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

Thank you

mantawatch.com

Project Team:

Andrew HarveyTri Nur SujatmikoVidlia Rosady

Project Partners: