Future of Asian horseshoe crab conservation under explicit baseline gaps: A global perspective

Horseshoe crabs are currently threatened by escalating human stresses along the Indo-Pacific coastline. Conservation of their remaining populations, however, is hindered by limited baselines throughout their ranges. We performed a questionnaire survey of conservation experts from diverse geographic regions to identify baselines, prominent threats, impediments and alternative strategies that prioritize Asian horseshoe crab conservation. Despite long-term monitoring across habitat types is lacking, local population declines were widely perceived. Ongoing residential/commercial development along the coast was regarded as the most serious threat. A combination of top-down institutional management and bottom-up stakeholder participation was cited as the most promising strategy. Population and habitat baseline collections should be prioritized in future research to inform conservation planning. In this paper, we summarize the survey findings into the BTPAE (Baseline, Threat, Purpose, Action and Evaluation) framework, which constitutes to our best hope for the future of Asian horseshoe crab conservation.