Samson Fish WA: The Rottnest Jigging Guide

Samson fish (Seriola hippos) are a large pelagic predator endemic to southern Australia, and a close cousin of the kingfish. Commonly 5–15kg, the Rottnest deepwater fishery produces fish well over 25kg, and they top out past 50kg. One tagged fish went from 7.3kg to roughly 25kg in six years — they grow fast and they grow big.

The identification trap is the rest of the family. Three lookalike Seriola sit in WA’s large pelagic finfish group:

• Samson fish — deep-bodied, blunt-headed, broad-shouldered. The bruiser.
• Yellowtail kingfish (Seriola lalandi) — sleeker, with a clear yellow tail and a yellow stripe running down the flank.
• Amberjack (Seriola dumerili) — similar build to samson but typically caught in deeper, warmer water.

If you can’t tell which one is on the deck, it barely matters for the rules — all three share the same minimum size and the same combined bag limit. It matters a lot for bragging rights, so learn the difference.

The samson fish story in WA is really the Rottnest story. The biggest known aggregations of samsons anywhere gather around deepwater structure off Rottnest during their spawning run, and at their peak — roughly November to February — they stack up in their thousands. This is a boat-based, deep-water fishery: anglers jig metal lures in 100m of water and occasionally deeper, and it once drew jigging fanatics from across the globe.

It is also overwhelmingly a catch-and-release fishery. Samsons release well when handled correctly, the bigger ones aren’t reliable eating, and there’s no point killing a 30kg fish you can’t legally keep three of anyway.

• Rottnest Island — the deepwater marks off the island are the engine room of the WA samson fishery. Boat access only for the proper jigging grounds; check the conditions before committing to the run across.
• Two Rocks Marina and Ocean Reef Marina — northern launch points for boats working the deeper reef lines off the metro coast.
• Hillarys Boat Harbour — a central metro launch for trailer boats heading out to structure.

Smaller samsons turn up on shallower reef and around heavy structure, which brings the shore angler into it — barely.

Land-based samson fish in Perth are rare, and the ones you do hook usually end with a straightened hook or a frayed leader wrapped around something you’ll never see. The deep-water rock walls and pylons are where it occasionally happens.

• North Mole — the deeper water off the Fremantle moles holds the odd samson, usually as a heartbreak by-catch for someone targeting something more reasonable.
• Fremantle Fishing Boat Harbour — structure and current where a live bait fished hard on the bottom can occasionally find one.

If you’re fishing the shore for sambos, fish for them on purpose with gear that’s far too heavy for everything else around, or accept that the hookup is a bonus and the result is a story about the one that took your jig and your dignity.

Samson fish sit in WA’s large pelagic finfish category, which has a combined daily bag limit of 3 fish per fisher — that single limit of 3 is shared across the whole group, so two samsons and a Spanish mackerel is your lot. The minimum legal size is 600mm. Amberjack and yellowtail kingfish carry the same 600mm minimum and draw from the same bag of 3.

Boat fishing in WA also requires a Recreational Fishing from Boat Licence, and since the real samson fishery is boat-based, that one applies to almost everyone chasing them properly. Limits and licence rules change — confirm the current numbers in the DPIRD recreational fishing rules before you head out.

Samson fish destroy under-gunned tackle, so the deepwater jigging rigs are deliberately brutal.

The spawning aggregations off Rottnest peak November to February, which is the window most jigging trips target. Outside that, samsons are around year-round on deeper structure but in nothing like the same numbers.

Fish the tide changes early or late in the day, and lean into the period around the new moon — that’s when the deep-water bite reliably switches on. Before you book a charter or fuel the boat, check swell, wind and tide for Rottnest Island on BiteCompass; the run across exposed water decides whether the day happens at all.