The book is devoted to one of the most pressing problems of modern world fisheries - the reduction of fisheries in traditional areas, and in this regard - the conservation of Jurassic bioresources. The monograph contains information about the historical development of the theory of rational fishing, the current state of some of its sections, including the theory of selective fishing. Particular attention is paid to methods for determining the selective properties of fishing gear, in particular net shells with a square structure. Data on the selectivity of pollock, cod and other bottom fish, obtained by the author as a result of expeditionary studies in the North-Western Pacific Ocean (NWTO) are given . A significant amount is occupied by the issues of rational exploitation of Antarctic bioresources. Thus, the analysis of krill fishing is given and recommendations for its improvement are given.. In the final chapter, the author notes, which is one of the ways of rational exploitation of biological resources of the World Ocean , and especially traditional fishing areas, It can be certified as a marine fishery ,. based on the principles of the Marine Stewardship Council (MSC) - an independent non-profit international organization , considers its activities and the possibility of creating such an organization in Russia. The material presented in the monograph is of interest both for specialists in the fishing industry and for students studying in fisheries universities .