Ecosystem-based Global Fishing Policy Scenarios
2007 | FCRR 15(7)
The world’s marine fisheries are in trouble, but there are, among fisheries scientists, strong disagreement about the extent of this crisis, if any. One factor which tends to affect the view taken as to the global state of fisheries is the geographic area, and hence the fisheries and management systems, with which people are familiar. Thus, one may expect the fisheries scientists and the marine biologists from areas or countries with well-managed fisheries and healthy ecosystems to assume that global fisheries and ecosystems are in similar states, while those colleagues working in areas where fisheries management doesn’t work, and the stock are overfished, would assume that a similar situation occurs at the global scale.
Such subjective bias can be overcome using two different approaches. The first consists of using a preset ‘sampling scheme’ for the fisheries and ecosystems used for extrapolation to the global scale. The second approach, in contrast, is to use a ‘census’, wherein ‘all’ fisheries and ecosystems of the world are somehow used for global inferences. This approach can be implemented (i) in stratified fashion, using large chunk of the world ocean as strata, and adding up the result to get a global picture, or (ii) working right away on a
global basis. It is the first of these implementation methods which was used here, but the second will follow, as briefly mentioned below.
EcoOcean is the first iteration of a global marine model which addresses many of the past problems associated with assessing the future of fisheries at the global scale. The development of EcoOcean was based on the global fisheries-related datasets made available by the Sea Around Us Project, which, by complementing and standardizing the catch and effort data available from the Food and Agriculture Organization of the United Nations (FAO), makes global analyses of fisheries possible.
The fleet statistics provided a basis to develop a global effort database for the years 1950 to 1998 (the last year for which global data are available from FAO), which provided effort trends that are the primary driver of the model. The development of an integrated global database of fishing effort across all oceans from 1950 to the present was a requirement toward the construction of the global model and is described in detail in this report. This database will be used in other studies where information on global effort is required. Other databases, e.g., for distant water fishing vessels, were also created and used to drive the model, and are described in this report.
The development of EcoOcean was in response to a growing demand for tools to explore the future of fisheries and marine biodiversity. EcoOcean, which is spatially defined by the 19 FAO fishing areas covering the world’s oceans, is driven by the effort of five fleets, with different trajectories in each FAO area. The model output from EcoOcean can be used to describe how biomass, landings, profits and the marine trophic index may change under different policy scenarios in different areas of the world.
EcoOcean provides a common reporting platform so that the outcomes of the different scenarios can be compared within and between geographic areas, as well as for fleets and fisheries.
The application of EcoOcean to explore the scenarios proposed by the Global Environment Outlook 4 (GEO4) and the International Assessment for Agricultural Science, Technology and Development IAASTD) demonstrates the usefulness of this policy tool, while the outputs themselves provide policy makers with plausible results on which to base future decisions regarding management of fisheries and marine ecosystems.
The next step for EcoOcean is obviously, the application of this tool to smaller strata, i.e., the 64 Large Marine Ecosystems which have been defined for the world ocean, and ultimately, to the 180,000 half degree cells into which the Sea Around Us Project has divided this same ocean. This will obviously require the refinement of all databases created by that project, itself a useful venture, for both the project itself, and the wider community with which it shares data.
Director, Fisheries Centre