A man has always been concerned with monitoring of the quantity of different species of animals since time immemorial. Even prehistoric hunters probably knew about the gathering and distant migrations of aquatic Birds. Great attention has recently been paid to the population trend of fish – eating birds, their changes in quantity and their distribution areas. Obtaining of all data on aquatic birds has a long history and largely depends on the collection of data from the International Waterbirds Census ( IWC ), the collecting was realized over the past five decades thanks to the efforts of thousands of experts and volunteers around the world, and it is coordinated by Wetlands International. In this search I try to summarize findings and the results of several years observations of experts from around the world, especially after the population changes of fish – eating birds in Europe and the Czech Republic, the predation pressure on fish communities have recently enjoyed considerable popularity discussion. A separate task after the identifikation of sites the Carlsbad region with the threat of predation by fisg-eating birds and looks back at the results of the International Waterbirds Census in the yers 2011-2012 in this area.