Search results for "BALTIC SEA"
showing 10 items of 101 documents
PCA analysis of wind direction climate in the baltic states
2021
Wind direction is one of the fundamental parameters of weather. In this study we investigate the wind direction climate 10 m above surface level in the Baltic States (Estonia, Latvia, Lithuania). The analysis of wind direction over larger regions is usually hindered by the fact that wind direction is a circular variable, which means that averaged values are meaningless. Here we show how Principal Component Analysis (PCA) can be applied to give a large scale overview of typical wind direction patterns in the region. Here we apply PCA to both observational and reanalysis data. The most significant wind direction patterns are detected in both synoptic scale and mesoscale, and we attempt to lin…
Seasonal dynamics of biomarkers in infaunal clam Macoma balthica from the Gulf of Riga (Baltic Sea)
2014
Abstract Biomarkers are often regarded as “early warning” signals of environmental pollution; however seasonal changes are mentioned as one of the most important factor that influences the activity of biomarkers. The aim of our study was to assess the importance of seasonal variation of selected contaminant biomarkers in Macoma balthica to provide background information for further environmental surveys in the Gulf of Riga. Seasonal variation of biomarkers (acetylcholinesterase (AChE), catalase (CAT), glutathione reductase (GR) and glutathione- S -transferase (GST)) was measured in infaunal clam M . balthica from the southern part of the Gulf of Riga. The majority of biomarkers (GST, CAT an…
The biocenotic value of Slitere National Park, Latvia, with special reference to inter-dune mires
2019
Inter-dune wetlands in Europe harbour many Red List species because they are very nutrient-poor ecosystems. Most of these wetlands are geologically very young and no or little peat formation has occurred. In Slītere National Park the numerous inter-dune wetlands are relatively old, up to 4500 years old, and most mire communities are peat forming and they are well preserved. However, the hydrological systems that have conserved the mires are largely unknown. In the present study we analysed 128 vegetation relevées of dune mires in order to assess the variation in ecological mire types. We also carried out several short-time studies to get an insight into the peat development and hydrological…
Baltic Sea in Estonian and Finnish media : discussed topics and stakeholders
2016
In this paper the stakeholders and most discussed topics of Baltic Sea in the media are examined. Baltic Sea is a fragile ecosystem that provides variety of services to the locals. Not only the locals hold the stake, but also industries and governments. This paper aims to present the complexity of stakeholder network and contradicting interests. Altogether 104 newspaper articles from Estonian and Finnish media on Baltic Sea were used as the data source and the concerning topics, themes and stakeholders were surveyed. The qualitative data was inserted to the textual analysis software QDA Miner 4 Lite. Three main topics were named according to the concept of three pillars of sustainability- e…
Solar PAR and UVR modify the community composition and photosynthetic activity of sea ice algae
2015
The effects of increased photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) on species diversity, biomass and photosynthetic activity were studied in fast ice algal communities. The experimental set-up consisted of nine 1.44 m(2) squares with three treatments: untreated with natural snow cover (UNT), snow-free (PAR + UVR) and snow-free ice covered with a UV screen (PAR). The total algal biomass, dominated by diatoms and dinoflagellates, increased in all treatments during the experiment. However, the smaller biomass growth in the top 10-cm layer of the PAR + UVR treatment compared with the PAR treatment indicated the negative effect of UVR. Scrippsiella complex (mainly…
Ultra-conserved elements provide insights to the biogeographic patterns of three benthic macroinvertebrate species in the Baltic Sea
2022
The Baltic Sea, with its steep salinity gradient, high water retention time, and relatively young age, represents a marginal ecosystem between marine and freshwater extremes. Due to differing invasion history and dispersal capabilities of Baltic species, there are large differences in species distributions, species-specific genetic structure and variation, and edge populations that may represent both a subset of the original population, as well as unique genetic lineages. We used a phylogenomic approach to investigate relationships between populations of three benthic macroinvertebrate species: Pygospio elegans, Corophium volutator, and Mya arenaria, providing new insight into evolutionary …
Baseline port surveys for invasive marine species in the Northeastern Baltic
2006
Marine ecosystems around the world are being transformed and degraded by non-indigenous species, which affect the structure and function of the ecosystem, causing major ecological and economic implications. Ships have been recognized as a major vector for the introduction of non-indigenous harmful organisms, carrying them in ballast water tanks and sediments. Activities to prevent and mitigate the impact of invasive alien species have to be based on cooperation. Financed by Phare Cross Border Co-operation Programme in the Baltic Sea Region (2005–2006) Latvia together with Estonia will focus on baseline port surveys for non-indigenous species in the north-eastern part of the Baltic Sea.
Proceedings of the International Conference Riga Readings in Social Sciences
2020
Conference Proceedings of the International Conference Riga Readings in Social Sciences (RRSS). The Advanced Social and Political Research Institute, Faculty of Social sciences, University of Latvia annually organizes the international scientific conference Riga Readings in Social Sciences. The 1st RRSS conference (November 23, 2017) explored different transformations of civic society and various dimensions of inequality in contemporary Europe. Key-note speeches were devoted to the different aspects of social inequality. The 2nd RRSS conference (November 22-23, 2018) Baltic Sea Region: Hundred Years On. Contributions from interdisciplinary areas of studies (regional development, human devel…
Past, present and future state of the biogeochemical Si cycle in the Baltic Sea
2008
The Baltic Sea is one of many aquatic ecosystems that show long-term declines in dissolved silicate (DSi) concentrations due to anthropogenic alteration of the biogeochemical Si cycle. Reductions i ...
Temperature-induced microstructural changes in shells of laboratory-grown Arctica islandica (Bivalvia).
2021
Bivalve shells are increasingly used as archives for high-resolution paleoclimate analyses. However, there is still an urgent need for quantitative temperature proxies that work without knowledge of the water chemistry–as is required for δ18O-based paleothermometry–and can better withstand diagenetic overprint. Recently, microstructural properties have been identified as a potential candidate fulfilling these requirements. So far, only few different microstructure categories (nacreous, prismatic and crossed-lamellar) of some short-lived species have been studied in detail, and in all such studies, the size and/or shape of individual biomineral units was found to increase with water temperat…