Fish avoidance behaviour in response to a trawl gear

The main objective of the thesis is an introduction to the problematics of fish avoidance behavior in response to a trawl gear towed by one or two trawlers (motor boats). Avoidance or escape reactions are dependent on many factors and ecological conditions influencing animals´ behaviour therefore it is necessary to refer about fish sensory organs and perception. The content also deals with methods useful for studying fish behaviour in the wild. These are invasive and noninvasive technics and methods like acoustics, video cameras and towed gears (mainly trawls). All of them have become an important tool in recent surveys of marine environment as well as freshwater lakes and reservoires