A discussion is presented on the 2 approaches - holism and reductionism - in the study of environmental sciences, making reference to various projects presently being conducted by ICLARM and its collaborators using the holistic approach. Schematic representations are given of ICLARM's FISHBASE, the ECOPATH II model of the Peruvian upwelling ecosystem and submodels which may be incorporated in large simulation models of the upwelling system, and also material flows in a rice-fish/shrimp integrated farming systems of the Mekong Delta, Vietnam.