Biodiversity of the Bulgarian-Romanian Section of the Lower Danube

The Danube River is the second longest river in Europe; it flows through ten countries and is 2,850 km in length. In its lower stretches it passes through large lowlands and remains an almost intact natural ecosystem. For 470 km, the river acts as a border between Bulgaria and Romania and provides a refuge for very rich, yet insufficiently studied, biodiversity. The flora and fauna of this area, not far from the Danube Delta biosphere reserve, and its environmental importance are the topics of this book. The book is comprised of 12 separate scientific articles (chapters) that each contain specialized information about key organism groups forming the typical Lower Danube ecosystem. Vertebrate fauna of the study region includes 392 species out of which 83 species are fishes, 19 are amphibians, 15 are reptiles, 201 are birds, and 74 are mammals. Birds are presented in three separate articles with a focus on heron colonies, water birds in the marshlands, and diurnal raptors. Among the invertebrates, several key groups which are comparatively well-studied, are presented, including mollusks; dragonflies and damselflies (in overall 52 species); dipterans of suborder Nematocera (153 species); mayflies (52 species); stoneflies (3 species); and caddisflies (49 species), butterflies (153 species). An article about habitats and typical plants of the Danube plain is also included. The articles all contain information on the status, distribution and ecology of the study's organism groups, and the threats they face. Overall numbers and population trends of some of the presented taxa are also included; 281 maps, 29 graphs, 21 tables and 49 photographs help illustrate various aspects of the collected data. The authors of the articles are well-known and experienced experts on specific organism groups, working mainly out of two institutions of the Bulgarian Academy of Sciences: the National History Museum (Sofia) and the Institute of Biodiversity and Ecosystem Research (Sofia).