Spatial and temporal variability of a dinoflagellate-cyanobacterium community under a complex hydrodynamical influence:a case study at the entrance to the Gulf of Finland

Variability of nutrients and pelagic biological parameters (primary production and chlorophyll a [chl a] in flagellate and cyanobacterial size fractions, nitrogen fixation, phytoplankton species abundance) was followed for 12 d in July 1996 at an anchor station at the entrance to the Gulf of Finland, Simultaneously, meso-scale physical fields and plankton distribution were mapped over the surrounding 15 x 30 km area. The study period coincided with the intense blooming of a dinoflagellate Heterocapsa triquetra Ehrenberg and cyanobacterium Aphanizomenon flos-aquae (Linné) Ralfs community. A complex background of hydrodynamical processes was observed in the study area, including downwelling, formation and development of an anticyclonic eddy and jet currents. Our hypothesis was that the horizontal scale of patches decreases and the variation of biological parameters increases when moving from the overall community level (chl a) to the size class level and further to the species level. The horizontal distribution of chl a was closely related to the different water masses, but the distribution of the 2 dominant species differed and showed high variability even within water masses. The temporal variability of the pelagic biological parameters at the anchor station (estimated by the coefficient of variation) was between 25 and 95 % and it may be explained by horizontal patchiness. The results confirmed our hypothesis by showing that the coefficient of variation of summational parameters (total chl a, total primary production) was always lower than that of parameters specific to plankton size (chl a and primary production in 20 pm size classes), functional group (diazotrophs) or species. Phytoplankton in the size range equal to or greater than 20 μm exhibited particularly pronounced variability, while the smaller size fractions were less affected

Ethnic Minority–Majority Unions in Estonia

Ethnic minority–majority unions—also referred to as mixed ethnic unions—are often seen as the ultimate evidence of the integration of ethnic minorities into their host societies. We investigated minority–majority unions in Estonia, where ethnic minorities account for one-third of the total population (Russians 26%, followed by Ukrainians, Byelorussians, Finns and other smaller groups). Using data from the 2000 Estonian census and regression models, we found that Slavic women are less likely to be in minority–majority unions than are members of other minority groups, with Russians being the least likely. Finns, who are culturally most similar to the Estonian majority population, are the most likely to form a union with an Estonian. For ethnic minority women, the likelihood of being in minority–majority unions is highest in rural areas and increases over generations, with third-generation immigrants being the most likely. Estonian women are most likely to have a minority partner when they or their parents were born abroad and when they live in urban areas. Our findings suggest that both the opportunity to meet potential partners and openness to other ethnic groups are important factors for understanding the dynamics of minority–majority unions

Observations of Stratified Turbulence Depending on the Different Wind, Strtification and Shear Scenarios.

Abstract not availableJRC.(SAI)-Space Application Institut

Flow, waves and water exchange in the Suur Strait, Gulf of Riga, in 2008

Wind, flow and wave measurements were performed in November–December in 2008 in the relatively narrow and shallow Suur Strait connecting the waters of the V¨ainameri and the Gulf of Riga. During the measurement period wind conditions were extremely variable, including a severe storm on 23 November. The flow speed along the strait varied between ±0.2 m s−1, except for the 0.4 m s−1 that occurred after the storm as a result of the sea level gradient. The mean and maximum significant wave heights were 0.53 m and 1.6 m respectively. Because of their longer fetch, southerly winds generated higher waves in the strait than winds from the north. All wave events caused by the stronger southerly winds induced sediment resuspension, whereas the current-induced shear velocity slightly exceeded the critical value for resuspension only when the current speed was 0.4 m s−1. A triplenested two-dimensional high resolution (100 m in the Suur Strait) circulation model and the SWAN wave model were used to simulate water exchange in 2008 and the wave-induced shear velocity field in the Suur Strait respectively. Circulation model simulations demonstrated that water exchange was highly variable, that cumulative transport followed an evident seasonal cycle, and that there was an gross annual outflow of 23 km3 from the Gulf of Riga. The horizontal distribution of waveinduced shear velocity during the strong southerly wind event indicated large shear velocities and substantial horizontal variability. The shear velocities were less than the critical value for resuspension in the deep area of the Suur Strait