The mathematical theory of stochastic Volterra-Hamilton systems is used to model cost of terpene production of colonizing soft corals and their highly toxic effects on reef–building corals of the Great Barrier Reef based on recent biological findings of Sammarco, Coll and others. The central question asked is what strategies would enable them to survive soft coral colonization. The model predicts that any factor which reduces soft coral encroachment and direct toxic effects has survival value. Reasoning is based on exact solution of a forward Cauchy problem using Kunita backward calculus and involves the Riemannian sealer curvature of phase space explicitly