(Anguilku australis) in the Snowy River System,

Juvenile anguillid eels, known as glass eels, form the basis of important commercialfisheries in many parts of the world. The majority of glass eels are used as seedstock for aquaculture because the artificial propagation of anguillid eels is not yet technologically possible. Several environmental cues are thought to influence both the invasion ofanguillid glass eels into estuaries from the sea, as well as their migration patterns within estuaries. An understanding ofthese environmental correlates may help to determine optimalfishing times to largetpeak glass eel invasion and migrations. in the present study, the invasion of Australian shorfinned glass eels (Anguilla australis) into sourh-eastern Australian estuaries was investigated for the purpose of characterising the primary environmental cues associated with such invasions and migrations. Glass eel assessment surveys were conducted in the Snowy River, south-eastem Australia, as part of a national glass eel assessment programme during rhe winter and spring of 1997 and 1998. Catch per unit effort (CPUE) was used to estimate relative abundance of glass eels. Several variables were examined for possible correlations with glass eel abundance including water temperature, salinity, stream discharge and tidal and lunarphases. CPUE oJglass eels was highly variable between years. However, the results suggest thal the migration of A. australis glass eels occurs during discrete seasonal periods in the Snowy River, and that optimun~fishing times can be identified using a range of environmental criteria including tidal and lunar phase, water temperature, stream discharge and salinity