Search results for "baltic Sea"
showing 10 items of 101 documents
Indice de réflexion latérale du saumon Atlantique (Salmo salar), de la truite de mer (Salmo trutta), du corégone (Coregonus lavaretus) et du brochet …
2000
L'indice de reflexion acoustique laterale (TS) de 19 saumons Atlantique (Salmo salar), 16 truites de mer (Salmo trutta), 10 coregones (Coregonus lavaretus) et 7 brochets (Esox lucius) a ete mesure en utilisant un sondeur de 200 kHz, afin d'etudier la relation entre l'indice TS et la taille, le poids et la surface du poisson. Les effets de l'angle d'incidence sur l'indice TS ont aussi ete etudies. Des modeles lineaires entre TS et le logarithme de l'indice de taille du poisson ont ete ajustes et ont montre que la meilleure prevision provient de l'indice de longueur. Classiquement, l'erreur standard de l'estimation etait de 1,2 a 2,9 dB. Les resultats des mesures de TS sur des poissons de lon…
Cormorant predation mortality of perch (Perca fluviatilis) in coastal and archipelago areas, northern Baltic Sea
2021
Abstract Perch (Perca fluviatilis) is an important prey species of the great cormorant (Phalacrocorax carbo sinensis) in the coastal waters of the northern Baltic Sea. The annual predation mortality caused by cormorants was estimated based on the consumed numbers of perch in relation to the abundance of perch in vulnerable age groups in the sea. We used existing stock assessment data (Archipelago Sea) or a simple population model in other areas (Gulf of Finland, Bothnian Sea, and Quark), based on commercial and recreational perch catches, and estimated fishing and natural mortalities, with distributions describing our understanding about the likelihood of different values for every variable…
The “Seili-index” For The Prediction of Chlorophyll-α Levels In The Archipelago Sea of The Northern Baltic Sea, Southwest Finland
2021
AbstractTo build a forecasting tool for the state of eutrophication in the Archipelago Sea, we fitted a Generalized Additive Mixed Model (GAMM) to marine environmental monitoring data, which were collected over the years 2011–2019 by an automated profiling buoy at the Seili ODAS-station. The resulting “Seili-index” can be used to predict the chlorophyll-α (chl-a) concentration in the seawater a number of days ahead by using the temperature forecast as a covariate. An array of test predictions with two separate models on the 2019 data set showed that the index is adept at predicting the amount of chl-a especially in the upper water layer. The visualization with 10 days of chl-a level predict…
High Lipid Content of Prey Fish and n−3 PUFA Peroxidation Impair the Thiamine Status of Feeding-Migrating Atlantic Salmon (Salmo salar) and Is Reflec…
2022
Signs of impaired thiamine (vitamin B1) status in feeding-migrating Atlantic salmon (Salmo salar) were studied in three Baltic Sea areas, which differ in the proportion and nutritional composition of prey fish sprat (Sprattus sprattus) and herring (Clupea harengus). The concentration of n−3 polyunsaturated fatty acids (n−3 PUFAs) increased in salmon with dietary lipids and n−3 PUFAs, and the hepatic peroxidation product malondialdehyde (MDA) concentration increased exponentially with increasing n−3 PUFA and docosahexaenoic acid (DHA, 22:6n−3) concentration, whereas hepatic total thiamine concentration, a sensitive indicator of thiamine status, decreased with th…
Benthic‐pelagic coupling and trophic relationships in northern Baltic Sea food webs
2020
Understanding marine ecosystem structure and functioning is crucial in supporting sustainable management of natural resources and monitoring the health of marine ecosystems. The current study utilized stable isotope (SI) mixing models and trophic position models to examine energy flow, trophic relationships, and benthic‐pelagic coupling between food web components. Roughly 1900 samples from different trophic levels in the food web, collected during 2001–2010 from four northern and central sub‐basins of the Baltic Sea, were analyzed for SI ratios of carbon and nitrogen. Trophic structure of the food webs among the sub‐basins was consistent, but there were differences between the proportions …
Aircraft measurements of aerosol particles and trace gases over the Southern Baltic Sea during the BALTIC'15 campaign in 2015
2019
During the BALTIC'15 campaign, conducted in August 2015 over the Southern Baltic Sea, trace gasses (CO2/O3/NOy/SO2) and aerosol particles (number concentration of total/non-volatile/Aitken mode/ Accumulation mode/Coarse mode/refractory black carbon, aerosol extinction coefficient, mass concentration of refractory black carbon were measured). Observations were performed on board of the Alfred Wegener Institute research aircraft Polar 5 during 4 flights: - Scientific flight 1 (SF1) 26 August 2015 - Scientific flight 2 (SF2) 28 August 2015 - Scientific flight 3 (SF3) 28 August 2015 - Scientific flight 4 (SF4) 30 August 2015
Holocene Spatiotemporal Redox Variations in the Southern Baltic Sea
2021
Low oxygen conditions in the modern Baltic Sea are exacerbated by human activities; however, anoxic conditions also prevailed naturally over the Holocene. Few studies have characterized the specific paleoredox conditions (manganous, ferruginous, euxinic) and their frequency in southern Baltic sub-basins during these ancient events. Here, we apply a suite of isotope systems (Fe, Mo, S) and associated elemental proxies (e.g., Fe speciation, Mn) to specifically define water column redox regimes through the Baltic Holocene in a sill-proximal to sill-distal transect (Lille Belt, Bornholm Basin, Landsort Deep) using samples collected during the Integrated Ocean Drilling Program Expedition 347. At…
Itämeren ympäristö
1751
Eero ja Erkki Fredriksonin säätiö
Skandinavia ja Itämeren ympäristö
1508
Eero ja Erkki Fredriksonin säätiö
Itämeren pohjoisosan ympäristö
1568
Eero ja Erkki Fredriksonin säätiö