The main objective of the D4SCIENCE project is to deploy the e-Infrastructures built so far by the EGEE and DILIGENT projects so that they address the needs of several new scientific communities affiliated with the broad disciplines of Environmental Monitoring and Fishery Resource Management. These e-Infrastructures, which offer mechanisms that concurrently exploit networks, grids, and data in a seamless fashion, will enable scientific communities to operate within a coherent pan-European model, regardless of the location of their research facilities. The D4SCIENCE project will progressively consolidate and expand these open e-Infrastructures to better address the needs of the two major target disciplines (which have challenging differences but also interesting commonalities). Thousands of scientists will obtain increasingly more facilities for creating Virtual Research Environments based on shared computation, storage, and generic service resources offered by EGEE and DILIGENT at a European level, as well as on data and domain-specific service resources offered by large international organizations, such as ESA, FAO, and CGIAR. The envisioned D4Science e-Infrastructure will have a multiplicative benefit to many scientific fields and will also act as a catalyst for the kind of cooperation and cross-fertilization among multiple communities that is necessary for addressing many grand challenges of science and society.