FEEDING OF THE INVASIVE ROUND GOBY Neogobius melanostomus (Perciformes: Gobiidae) IN THE SOUTH-EASTERN BALTIC

The feeding of the Ponto-Caspian invasive round goby Neogobius melanostomus in the coastal zone of the Baltic Sea near the Curonian Spit, in the Vistula Lagoon and in the eastern part of the Gdansk Bay has been studied. The round goby in coastal waters prefers biotopes with various shelters - boulders, large pebbles, etc. In the diet of the round goby, there is a significant proportion of fouling organisms inhabiting these objects. If fouling organisms are absent for some reason, the goby switches to other types of prey: molluscs, free-living crustaceans, insect larvae and other groups of benthic and nektobenthic organisms. There is a connection between the food spectrum and the size of the round goby: large individuals consume larger prey. The round goby implements a food strategy, which consists in the fact that all organisms that are available territorially and in size are used for food. Such food plasticity is one of the reasons for the wide expansion of this species outside the native range.

‘Silencing’ the border as a strategy to conceal the ‘other’ side: the case of the Curonian Spit

Borders do not have to be visible to be effective. However, the ways they are marked in the landscape, and the relation of these manifestations to broader border regimes and practices are questioned by border researchers and other scholars. Building physical barriers is often used to conceal the ‘other’ side, while reducing border manifestations mostly reveals the other. In this article, a hybrid border management strategy of ‘silencing’ the border (reducing border manifestations) to conceal the other side is discussed, drawing on the case study conducted at the borderland in the Curonian Spit (Russia–Lithuania). Based on a mixed method approach, but especially focussing on the visual data, this study investigates how the border splitting the peninsula in half, is latent in the landscape and in the narratives of the locals. It proposes that the border is silenced and the other is concealed on both sides because of the lack of cross-border coordination of the shared landscape and heritage. This resonates with the experiences and understandings of borderland inhabitants, this research shows. It proposes a view on border hybridity, which challenges the dominant ways of understanding borders, their functions and impact on space and on different borderland actors.

SEASONAL VARIATIONS IN THE CONTENT OF MICROPLASTIC PARTICLES IN THE SANDS OF THE BEACH SWASH ZONE

The paper considers the seasonal dynamics of the content of microplastic particles with a size from 0.5 to 5 mm in the sands of the surf zone of the Vistula Spit (the Baltic Sea). Microplastic particles are classified by size and color. The results are compared with the data for the Curonian Spit. It is concluded that the level of contamination with small microplastics (0.5–2 mm) of the sands of the swash zone can be used as a "background" value for the entire region and during all seasons of the year. The current level of sand contamination in the wave swash zone in the South-Eastern Baltic by small microplastic particles (0.5–2 mm) is 30–60 pieces per kg of dry weight throughout the year, while more than 90% are fibers.

New genetically distinct phytoplasmas and insect carriers associated with pine tree disease revealed by a survey in Curonian Spit, Lithuania

Our previous studies reported that phytoplasma was the causative agent of the pine disease in Curonian spit, Lithuania. In this study, insects from diseased pine trees and their adjacent areas were collected from 2016 to 2019 to further identify potential insect vectors that spread phytoplasmas. A total of 1018 phloem-feeding insects (order Hemiptera) were identified, 98.62% of which were aphids (Aphididae), and no known phytoplasma vectors were found. Results from semi-nested PCR using phytoplasma-universal primers revealed that phytoplasmas were detected in scots pine aphids (Cinara pini), waxy grey pine needle aphids (Cinara pineti), and species-unknown aphids. Further sequence analysis and virtual RFLP analysis of aphid-harbored phytoplasma strains indicated that they were closely related to ‘Candidatus Phytoplasma pini’ (16SrXXI-A), but mainly 16SrXXI-A variants, which were also main strains identified in diseased pine trees. In addition, three new phytoplasma subgroups were delineated in the present study. Subgroups 16SrXXI-C and 16SrXXI-D were unveiled from previously identified (but classification was overlooked) Lithuanian pine phytoplasma strains. Subgroup 16SrXXI-E was discovered from the newly identified aphid-harbored phytoplasmas. Further transmission trial study on these aphids will provide insights into the epidemiology, and pathosystem of pine phytoplasma diseases, as well as the disease management.

NATURAL FEATURES AND ANTHROPOGENIC FACTORS OF THE CURONIAN SPIT ECOSYSTEM FORMATION

The article shows history of the unique eolian coastal-marine complexes of the Curonian Spit development. The leading role of the Baltic Sea sea level fluctuations and wind activity in the formation of the spit is emphasized. Attention is paid to the territory development resuted in almost total destruction of the vegetion cover and transformation of the Curonian Spit into a sandy desert by the end of the 18th century. A variety of nature conservation measures to create the cultural landscape of the peninsula is highlighted. A modern landscape structure of the Curonian Spit is presented. The spit has the status of a National Park and is included in the UNESCO World Heritage List.

Traditional Vernacular Buildings, Architectural Heritage and Sustainability

The article is focused on vernacular dwellings in different parts of Europe: southern Italy and Lithuania that have their own traditions. The authors note that the attitude towards traditional vernacular architecture has largely changed due to ongoing research in this domail. Nevertheless, despite persistent continuity of traditional architecture, vernacular architecture was affected by the rise and development of modernist ideology that neglected the realm of tradition. The authors discuss some tyoes of vernacular buildings and their relation to local landscape, especially focusing on the traditional vernacular dwelling of Kuršių nerija (coastal regionbordering with Curonian spit and the Baltic Sea. This region was originally an area of fishermen villages and though some of the settlements ceasedf to exist there are a number of vernacula houses that belong to architectural heritage. The issues of dwellings, authenticity, survival and protection as well as some ambiguous issues of sustainability of traditional dwellings arer discussed. The authors conclude by suggesting that multiple assesment perspective should be employed while dealign with vernacular buildings suggesting that buildings of this type can perform functions extending the tourist consumption.