Western Australia's southwest coast is shaped by the Leeuwin Current, a globally unique phenomenon. Every other major eastern boundary current on Earth flows toward the equator and brings cold water. The Leeuwin flows the opposite direction, carrying warm Indonesian Throughflow water south along the WA coast. It's why the Abrolhos Islands have coral reefs at 29°S, far further south than coral should survive, and why Perth's water peaks at 74°F in March rather than January.
The fishing here centres on species found nowhere else. Dhufish, the jewel of WA fishing, is endemic to Western Australia. Baldchin groper at the Abrolhos are endemic. The western rock lobster fishery is Australia's most valuable wild-catch fishery at roughly $500 million annually. And when Leeuwin Current eddies push warm water offshore and create temperature breaks, yellowfin tuna and blue marlin show up beyond the shelf.
Species and Seasons
Dhufish (West Australian dhufish): Found nowhere else on Earth. Year-round on deep reef at 65-330 feet. The premium table fish of WA. Targeted on metro reefs off Perth, around Rottnest Island, and in Abrolhos waters.
Pink snapper: Cockburn Sound hosts a famous winter fishery, closed August 1 through January 31 for spawning protection. Also found off Geraldton and Cervantes.
Samsonfish: Deep reef structure year-round, best in cooler months. Targeted by jigging. Strong fighters with premium eating.
Yellowfin and bigeye tuna: Late summer through autumn (February-May), peaking March. Found offshore of Rottnest Island along temperature breaks where Leeuwin Current eddies create mixing zones.
Blue marlin: Summer through autumn (December-April) in deeper offshore waters beyond the continental shelf.
Western rock lobster: Cervantes, 200 km north of Perth, is the heart of the industry. Recreational potting seasons vary by zone.
Australian herring: Winter peak (June-August). Excellent beach fishing along the south coast. One of WA's most popular recreational species.
Baldchin groper: Endemic to WA, primarily around the Abrolhos Islands and surrounding waters. Found on reef structure.
Diving the Southwest
Rottnest Island is less than an hour from Perth by boat. The Opera House and Shark Cave host grey nurse sharks resting before their night hunts. Temperate reef with kelp forests and subtropical visitors thanks to the Leeuwin Current.
HMAS Swan off Busselton is a 114-meter warship scuttled in 1997 as an artificial reef. The crow's nest sits at just 6 meters, the sand at 32 meters, making it accessible to all experience levels. Encrusted with coral, sponges, and resident fish populations.
Abrolhos Islands, 60 km west of Geraldton, have coral at remarkably high latitude thanks to the Leeuwin Current's warmth. Over 54 shipwrecks including the historic Batavia (1629). Unique mix of cool-water southern and tropical northern species.
Busselton Jetty stretches 1.8 km with 300+ marine species colonizing the pylons. A unique artificial reef ecosystem.
Why SST and Chlorophyll Matter Here
The Leeuwin Current is clearly visible on SST imagery as a warm band along the shelf edge, with a 4-7°F differential across its width. When eddies spin off the current, warm-core rings carry tropical water south while cold-core rings bring nutrients to the surface. These mesoscale features are prime fishing grounds because temperature breaks concentrate pelagic species.
Sporadic coastal upwelling events during summer create cool plumes visible on SST and chlorophyll blooms visible on satellite imagery. Perth Canyon shows increased nutrient concentrations during these events.
For divers, chlorophyll maps to visibility. Clean Leeuwin Current water over the reef means good vis at Rottnest and the Abrolhos. Nearshore productivity or upwelling events mean greener conditions.
Fishing & Diving Calendar
December-February: Summer. Blue marlin offshore. Dhufish year-round. Rock lobster season (varies). Water 70-75°F.
March-May: Autumn peak. Yellowfin tuna peaking (March). Samsonfish strong. Leeuwin Current at its strongest. Water 66-74°F.
June-August: Winter. Pink snapper prime (Cockburn Sound). Australian herring beach fishing. Blue cod equivalent. Water 61-64°F.
September-November: Spring. Water warming. Pink snapper closure. Offshore building. Rock lobster season. Water 63-70°F.
Fishing nearby waters too? West AU - Ningaloo / NW Shelf and Bali / Java Sea are the closest covered regions. See pricing for what a plan covering West AU - Perth / SW costs.