Dratów, Krzczeń and Tomaszne lakes are among environmentally valuable reservoirs in Poland and Łęczyńsko-Włodawskie Lakeland. These are shallow eutrophic reservoirs of varied water surface. What they have in common is the fact that they are linked by Wieprz-Krzna Canal. The main aim of the present study was to determine the degree of faunistic similarity between planktonic rorifer assemblages inhabiting these particular lakes. The authors were interested to find out whether linking the lakes with the canal, as well as currently applied water exchange could affect the degree of faunistic similarity occurring between these lakes. Physical and chemi-cal analyses, as well as the studies of planktonic rotifers were carried out in the spring, summer and autumn of 2012 and 2013. They included determining the qualitative composition and the density of planktonic rotifers. The studies resulted in finding 50 species of Rotifera, with mean density ranging from 75 to 855 ind. dm-3. The dominants included the common species of Keratel-la cochlearis, Keratella cochlearis tecta, Keratella quadrata, Polyarthra vulgaris, Kellicottia longispina, Brachionus angularis, Ascomorpha odalis and Synchaeta pectinata. The results re-vealed high faunistic similarity among rotifer assemblages inhabiting a particular lake in different years, and high diversification occurring between the lakes compared in the work. The analyses showed that linking the lakes by Wieprz-Krzna Canal did not significantly affect the faunistic similarity of these particular lakes.

The study addresses the challenges facing the law of the sea. Although UNCLOS is rightly described as a constitution of the law of the sea, it does not and cannot give answers to all problems and doubts that arise in practice and that are related to global warming, protection of biodiversity, legal status of genetic resources, controversy concerning shipping, delimitation of areas or the protection of underwater cultural heritage. Hence the question arises, what the ways and means of further development of the law of the sea are. Undoubtedly, one of the possibilities is to develop implementation agreements, of which the third devoted to the protection and sustainable use of marine biodiversity outside national jurisdiction is the subject of an international conference convened by the General Assembly, whose resolutions in the area of the law of the sea play an important role. Undoubtedly, also the importance of the organization of the United Nations system, such as the IMO, FAO, UNESCO, UNEP is significant. There is also the possibility of accepting agreements addressing the issues left by UNCLOS without solution or definition. Not without significance is the soft law and the practice of states as well as the position of the organs appointed by UNCLOS.