Blue crab is an invasive species in the Mediterranean and Mediterranean sea. Its population has just begun to increase and expand towards to the central Adriatic. Given that the species is recognized as an opportunistic benthic omnivore that feeds even on carrion, colonization can have a negative impact on local flora and fauna, primarily to reduce algal populations equal to major food sources, but also to reduce populations. native crab populations through competition for food and habitat. Given the large potential broader population of these species and their invasiveness, there is no effect of a radiation measure of this species for the time being. The measures than can be take are the constant catch of the blue river and the use of filters in ships at places of ballast water exchange. Invasive species, such as blue crayfish, spread very quickly, are difficult to catch, and when discovered, are nearly impossible to remove because it is too late. Currently, plaques are crustaceans that have not contributed to the economy of the Republic of Croatia since they are not used for gastronomic purposes or have not been recognized. In order to change, it is necessary to use what is available in the waters of the Republic of Croatia, in order to realize the economic benefit and use the lost natural balances.