Structuring decision-making for ecosystem-based management

Ecosystem-based management (EBM) has been widely accepted as the new paradigm to manage marine ecosystems. Although various efforts have been made to define key components, guidelines, and principles, in support of its implementation, there is still a gap between theory and practice. To implement EBM, managers require a decision-making framework in which the values of constituents, objectives and performance measures are consistent and used to evaluate and choose between alternatives. Structured decision-making (SDM) is a systematic approach that can contribute to develop this framework for EBM. SDM was used for the on-going EBM process on the west coast of Vancouver Island, British Columbia, Canada. This case study provides insights into how SDM can be implemented for EBM, as well as some challenges and opportunities encountered during the process.Structured decision-making Ecosystem-based management Adaptive management Integrated ecosystem assessments Indicators

Combination of emission channeling, photoluminescence and Mossbauer spectroscopy to identify rare earth defect complexes in semiconductors

Implanted radioactive /sup 167/Tm//sup 167/Er and /sup 169/Yb//sup 169/Tm impurities in Si and GaN were studied with emission channeling and photoluminescence spectroscopy. The effect of co-doping with oxygen on the rare earth (RE) lattice sites and their luminescence behavior was investigated. Tm and Yb occupy near-tetrahedral sites in Si and substitutional sites in GaN after room temperature implantation and annealing. O-RE complexes are formed upon co-doping with O resulting in modified luminescence signals. RE impurities remain substitutional in O-doped GaN, but are displaced from tetrahedral sites in O-doped Si. We discuss the feasibility of Mossbauer studies using /sup 151/Eu, /sup 169/Tm and /sup 161/Dy to determine the RE valence state and to identify RE defect complexes. (25 refs)