An assessment of scale, sampling effort and confidence for maps based on visual and acoustic data in MAREANO
MAREANO has mapped Norwegian waters for ten years, and produced several map series at different scales addressing bathymetry, geology, biology and pollution. There has been an increasing demand to document the confidence of these maps, and to evaluate the effectiveness of the present survey strategy in relation to these map products. One aspect has been to examine whether the future survey strategy should be modified in order to optimise the cost/benefit of the programme and produce the best possible map products. This report provides an overview of current survey strategy and methods; a confidence assessment of selected maps (namely, sediment grain size map, biotopes, vulnerable habitats); an overview and discussion of different sampling strategies with recommendations; and an overview of the user needs in national management and industry. As part of the study, we have attempted to quantify the natural environmental variation of the seabed, and developed a tool for doing this. This work is presented in full in a separate report. The study has provided answers to many of the questions raised at the start of the work, but has raised even more questions that should be adressed, in order to optimise future MAREANO survey and sampling strategy. MAREANO is a unique programme, addressing multiple objectives. Mapping the seabed requires substantial resources, and it is important that the strategy and methods employed are optimal with respects to programme objectives, in order to maximise the cost-benefit ratio. The recommendations for future work which are outlined at the end of this report therefore represent an important part of this report. Further optimisation of the programme will require resources for testing and development.