Enhancing expert elicitation techniques through participatory mapping: Application to marine environment assessments in Palawan, Philippines

State of the Marine Environment (SoME) reporting provides an effective mechanism for countries to collate available evidence to highlight pressures and identify indicators of current and changing conditions in marine environments. Expert elicitation (EE) (or expert knowledge elicitation) techniques have been used to ensure a consultative and comprehensive process for achieving these broad seascape assessments, especially in data-poor environments. EE is a consensus methodology that draws on the collective wisdom of known field experts to assist in filling data and knowledge gaps to inform policy decision-making in the absence of other supporting evidence. To date, EE methods for SoME reporting have been limited in their ability to capture and represent data on spatially variable phenomena. The absence of geographic information instils biases and inaccuracies in EE data by aggregating experts' contributions to broad spatial scales, limiting their usefulness in formulating spatially targeted policies operative at scales appropriate for the phenomena of interest. In this paper, a participatory mapping methodology to enhance EE data and processes through inclusion of spatially explicit contributions from experts is described. Paper-based participatory mapping was introduced into an EE workshop for SoME assessment of the archipelagic province of Palawan, Philippines. Analysis of the participatory mapping method was based on observations of the workshop activities in practice, participant feedback, and the authors' appraisal and analysis of the spatial information provided. Integrating participatory mapping within EE techniques enables the representation of expert knowledge and perspectives in a geographic context. In mapping localised pressures and identifying spatial trends expressed in the condition scores across different assessment parameters, participatory mapping can facilitate prioritising locations for further ground-truthing, finer-scale scientific investigation, and conservation effort. An integrated participatory mapping approach has the potential to extend the outcomes of marine environment assessments and better reflect place-based issues within SoME reporting.