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The thesis analyses compensations of damages caused by great cormorant (Phalacrocorax carbo) in fish farms in South Bohemian Region pursuant to Act. No 115/2000 Sb. till 2011. In the introductory section is described a development of population of nesting and migrating Great cormorants in Europe, particularly in the Czech Republic from the 80th of last century, and reasons for conflict between this species conservation and fish farming including legal conditions for compensation to pond owners and a development of compensation issues in the Czech Republic. This thesis assesses an overall status of the compensation of damages already paid in South Bohemia, analyses claimants according subject type and compares the amount of compensation of damages in relation to the number and the pond area including the frequency of submitted apllications by different types of claimants and the relationship to individual districts of South Bohemian Region. The survey in five chosen ponds in Třeboňsko region evaluates a current secondary damages caused by Great cormorants in the form of injured fishes obtained during fishing out.

Piscivorous birds are an integrated part of lake and coastline ecosystems. Despite decades of research it is yet unclear what influence fish eating birds have on the fish community. The aim of this literature study was to focus on how two fish eating birds, Great Cormorant and Great Crested Grebe, influence the fish community in shallow and eutrophic lakes. Different types of analysis methods have been used when doing research on the subject, including pellet analysis, stomach content analysis, tagging of fishes by “PIT”-techniques and analysis by observation. Results show that conclusions by studies tend to vary, but generally higher bird density, lower water temperature and a relatively high turbidity contribute to a higher influence on the fish community. Both bird species are opportunistic in their choice of food and catch prey of the species that occur locally. Both species also limit themselves in the prey size, but the choice vary over seasons because of water temperature and the birds requirements in association with breeding and migration. The significant level of influence seems to be when predation is conducted on younger and smaller fishes. The influence on the fish size can also be indirect, where predation on smaller individuals prevent fishes from becoming older and bigger. As studies tend to deviate in conclusion, no general answer to this issue can be given at present. Comprehensive research with several years of full control over both fish-and bird population is needed to find the proper conclusion.

Recreational fishing is a very important leisure activity and one of the most important ways how humans influence freshwater habitats and wild fish populations. Both fish-eating predators and socio-economic trends play a major role in recreational fishing. This thesis found that the Eurasian otter feeds mainly of small (5-10 g) and very abundant fish species of low angling value. In this case, gudgeon Gobio gobio dominated in the otter diet. The overlap between catches of otters and anglers was very low, and commercially important salmonids made up only 10 % of the otter diet by biomass. Cormorants also prey mostly on smaller (10-100 g) a very abundant fish species. In this case, roach Rutilus rutilus dominated in the cormorant diet. The overlap between catches of cormorants and anglers was also quite low. Commercially important fish species made up less than 10 % of the cormorant diet. Even though cormorants consume mostly smaller fish, they are potentially removing fish that serve as prey for piscivores, and they are also removing smaller fish that would grow into angling size. The Atlantic salmon Salmo salar reintroduction programme has not yet been successful. However, cormorant predation is not the main reason for its low success. The main problem is somewhere on the lower River Elbe in...

Noteworthy species endemic to the Galapagos Islands off Ecuador are two flightless birds, the Galapagos Penguin (Spheniscus mendiculus) and Flightless Cormorant (Phalacrocrax harrisi). Both adapted increased swimming ability at the cost of flight. This however has limited their ability to find richer feeding grounds in times of low resource availability, or to escape potential predators. Their population numbers, though small, were stable. Stress on this stability has increased since human arrival. Various invasive species from pets, farm animals and rats to even mosquito vectors of avian disease accompanied humans. . El Nino Southern Oscillation or ENSO cycles of warm waters in the Pacific Ocean south of the Equator cause drastic drops in food sources for all Galapagos seabirds. Serious ENSO events in 1983 and 1998 caused some species’ populations to drop by as much as 77%. Periodic less severe cycles may help explain how population recovery has not rebounded to earlier numbers. Reduced chick survival and adult fecundity seem to occur in concert with mild events. With available data and use of a modeling approach, this study focuses and explores their situations. Restoring population stability may include use of models, species monitoring, conservation and limiting invasive species. Usher matrices based on different climate conditions were produced using data combined from current and past census counts and weather. Models are used to compare available census data and test reliable predictors. Climate data from National Oceanic and Atmospheric Administration and the University of Florida provides for testing predictions of current and probable future climate change. Life histories of both species are regarded. Results suggest the current Cormorant population is still stable. The Penguin, however, faces a 20% probability of extinction in 100 years if current conditions remain. Extinction probability rises to 60% if climate change continues to worsen. Interventions such as captive breeding could be suitable for population recovery.

The thesis was chosen on the basis of the continuation of the bachelor´s work. This thesis is focused on the literature search of problems of the conflicts between the protection of cormorants and the interest of fishery, further on the media analysis in the Czech Republic and finally on the processing of opinions of various groups of respondents (holidaymakers in the area called ´Třeboňsko´ and Czech fishermen). The opinions of questioned people were obtained from controlled interviews written down and processed in the questionnaires. The available information shows that a number of the protected cormorants is increasing not only in the Czech Republic but all over the world. The increase of the number of cormorant population causes problems especially to fishery, because cormorants cause the damage by catching fish stock. These conflicts in the problem area are mostly promoted in the media. In the problem area there are important opinions of the key groups of inhabitants. Groups of questioned people demonstrated their knowledge: holidaymakers in the area called ´Třeboňsko´ have basic knowledge in cormorants and problems caused by cormorants. On the contrary, fishermen are well-informed about the problem. The fishermen are more interested in the problem. Media are very important for solving conflicts and forming opinions of various groups of people. Media analysis showed that most spokesmen, who initiated writing newspaper articles were just fishermen. Therefore the articles on the cormorants are negative and without opinions on the spokesmen as member of general public or academics. Results of the sociological analysis have feed back on the results of the media analysis. It was found out that in the Czech Republic there had not been drawn up any management of fish protection againts cormorants. That is why I prefer to suggest the management in the near future. I recommend to follow the existing foreign management, forexample, in Great Britain. Further, I propose to change the Czech legislation for lower payment of the compensation for the damage caused by cormorants.

vi Abstract Continental subspecies of the great cormorant (Phalacrocorax carbo sinensis) is the Czech Republic's most important fish-eating predator. It causes damage to production fish, as well as sport fishermen and even after its removal from the Czech list of endangered species in 2013, it did not disappear from the spotlight of both local fishermen and researchers. This thesis evaluates the qualitative and quantitative composition of the cormorant's diet during winter 2011/2012 at two selected locations: the Žehuň pond (Kolín district) and Berounka river in the natural reserve Zábělá near Pilsen. This work studies the main components of cormorant's diet in the selected locations and evaluates potential fluctuations and changes in its composition during winter. The study also conducted the analysis of the proportion of commercially harvested valuable fish in cormorant's diet and studied its diversity of the species spectrum. The resulting data for the two sites were compared with each other and with relevant literature. Regurgitated pellets analysis, as well as analysis of diagnostic bones and fish remains located at the sleeping roosts (night roosts) were used for the diet analysis. It was found that at both sites roach was the most caught fish, but from the point of view of total biomass, it was...

Piscivorous birds are often blamed for causing significant damage to fish stocks. Various methods are used to determine the composition of their food, each of them has limits in its ability to determine the complete food spectrum. This work maps the complete food composition of 14 species of fish-eating birds with a method that is not commonly used. Method used in this work uses analysis of publicly available photos on Google.com. In addition to the complete composition of the food, the species composition of the non-fish part of the prey was also determined, and in the case of the Great Cormorant (Phalacrocorax carbo), also the length of the fishes it catches. The aim of this work is to reveal the usability of this method for these purposes. A total of 2350 retrieved photographs were analyzed. The results obtained by photo analysis are in all cases compared with data in the available literature. For representatives of heron birds (Ardeidae), the analysis of photographs provided good information on the food spectrum of individual birds and on the qualitative composition of the non-fish component. It also provided relatively good information on the diet of the White-tailed Eagle (Haliaeetus albicilla), but the bird part of the prey was slightly underestimated. In the diet of the Great Crested Grebe...