It looks like another strong la nina event this year and that helps. You might want to go read up on it, wikipedia lists a little about it and what years it has been active.

A `big healthy man, with a brown face, big forehead and curly hair’, Sir Garrick swam regularly throughout his life to keep fit. He was an outstanding big game fisherman, taking his cruiser every year from Fremantle to North Queensland in pursuit of marlin. In 1983 at Rottnest Trench he set a Western Australian record when he caught a 319-kg Pacific Blue Marlin.

this is from a article about Sir Garrick Agnew , a businessman ( among other things), from perth, so marlin off perth

isnt excactly new, but I wll agree more and more northern species seem to be expanding there range.

or is just more reported and more people fishing?

giant herring in the swan, northern reefies off rotto, mackies off busso, its all been reported before, ie 1950s , 1960s

if you can find the old articles or speak to some old fossils, hehe

bom site has good info on la nina, going back along time, with all the strong years highlighted and if I

can I like to look at past catches and see if it relates

if often does!