Here’s a handy annual fishing calendar for Perth waters …

Garfish – best in winter (a ban was introduced, check before fishing).
Bream – all year, but they swim up the rivers in summer.
Herring – Summer. They bite day and night.
Mackerel – when the water reaches 22C the spanish mackerel may show, usually after Christmas. West End is a good spot. Watch reports up the coast as the fish move south.
Bonito – abundant in summer, autumn. Can be caught land-based at North Mole, Woodman Point and Trigg.
Dhufish – all year, usually found around deeper reefs, but some are caught on shallow reefs and from shore.
flathead – usually run into the Swan River about December.
Mahi mahi – WA’s offshore FADs have small fish in early summer, with bigger fish later.
Mulloway – best in the Swan in early summer. Try Mosmans and the Narrows, and Scarborough and Mandurah beaches.
Pink snapper – fish reefy ground. Snapper restrictions apply in Cockburn Sound. Can be caught from rock groynes during winter storms.
Salmon – autumn and winter.
Samson – from December until March, best in March. Schools of big fish show up. Wrecks are best.
Skippy – winter for bigger fish.
Tailor – all year.
Yellowfin tuna – summer.
Whiting – for large yellowfin whiting, try fishing the Swan River at night at East Fremantle and Claremont.
Squid – try Garden Island, and jetties with night lights.
Crabs – summer and autumn. Mandurah is popular, but before Christmas try deeper parts of the Swan River for bigger crabs.

Here is a list of recommended tackle for WA waters.

Perth tides
Perth stocked waters
Perth dam levels
WA fishing regulations
WA marine parks