Tides are the main type of sea level variability in the world oceans. However, oceanic tides penetrate weakly, or do not penetrate at all, into enclosed basins such as the Baltic, Black, and Caspian seas. Consequently, only directly forced tides are formed in these basins. Long observation time series (up to 123 years in the Baltic Sea and 38 years in the Black and Caspian seas) at numerous sta...

The objective of the current study was determined chemical composition (including protein, lipid, ash and moisture) and content of minerals (Zn, Mn, Fe, Cu, Cr, Ca, Na, Mg, Mo, P, Se, K, I and F) in five fish species from the South Caspian Sea. The chemical analysis revealed that the protein content of common kilka, Caspian kutum, common carp, pike perch and golden grey mullet was 18.35%, 21.39...

The intention to increase roach (Rutilus rutilus) consumption is in focus for ecological and economic reasons in Finland. However, its safety as food has not been considered comprehensively. We collected and artificially digested 85 roach halves originating from the south-eastern coast of Finland, and found trematode metacercariae in 98.8% of the samples. Based on polymerase chain reaction (PCR...

According to the immunocompetence handicap hypothesis, males with attractive sexual ornamentation are more handicapped than their less ornamented rivals because of the immunosuppressive androgens required for the production of secondary sexual characters. Here we studied the predictions of the hypothesis in a wild cyprinid fish, the roach (Rutilus rutilus). We assayed (1) sexual ornamentation (...

Understanding historical roles of species in ecosystems can be crucial for assessing long term human impacts on environments, providing context for management or restoration objectives, and making conservation evaluations of species status. In most cases limited historical abundance data impedes quantitative investigations, but harvested species may have long-term data accessible from hunting r...

Ponto-Caspian gobies are a flock of five invasive fish species that have colonized freshwaters and brackish waters in Europe and North America. One of them, the round goby Neogobius melanostomus, figures among the 100 worst invaders in Europe. Current methods to detect the presence of Ponto-Caspian gobies involve catching or sighting the fish. These approaches are labor intense and not very sen...

The Ponto-Caspian (Black and Caspian seas) brackish-water fauna represents a special case of the endemic diversification in world's ancient lakes; it also involves a hotspot of continental diversity in the predominantly marine mysid crustaceans. We explored the origins and history of the mysid diversification in a phylogenetic analysis of some 20 endemic Ponto-Caspian species mainly of the genu...

In the present investigation flocculation of dissolved Cu, Zn, Pb, Ni and Mn in a series of mixtures with salinities ranging from 1.5 to 9.5% during mixing of Talar river water with the Caspian Sea water was studied. The flocculation trend of Zn (87.22%) >Mn (45.31%) >Pb (39.09%) >Cu (36.58%)>Ni (12.70%) indicates that Cu, Zn, Pb and Mn have non-conservative behavior and Ni has relatively conse...

1.1 Caspian Sea The complex history of the Caspian Sea formation has lead to a variety of different habitats. Like Australia, the Caspian Sea became isolated thousands of years ago (Plate 1). This isolation led to the speciation of many rare animals in particular the sturgeon. The Caspian Sea is the biggest enclosed body of water on Earth, having an even larger area than that of the American Gr...

In this paper we study the topology of the configuration space of a device with d legs (alias ’roach’) such that at most k of them are allowed to be off the ground. We suggest control strategies providing that this roach moves stably forward starting from a ’maximal’ subset of admissible initial positions of legs. The meaning of the term ’maximal’ will be explained below. Advantages of the sugg...