No abstract

We report cross-shore profile evolution at Palanga, eastern Baltic Sea, where short period waves dominate. Cross-shore profile studies began directly after a significant coastal erosion event caused by storm “Anatol”, in December of 1999, and continued for a year. Further measurements were undertaken sixteen years later. Cross-shore profile changes were described, and cross-shore transport rates were calculated. A K-means clustering technique was applied to determine sections of the profile with the same development tendencies. Profile evolution was strongly influenced by the depth of closure which is constrained by a moraine layer, and the presence of a groyne. The method used divided the profile into four clusters: the first cluster in the deepest water represents profile evolution limited by the depth of closure, and the second and third are mainly affected by processes induced by wind, wave and water level changes. The most intensive sediment volume changes were observed directly after the coastal erosion event. The largest sand accumulation was in the fourth profile cluster, which includes the upper beach and dunes. Seaward extension of the dune system caused a narrowing of the visible beach, which has led to an increased sand volume (accretion) being misinterpreted as erosion

The aim of this study was to reveal the patterns of structural and quantitative alterations of the plankton communities along the Nemunas River-Curonian Lagoon transition of the south-eastern Baltic Sea. Authors hypothesised the influence of the different phases of the seasonal plankton development (Bacillariophyceae vs. Cyanobacteria dominance) on the response of plankton communities due to hydrodynamic forcing. In order to assess spatial patterns of physical forcing, we used sediment grain size distribution data as a proxy for hydrodynamic regime. Zooplankton and phytoplankton communities in the Nemunas River were sampled to obtain a point of reference for their structure and seasonal dynamics. The changes in sediment grain size distributions, quantitative and structural alterations in zooplankton communities, as well as structural trends in phytoplankton communities were detected in the Nemunas River-Curonian Lagoon transition area. However, the expected abundance trend was not observed in the phytoplankton community, even during the Cyanobacteria-dominated period. Despite the observed gradient of the sediment structure along the river-lagoon transition, the expected value of the sediment characteristics for the pelagic conditions was not statistically proved.

Using the bathymetry information available from historical maps, the  underwater slope of the  Baltic Sea in the  Lithuanian area of the  shore is analysed south and north of the  Klaipėda harbour. For this purpose, the old depth measurements have been converted into the metric system and cross profiles of the nearshore drawn, as well as, on this basis, the diagrams for the 3, 5, 7 and 10 m depth points have been constructed. The depth data from the maps compiled in 1743, 1855, 1875 and 1913 have been analysed. These periods correspond to specific conditions of the shore zone morpho- and litho-dynamics. In 1743 there was no beach protecting the dune ridge on the Curonian Spit, and sand was driven by wind from the shore zone to the large dunes. There were no hydro-engineering structures in the  Klaipėda harbour; therefore nothing impeded sand migration along the shore. In 1855 the shores of the Klaipėda channel were fixed, but there were no harbour piers yet. In 1875, the piers were freshly built and a beachprotecting dune ridge partly formed. In 1913, this dune ridge was already finished and the Klaipėda port was fully functioning with 5–6 m depths at the port gates. Conclusions are made about the former bottom relief during different stages of the nearshore evolution and about the conditions which caused its changes.

No abstract