Although the Antarctic has avoided the worst effects of alien species, its future seems endangered due to increasing natural and man-made pressures. Rapid changes in three major environmental variables have occurred in the Antarctic region during the last decades. In the short term terrestrial biota are likely to benefit from reduced environmental stresses, but in the long run the colonization of the region by lower latitude species with greater competitive ability will become increasingly important and can lead to large-scale changes in biological composition and trophic complexity in some existing Antarctic terrestrial ecosystems. Moreover, the recent dynamic climate changes combined with human activities in the Antarctic region might modify the status of several alien species which have hitherto been considered transient or persistent and could, therefore, become naturalized and threaten the native communities on a larger scale than today, or influence the status of naturalized species.

During three austral summer seasons cargo, expeditioner clothes and equipment of the Polish Antarctic Expedition were examined for the presence of alien propagules. Detailed inspections were undertaken at the station buildings, searching for any invertebrates. During each austral summer fresh fruits and vegetables were also inspected. A total of 359 invertebrates and their remains were found in cargo transported to Arctowski Station, or caught in the station’s facilities. The majority of samples were classified as cultivation pests (26%), food pests (43%), wood−destroying pests (4%), domestic insects and arachnids (15%). Through supply of the research station a wide range of alien organisms can be accidentally transported and ultimately introduced to the Antarctic. This study has clearly demonstrated that almost all cargo items can be a potential vector for alien organisms. Species from a broad range of biological groups can be transported to the Antarctic and remain in a viable state.

Although Svalbard archipelago is considered as a natural laboratory for the environmental studies in the High Arctic, the knowledge on the transport and diversity of bioaerosols (aeroplankton) in the atmosphere is poorly recognized. To improve our knowledge about the aeroplankton over the Svalbard, we conducted a short-term study in the central part of the archipelago with a special focus on two important, but understudied in this region, airborne components: pollen grains and invertebrates. Aerobiological traps, three impact-type samplers and 12 pitfall-type water traps, were operated for a week of July 2022 at three sites located near Longyearbyen, the largest settlement of Svalbard. These sites, that is, Platåfjellet, Longyearbreen Glacier, and glacier valley, varied in the local sources of biological material and altitude. In total, 11 pollen taxa were isolated from pollen impactors. Most of them (68%) belonged to non-native plants, for example, Alnus sp., Betula sp., Picea abies, or Pinus sylvestris-type pollen. In pitfall-type water traps, we found invertebrates representing Acari (Prostigmata, Endeostigmata and Oribatida), Collembola ( Agrenia bidenticulata), Tardigrada (Eutardigrada) and Rotifera (Bdelloidea). The most taxa-rich site, both for pollen and invertebrates, was Platåfjellet, characterized by open landscape dominated by small cryptogams, mainly lichens and mosses, and sparse patches of vascular plants. Even though our sampling was short-term, we found diverse taxa belonged to native and alien species, indicating that both local and long-range transport shape aeroplankton composition and seeding of Arctic habitats. Long-term aerobiological monitoring in diverse ecosystems of Svalbard is needed to understand spatio-temporal influence of aeroplankton on ecosystems.

Round goby (Neogobius melanostomus (Pallas, 1814)) is an invasive species in the Oder River. In this study, age of 147 fish was determined using scales and otoliths, and the Fraser-Lee back-calculation method was used for population structure and theoretical length growth rates with 3 mathematical models of growth: von Bertalanffy, Ford–Walford and 2nd degree polynomial. Fish condition was determined using Fulton, Le Cren and Clark equations. Average total length and weight of fish was 162.00 mm and 83.00 g, respectively. Males were more abundant than females, representing 70% of the fish caught, and achieved greater total lengths and weights. Age 2+ dominated females and 3+ males age groups. Of the three mathematical models used to estimate fish growth, the 2nd degree polynomial model had the best fit to back-calculated lengths. Males had slightly higher growth rates than females in the first two years of life but comparable in subsequent years. The diet consisted of various benthic organisms that varied with fish age. The most frequently occurring food com-ponent was Dreissena polymorpha, which accounted for approximately 70% in the diet of fish with a body length greater than 191 mm.