The contributions in this report jointly describe the ecosystem of the Strait of Georgia, British Columbia, Canada, as it presently is, and as it might have been one hundred years ago, before the massive expansion of commercial fisheries, and five hundred years ago before contact of native Peoples with Europeans. The evidence reviewed includes ecological studies and analyses not only from all of the fish species, but also from all parts of the ecosystem, from whales, seabirds and salmon, to plankton, herring and clams. Essential information on the presence, location and abundance of living organisms is obtained from historical records and documents, linguistic studies, archaeological remains (including petroglyphs and pictographs), and the oral history and traditional environmental knowledge of the Aboriginal people who still live around the Strait of Georgia. This qualitative and quantitative evidence, gathered during a three-month pilot project, was reviewed at a multidisciplinary workshop held in November 1997 at the First Nations House of Learning, U.B.C. The data has been used to construct ECOPATH mass-balance models of the Strait of Georgia for the three time periods. The models comprise 25-27 functional groups. The epistemological, conceptual, and methodological issues raised by this interdisciplinary approach are discussed, as is the suitability of the ECOPATH method to serve as a template for ecosystem reconstruction of this type. The work here represents a pilot phase in developing this new methodology. The `Back to the Future' process includes the model reconstruction of past and present ecosystems as a way of informing policy choices for fisheries. The evaluation of local benefits that may be extracted from alternative ecosystems, the design of practical management instruments, and the monitoring of the recovery of ecosystems and compliance, are all factors that may endow the method with powerful support and consent among a broad range of stakeholders.