to measurements prior to the change in conditions. Based on our findings, with future acidification of Baltic Sea waters, biogenic halocarbon emissions are likely to remain at similar values to today; however, emissions of biogenic sulfur could significantly decrease in this region.

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.

Seasonal variability of phytoplankton in the shallow waters of the southern Baltic Sea

2018 ◽  
Vol 33 (1) ◽  
pp. 9-15
Author(s):  
Iwona Zabroś ◽  
Marlena Mioskowska
Keyword(s):  
Baltic Sea ◽  
Temporal Distribution ◽  
Environmental Parameters ◽  
Spatial And Temporal Variability ◽  
Sample Collection ◽  
The Baltic Sea ◽  
Mean Values ◽  
Southern Baltic Sea ◽  
Southern Baltic ◽  
The Baltic

The Baltic Sea is characterized by a seasonal variation of phytoplankton structure. These organisms are particularly sensitive to changes in various environmental parameters. Cyclic, recurring annually fluctuation of species composition, abundance and biomass of phytoplankton is a consequence of these changes. Spatial and temporal variability of particular groups of phytoplankton is not the same in different areas of the Baltic Sea. The purpose of this work was to determine the spatial and temporal distribution of phytoplankton in three chosen areas of the coastal zone of the southern Baltic Sea (Ustka, Poddąbie and Rowy) in the period of November 2014 - September 2016. Mean values of abundance and biomass of phytoplankton for the surveyed areas were typical for this type of coastal waters. In each of the surveyed areas the same dominat species in terms of the abundance and biomass were observed. A growth of diatoms was recorded only in the area of Ustka, which could have been caused by the inflow of river waters. Seasonal surveys of phytoplankton indicated that in the case of the studies regarding this parameter – taxonomic composition, abundance and biomass in the same surveyed area were similar at the three research stations (e.g. 75-80%), depending on the season of the year. On this basis, it was concluded that, whether carrying out the monitoring of phytoplankton or planned investments, the sample collection frequency had a greater significance than the number of research stations.

Statistical Downscaling of daily extreme Sea Level with Random Forest: Examples from South-East Asia and the Baltic Sea

2020 ◽  
Author(s):  
Svenja Bierstedt ◽  
Eduardo Zorita ◽  
Birgit Hünicke
Keyword(s):  
Random Forest ◽  
Baltic Sea ◽  
East Asia ◽  
Sea Level ◽  
Large Scale ◽  
South East Asia ◽  
The Baltic Sea ◽  
Sea Levels ◽  
Extreme Sea Levels ◽  
The Baltic

&lt;p&gt;The coastlines of the Baltic Sea and Indonesia are both relatively complex, so that the estimation of extreme sea levels caused by the atmospheric forcing becomes complex with conventional methods. Here, we explore whether Machine Learning methods can provide a model surrogate to compute more rapidly daily extremes in sea level from large-scale atmosphere-ocean fields. We investigate the connections between the atmospheric and ocean drivers of local extreme sea level in South East Asia and along the Baltic Sea based on statistical analysis by Random Forest Models, driven by large-scale meteorological predictors and daily extreme sea level measured by tide-gauge records over the last few decades.&lt;/p&gt;&lt;p&gt;First results show that in some Indonesian areas extremes are driven by large-scale climate fields; in other areas they are incoherently driven by local processes. An area where random forest predicted extremes show good correspondence to observed extremes is found to be the Malaysian coastline. For the Indonesian coasts, the Random Forest Algorithm was unable to predict extreme sea levels in line with observations. Along the Baltic Sea, in contrast, the Random Forest model is able to produce reasonable estimations of extreme sea levels based on the large-scale atmospheric fields. An analysis of the interrelations of extreme sea levels in the South Asia regions suggests that either the data quality may be compromised in some regions or that other forcing factors, distinct from the large-scale atmospheric fields, may also be involved.&lt;/p&gt;

Past, current, and future freshwater inflows to the Baltic Sea under changing climate and socioeconomics

2020 ◽  
Author(s):  
Alena Bartosova ◽  
René Capell ◽  
Jørgen E. Olesen ◽  
Berit Arheimer
Keyword(s):  
Climate Change ◽  
Baltic Sea ◽  
Large Scale ◽  
Mitigation Measures ◽  
Nutrient Loads ◽  
Socioeconomic Conditions ◽  
The Baltic Sea ◽  
Nitrogen Loads ◽  
The Baltic ◽  
Freshwater Inflows

&lt;p&gt;The Baltic Sea is suffering from eutrophication caused by nutrient discharges from land to sea. These freshwater inflows vary in magnitude from year to year as well as within each year due to e.g. natural variability, weather patterns, and seasonal human activities. Nutrient transport models are important tools for assessments of macro-nutrient fluxes (nitrogen, phosphorus) and for evaluating the connection between pollution sources and the assessed water body. While understanding of current status is important, impacts from changing climate and socio-economics on freshwater inflows to the Baltic Sea also need to be taken into account when planning management practices and mitigation measures.&lt;/p&gt;&lt;p&gt;Continental to global scale catchment-based hydrological models have emerged in recent years as tools e.g. for flood forecasting, large-scale climate impact analyses, and estimation of time-dynamic water fluxes into sea basins. Here, we present results from the pan-European rainfall-runoff and nutrient transfer model E-HYPE, developed as a multi-purpose tool for large-scale hydrological analyses. We compared current freshwater inflows from land with those from dynamic modelling with E-HYPE under various climate and socioeconomic conditions. The socioeconomic conditions (land use, agricultural practices, population changes, dietary changes, atmospheric deposition, and wastewater technologies) were evaluated for 3 additional time horizons: 2050s using the Shared Socioeconomic Pathways, 1900s using historical data, and a reference period using a synthetic &amp;#8220;no human impact&amp;#8221; scenario. An ensemble of 4 climate models that preserves the range of projected changes in precipitation and temperature from a larger ensemble was selected for analysis of climate impacts in 2050s. &amp;#160;&lt;/p&gt;&lt;p&gt;We show that while climate change affects nutrient loads to the Baltic Sea, these impacts can be overshadowed by the impacts of changing socioeconomic factors. Historical nitrogen loads were estimated as 43% and 33% of the current loads for the 1900s and the &amp;#8220;no human impact&amp;#8221; scenarios, respectively. Average nitrogen loads are projected to increase by 4-10% (8% on average) as a response to climate change by 2050s. Purely mitigation measures that did not address the magnitude of the nutrient sources reduced the total nitrogen load by &lt;5%, with local efficiencies being reduced through retention processes. However, changes in the socioeconomic drivers led to significant changes in the future loads with the range of impacts spanning 30% of the current load depending on the socioeconomic pathway to be followed. This means that policy decisions have by far the largest impact when managing eutrophication in the Baltic Sea region.&lt;/p&gt;&lt;p&gt;Bartosova, A., Capell, R., Olesen, J.E. et al. (2019). Future socioeconomic conditions may have a larger impact than climate change on nutrient loads to the Baltic Sea. Ambio 48, 1325&amp;#8211;1336 doi:10.1007/s13280-019-01243-5&lt;/p&gt;

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