D A Friess1, S Y Lee2, J H Primavera3. 1. Department of Geography, National University of Singapore, 1 Arts Link, 117570, Singapore. Electronic address: dan.friess@nus.edu.sg. 2. Australian Rivers Institute and School of Environment, Griffith University, Southport, Qld 4222, Australia. Electronic address: joe.lee@griffith.edu.au. 3. Conservation Programmes, Zoological Society of London-Philippines, 43-E Burgos Street, Barangay Magdalo, La Paz, 5000 Iloilo City, Philippines. Electronic address: jurgenne.primavera@zsl.org.