Itämeren erityispiirteistä ja haavoittuvuudesta

Itämerta on usein sanottu poikkeuksellisen haavoittuvaksi ympäristöksi. Haavoittuvuuden voi sanoa olevan eräs merialueen erityispiirteistä. </p

Itämeren muuttuva ekosysteemi

Itämeri ei ole koskaan ollut vakaa. Se syntyi aikoinaan ilmastonmuutoksen takia. Viimeisen kolmensadan vuoden aikana todettu talvien lämpeneminen voi yhtä aikaa aiheutua luonnollisesta, jääkauden jälkeisestä lämpenemisestä ja ihmisen aiheuttamasta ilmastonmuutoksesta. Globaalit ilmastomallit eivät ota huomioon alueellisia erityispiirteitä, esimerkiksi jääkauden jälkivaikutuksia Pohjois-Euroopassa. Itämeren alueen ilmastonmuutos tulee siksi olemaan intensiivisempi ja nopeampi kuin mitä globaalit mallit ennustavat. Monet viime vuosina aikasarjatutkimuksissa havaitut ympäristömuutokset esiintyvät myös ihmisen aiheuttaman ilmastonmuutoksen seurauksien luettelossa

Selective planktivory - effect on vertical migration and life-cycle parameters of zooplankton

Sisältää myös kolme muuta artikkelia: Kaisa Kononen, Åke Niemi: Variation in phytoplankton and hydrography in the outer archipelago at the entrance to the Gulf of Finland in 1968–1975 Kimmo K. Kahma: On prediction of fetch-limited wave spectrum in a steady wind E.M. Emelyanov: Basins of the Baltic Sea - traps for element

Seilin tutkimukset ovat kansallisesti tärkeitä

Merellisen ravintoketjun huipulla ovat linnut ja ihminen, kuvassa lapintiira ja lapset, joiden hyvinvointi riippuu luonnontilaisesta merestä. Planktonien, äyriäisten, vesikasvien, kalojen, lintujen ja nykyään myös puutiaisten elämän ja kuoleman tutkimus ovat olleet Seilin tutkimuslaitoksen ydintä jo 70 vuoden ajan.</p

Morphological abnormalities in gonads of the Baltic herring (Clupea harengus membras) in the northern Baltic Sea.

Reproductive disorders are a major environmental concern in the Baltic Sea, due to heavy anthropogenic influence and long- and short-term variations taking place in the natural environment. We report here an increasing prevalence of gonadal malformations in the Baltic herring (Clupea harengus membras),a key species of the Baltic ecosystem and important in commercial fishery.</p

Formation of lipid reserves, fatty acid composition and reproduction of Limnocalanus macrurus (Copepoda, Calanoida) during summer in the Bothnian Sea, northern Baltic Sea

Limnocalanus macrurus is a cold-stenothermic copepod that in the Baltic Sea occurs abundantly in low-salinity areas, such as the Bothnian Bay and the Bothnian Sea, where it is one of the most important species of the pelagic ecosystem. Projections for the future of the Baltic Sea suggest that a further decline of salinity will enable the species to expand its distribution southward to the Central Baltic, where it eventually could replace copepod species, e.g. Pseudocalanus acuspes, having higher salinity requirements. Lipids may get a central role in this process as they are crucial in the production and transfer of energy in the food webs. We studied the formation of the lipid reserves in L. macrurus in the Bothnian Sea, with a special emphasis on the fatty acid composition in reproductive adults and their potential food. Our primary interest was the spring and summer season, as it is the main production and feeding period of the plankton community in the southern Bothnian Sea. The study was started at the time of the spring bloom of phytoplankton during May and it was continued until September, when the plankton production ceases.</p

Plastic debris composition and concentration in the Arctic Ocean, the North Sea and the Baltic Sea

Neuston samples were collected with a Manta trawl in the rim of the Arctic Ocean, in the Northern Atlantic Ocean and the Baltic Sea at eleven coastal and open-sea locations. All samples contained plastics identified by FTIR microscopy. Altogether, 110 microplastics pieces were classified according to size, shape, and polymer type. The concentrations at the locations were generally low (x̅ = 0.06, SD ± 0.04 particles m−3) as compared to previous observations. The highest concentrations were found towards the Arctic Ocean, while those in the Baltic Sea were generally low. The most abundant polymer type was polyethylene. Detected particle types were mainly fragments. The number of films and fibers was very low. The mean particle size was 2.66 mm (SD ± 1.55 mm). Clustering analyses revealed that debris compositions in the sea regions had characteristic differences possibly reflecting the dependences between compositions, drifting distances, sinking rates, and local oceanographic conditions.</p