As Robyosh mentioned, Island lake has some of the biggest leeries I have seen, unfortunately we try to keep it a bit quiet because of some people almost going commercial on them - killing all they can catch ! And i am not talking about the local indigini , man I must be on the water one day and come across these chaps !!
Anyhoo, I have landed a few good fish on artificials - namely, spook,arc minnows and lipless cranks. There are also some healthy bass in Island lake, so if the leeries are quiet try get some bass. There are lots of other species in this body of water such as carp,steenie,big southern striped mullet,big tilapia and the odd grunter and stumpies.