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This report describes the structure and workings of an Ecopath with Ecosim (EwE) ecosystem model for the waters surrounding Haida Gwaii, British Columbia. The model area lies in the southernmost part of the Gulf of Alaska Large Marine Ecosystem, and hence is predominantly boreal in species composition, although with more commonalities with the California Current than are present in more northern waters. The report covers the development and parameters of the static Ecopath food web model from its early antecedents (the Hecate Strait models) through the recent (2000) and historical (1750, 1900, 1950) Northern British Columbia models to its current form and future improvements. The current version of the model contains 78 functional groups spanning five trophic levels (including increased functional group resolution for marine mammals, elasmobranchs and herring age classes and stocks) and 21 fisheries (including commercial, recreational and aboriginal fleets). Future improvements to the Ecopath model include improved representation of Pacific herring (age/size classes, stock structure and diet composition), zooplankton and epifaunal invertebrates. The report also addresses the use of this model as a platform for dynamic simulations in Ecosim (including the vulnerability parameters based on foraging arena theory) and spatial analysis in Ecospace. The latter includes the sources and processes involved in the designation of the base map, habitat capacity and sailing cost maps for functional groups and fisheries, and marine protected areas.

The Gulf of Mexico supports a high biological diversity and biomass of fish, seabirds, and mammals; in this region, multiple commercial and recreational fishing fleets operate providing economic resources for local populations. The Gulf is also the site of important oil and gas production and tourism. As a result of intensive human use, the Gulf is subject to various impacts, including oil spills, habitat degradation, and anoxia. Management of this Large Marine Ecosystem requires an ecosystem-based management approach that provides a holistic approach to resource management. The Gulf of Mexico is managed as part of NOAA's Integrated Ecosystem Assessment Program (IEA). This program considers the development of ecosystem models as a tool for ecosystem-based fisheries management (EBFM) and to support the different stages in the IEA process, particularly testing the effects of alternative management scenarios. As part of this program, we have parametrized an Atlantis ecosystem model for the Gulf of Mexico, including major functional groups, physiographic dynamics, and fishing fleets. The Gulf of Mexico (GOM) Atlantis model represents a collaboration between the University of South Florida, the University of Miami, the Southeast Fisheries Science Center, the National Coastal Data Development Center, and other contributors.

Director's forward. Executive summary. Ecosystem simulation models for the Bird's Head Seascape, Papua, fitted to field data (Cameron Ainsworth, Divya Varkey and Tony Pitcher). The migrant anchovy fishery in Kabui Bay, Raja Ampat, Indonesia: catch, profitability and income distribution (Megan Bailey, Christovel Rotinsulu, and U. Rashid Sumaila).

Innovative methodology is developed for Back to the Future (BTF) restoration policy analysis to aid long-term strategic planning of ecosystem-based restoration in marine ecosystems. Mass-balance and dynamic ecosystem simulation models (Ecopath with Ecosim: EwE) are developed to represent the marine system of northern British Columbia as it appeared in 1750, 1900, 1950 and 2000 AD. Time series statistics are assembled for biomass and catch, incorporating local ecological knowledge (LEK) from community interviews and new estimates of illegal, unreported and unregulated (IUU) fishery catch. The dynamic behaviour of the historic models is fitted to agree with this time series information, when driven by historic catch rates and climate anomalies. Each historic period is evaluated in an optimal policy analysis for its potential to supply sustainable harvest benefits. Harvest benefits are quantified using socioeconomic and ecological indicators, including novel measures such as the Q-90 biodiversity statistic. Candidate goals for restoration are drafted based on these historic ecosystems. A new conceptual goal for ecosystem-based restoration is introduced, the optimal restorable biomass (ORB) that represents an optimized form of the historic ecosystems. It is structured to maximize sustainable harvest benefits, and to achieve a compromise between exploitation and the maintenance of historic abundance and biodiversity. Finally, restoration plans are drafted using a novel addition to Ecosim’s policy search routine, the specific biomass objective function, which determines the pattern of fishing effort required to restore the depleted present-day ecosystem into one resembling a more productive ORB state. Cost-benefit analysis indicates that northern BC ecosystem restoration to an ORB state based on the 1950 ecosystem can deliver a rate of economic return, in terms of increased fisheries yields, that is superior to bank interest. The effect of fleet structure is paramount; reducing bycatch will greatly enhance the effectiveness of the fleet as a restoration tool. Restoration plans that sacrifice immediate fisheries profits tend to restore more biodiversity in a given amount of time, but a convex relationship between profit and biodiversity suggests there is an optimal rate of restoration.