M. Pliftski Institute of Oceanography, GdaJisk University 46 Pilsudskiego Av. 81-378 Gdynia, Poland 2 The Baltic Sea with 366,000 km is only 0. 1% of the world's oceans but nevertheless, unique in many ways. The Baltic Sea is the largest area of brackish water in the world. As a formation of nature, it is a sea that in many ways resembles a lake. This makes its flora and fauna interesting and well adapted to the brackish water environment. The recent stage of biocoenosis composition is influenced by several features. Historically, during the last glaciation, when the Baltic was sometimes a huge marine bay and sometimes a large, freshwater lake, several ecosystems developed and were successively replaced. The flora and fauna composition of those previous biocoenosis was discovered from the geological layers corresponding to the Yoldic Sea, the Ancylus Lake and the Littorina Sea periods. Recently the marine influence has come from the North Sea water inflow, which greatly affects the salinity of the deep water. The freshwater influence comes from the fluvial water which gives the surface layer a lower salinity value. Salinity in the Baltic regions varies greatly - Gulf of Bothnia 2-4%0, the central Baltic proper 7-13%0, the Kattegat 15-300/00 in the surface water and 32- 34%0 in the bottom water, the Skagerrak 20-300/00 in the surface and 32-35%0 in the bottom water.

The "ULLA" series is a new and innovative series of introductory textbooks for postgraduate students in the pharmaceutical sciences. This new series is produced by the ULLA Consortium (European University Consortium for Advanced Pharmaceutical Education and Research). The Consortium is a European academic collaboration in research and teaching of the pharmaceutical sciences that is constantly growing and expanding. Before a drug substance can be tested in man, a set of toxicology studies must be carried out in animals and in vitro to ensure, as far as possible, safety for the test subjects. Toxicity studies involve assessment of acute, repeated dose and chronic toxicities, evaluation of potential effects on vital organs, reproductive and developmental toxicity studies, and carcinogenicity studies. This book covers a limited number of areas of drug toxicity which address the major issues including registration requirements of new drugs and pharmacovigilance. It also provides an overview of the methodology and requirements of pre-clinical safety assessment of new medicines. Mechanisms by which drugs cause toxic effects in living organisms, and problems in the toxicity of specific agents are covered, as are regulatory issues, pharmacovigilence, and clinical toxicology. There is no other textbook at this level dedicated to pharmaceutical toxicology, and this new title in the "ULLA" series fills a definite gap in the market.