Currently, there is considerable overexploitation of our marine fish populations. In addition, harvesting has led to fishing-driven habitat damage and degradation, reducing the habitat's ability to sustain fish populations. These concerns have called for an improved understanding of spatio-temporal dynamics of resource stocks and their respective habitats, as well as their harvesters. In order to optimally solve management strategies that address these issues, we develop a theoretical mathematical model for both a fish stock as well as a habitat resource. Both are modeled using nonlinear, parabolic partial differential equations, where the growth rate of the fishery stock is dependent on the habitat. We consider varying movements and boundary conditions. The objective is to find harvest rates that maximize the discounted yield while minimizing the negative effects of harvesting on the habitat. Optimal harvesting strategies are found numerically.