The paper presents a lithodynamic interpretation of the Polish-Russian morpholog- ical and lithological research project along the marine coastal zone of the Vistula Spit, carried out between July and September 2008. 78.4% of the coastal zone is characterized by a balanced environment, with fractional transport of sediments as bed and suspended load. Deposition was observed in 8.2% of the study area. A dynamic environment with a deficit of bed material, local turbulences and erosive trends were found in 13.2% of the coastal zone. The critical erosive current velocities vary from 16 to 20–26 cm s−1.
Migration of Pipistrellus nathusii (Keyserling and Blasius, 1839) was studied from 1995 to 1998 at the Vistula Split, northern Poland. The direction of bat movements during the night were distinguished by two ultrasound detectors facing in opposite directions and connected into a stereo system. To obtain information about fluctuations in the relative density of bats in the study area, bird nest boxes and bat boxes were checked as well. A combination of the results of these two methods allowed the identification of seasonal movements. Spring migration started at the beginning of May and continued until the end of the month. Autumn migration started in mid-July and lasted until mid-September. The peaks in spring and late summer migrations resulted from longer migration activity during nights.