Review of Migration Triggers 7
Discharge, water level and current 7
Mekong River 8
Other tropical rivers 9
Precipitation 10
Mekong River 10
Other tropical rivers 10
Lunar cycle 11
Mekong River 11
Other tropical rivers 12
Other migration triggers 13
Apparition of insects 13
Water colour and turbidity 13
Temperature and photoperiod 13
Issues raised by the literature review 14
Importance of fish density as a complementary biological trigger 14
Importance of spawning triggers in addition to migration triggers 14
Multiplicity of triggers 15