We construct a mathematical model describing the spatio-temporal changes in spatial domains of three species in their mutual interactions. This three-trophic population model describes the general problem of food chain composed of prey (phytoplankton), predator (zoo-plankton), and superpredator (fish). Numerical measurements of the spatial correlation function of domain patterns of each species show a dynamic scaling behavior, where the characteristic length L(t) spatial domain increases with time, satisfying the power law of L(t) ∼ t. For the super-predator and the predator, there is a single growth exponent. In contrast for the prey there are two different growth regimes with two exponents.