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Assessing the reliability and utility of citizen science data for monitoring and managing sharks
and rays
Andrew Harvey
Jakarta, March 2018
Overview
• Conservation values and threats
• Importance and challenges of data
• Accuracy and precision of citizen scientist data
• Application to management
Sharks & rays at risk
• 24% Chondricthyans face extinction
• “VU” - IUCN Red List
• FAO global landings peaked in 2003
• Indonesia is a global “hotspot” for species diversity and threat density
Associated values at risk
• Global ecotourism • > USD 400 million
• Indonesia ecotourism • > USD 130 million
• Stated preferences• E.g., manta rays attract >70%
visitors KNP (USAID & Reef Check, 2014)
• Tourism development goals • 20 million by 2018 (+ 100%)
Maintaining values needs data
• Accurate and timely information to:• Manage tourism impacts
• Maintain tourism values
• Requires high resourcing across Indonesia’s expansive oceans
• Low-cost Citizen Scientist data:• Early warning of ecosystem change
• Target research and management resources efficiently
Benchmarking citizen science from historical data
• 10-year dataset submitted to MantaWatch Online
• Isolated replicate reports per location and time
• 3 “levels”• Experts
• Professionals
• Citizen Scientists
• Quantify accuracy and precision
High agreement between citizen scientist and expert data
• Comparison of methods
• Bland Altman test
• n = 3,400
• +/- 1
• Non-significant underestimate at low counts
Power to detect 10% change
• Power analysis (Lehr with measured SD) to determine minimum sample size
• 24 samples per site per unit time to detect 10% change
Case study: KNP
• Isolated long-term records from KNP
• Average encounter rate / year, disaggregated by species
• Long-term trends:• Hawksbill = stable
• Reef manta = increased
• Whitetip = decreased
Management scenario
• Determine thresholds via collaborative process (ex. 10%)
• Routine data from citizen scientists
• Agreed action if thresholds exceeded: • Research
• Management interventions
• Efficient targeting of resources