Predators and preys in the maths ocean

Abstract

Around 1925 the Italian biologist and natural historian Umberto D’Ancona became interested in fish populations and problems related to fishing activities in the northern Adriatic Sea. He had observed that between 1915 and 1918 the big reduction in fishing caused by the First World War had altered the natural equilibrium within the fish fauna. This had fostered the spread of sharks, rays and other predatory species over their prey, the fish living on plankton and small invertebrates.