Reef & Estuary By-catch in WA: What Is This Fish?

You dropped a bait on the reef for dhufish, or worked a jetty pylon for whiting, and what came up was not in the brochure. Wrong shape, wrong colour, possibly armed. Now you’re holding the rod at arm’s length wondering whether this thing is dinner, bait, or a trip to the emergency department.

This guide covers the by-catch that turns up on WA reefs, jetties and estuaries — the fish nobody targets but everybody eventually catches. For the surf-and-sand version, the companion WA beach by-catch ID guide covers sergeant baker, goatfish and the rest. Some of these are quietly good eating. A couple will sting you. Two are toxic and must never go in the pan. When you’re unsure: photograph it, check the rules, put it back.

Good to eat

Triggerfish

The big mystery catch over reef and around jetties — a deep, oval body, small mouth with a serious beak, and a stout first dorsal spine that locks bolt upright, the “trigger” that names them. The skin is sandpaper-tough, so most people skin them with pliers rather than scale them; underneath is firm, sweet white flesh that’s genuinely good eating. The fish you swore at is a feed. Triggerfish aren’t listed individually in WA’s tables, so they sit in the “all other species” mixed daily bag of 30 with no minimum size. Mind the beak and the locking spine.

Rock ling

Long, eel-tailed and mottled grey-brown, with a jaw that runs well past the eye — rock ling (Genypterus tigerinus) hole up in caves and crevices on shallow reef and grab bottom baits. They look prehistoric, but they’re prized eating with soft, sweet white flesh. Not individually listed in WA, so they fall in the “all other species” bag of 30 with no minimum size. No venom, no drama — just an odd-looking keeper.

Sweetlip

A solid, deep-bodied fish with thick, rubbery lips — the name is literal — grey to silver, sometimes spotted or barred. They show up on reef baits from the lower West Coast north and are good eating at size. WA groups sweetlips together at a 300mm minimum size and a bag of 8 inside the nearshore/estuarine mixed daily bag of 16. Confirm the current rule on DPIRD, because that nearshore bag is shared across many species.

Sea sweep

Dark, deep and oval, sea sweep (Scorpis aequipinnis) hang around rocky reef edges and wash zones along the lower West and South coasts — often alongside herring and the slim, hard-pulling skipjack trevally you’ll pull from the same wash. Good on the plate, with no minimum size but a bag of 4, counting toward the nearshore mixed bag of 16.

Release or use as bait

Yakka (yellowtail scad)

Slim, silvery with a yellow-tinged tail and a dark spot on the gill cover, yakkas school thick around jetty pylons, pontoons and marinas — drop a bait jig with a bit of berley and you’ll fill a bucket. They’re the classic WA jetty live bait: hardy enough to stay lively on a hook, which makes them prime live baits for yellowtail kingfish, samson fish and mulloway. Decent eating bled and iced, but most anglers catch them to fish with, not to fillet. As a baitfish they sit outside the standard bag tables — check DPIRD if you’re unsure how many you can hold.

Western butterfish

A small, slim fish to about 26cm — silver-grey with a dark stripe edged in iridescent blue running snout to tail. Despite the name it’s a threadfin bream (Pentapodus vitta), not a true butterfish, and they pick at baits over sand near reef and seagrass. Edible but small and soft, so most go back. Not individually listed, so they fall in the “all other species” bag of 30 with no minimum size.

Handle with care: venomous or toxic

This is the section that matters. Two of these will sting you; two will poison you if you eat them. Read it before you reach for the fish.

Cobbler

The estuary catfish that ends sessions. Eel-tailed, smooth-skinned, olive to brown, common in the Swan and the Peel-Harvey and a regular on bottom baits set for bream. They look harmless. They are not — cobbler carry venomous spines on the dorsal and pectoral fins, and a sting is excruciating and slow to fade. Never handle one barehanded: pin it with a towel or use long-nose pliers, snip the spines first, and keep kids and dogs well clear. If you’re stung, get the area into water as hot as you can stand and seek medical help if it worsens. Despite all that, cobbler are good eating once skinned — white, firm and boneless. They’re grouped with catfish at a 430mm minimum size (estuary cobbler) and a bag of 8 in the nearshore/estuarine category; the cobbler page has the full ID, with the northern silver cobbler for comparison.

Boxfish

Unmistakable — a rigid, boxy little fish encased in fused bony plates, often pale with dark spots, paddling along on tiny fins. They blunder onto baits over reef and rubble. Do not eat boxfish: when stressed they secrete a skin toxin (pahutoxin, also called ostracitoxin) that has caused serious human poisoning. That same toxin is why you should never drop a stressed boxfish into a bucket or live well with fish you mean to keep — it leaches into the water and can kill the lot. Unhook it in the water if you can and let it go.

Blowfish (pufferfish)

The bait thieves with attitude — round-bodied, big-eyed, with a parrot-like beak that strips a hook in seconds and inflates when annoyed. Blowfish are flatly toxic: they carry tetrodotoxin in the skin, liver, gut and gonads, there’s no safe home preparation, and it has killed people. Never eat a blowfish, full stop. Mind the beak when you unhook one — it bites — and cut the line if the hook won’t come out cleanly. More at the blowfish page.

Shovelnose shark / ray

Part shark, part ray — a flat, shovel-shaped head and disc up front blending into a shark-like body and tail. The WA one (western shovelnose ray) cruises sand near reef and estuary mouths and picks up bottom baits. No venom, harmless to handle, but it falls under the sharks-and-rays category, which carries a combined daily bag of 3 across all sharks and rays. Most anglers release them. If you’re considering keeping one, check the current sharks-and-rays rules on DPIRD first — that combined limit is easy to trip over.

Where the odd ones turn up

By-catch follows structure and bottom type. A few reef, jetty and estuary marks where the surprises show:

  • Busselton Jetty — nearly two kilometres of pylons over sand and seagrass; triggerfish, butterfish, sweetlip and yakka all on the cards.
  • Ammo Jetty — pylons and rubble holding yakka and the odd triggerfish or boxfish over the reefier patches.
  • Woodman Point Jetty — deeper edge over sand and reef, good for yakka schools and reef by-catch.
  • Point Walter — Swan River sand spit and drop-off where cobbler turn up on bream baits.
  • Mandurah Jetty — estuary edge of the Peel-Harvey; cobbler and blowfish are regular bait thieves.

How to ID anything new

Work through it in order:

  1. Body shape — eel-tailed and smooth (cobbler), boxy and rigid (boxfish), round and inflatable (blowfish), deep with a locking spine (triggerfish), shovel-headed (shovelnose ray).
  2. Can it hurt you? — cobbler stings; boxfish and blowfish poison if eaten. When unsure, treat every spine as if it means it and never eat anything you can’t name.
  3. Colour and markings — note them before the fish dulls; stripes, spots and gill-cover marks are often the clincher.
  4. Check the rules — look the species up on DPIRD’s bag and size limits before keeping anything. The only limit that counts is the current one.
  5. When in doubt, release it — gently, into any wash. An unidentified fish put back costs you nothing.

Frequently asked questions

Can you eat triggerfish?
Yes. Triggerfish have firm, sweet white flesh once you get past the tough, leathery skin — most people skin them with pliers rather than scaling. They aren’t listed individually in WA’s tables, so they sit in the “all other species” mixed daily bag of 30 with no minimum size. Mind the locking dorsal spine and the strong beak when you unhook one.

Is a boxfish poisonous?
Yes. Boxfish secrete a skin toxin — pahutoxin, also called ostracitoxin — when stressed, and eating them has caused serious poisoning. Don’t eat boxfish and don’t put a stressed one in a bucket or live well with fish you intend to keep, because the toxin leaches into the water. Unhook it in the water if you can and let it go.

Are western butterfish good to eat?
Western butterfish (Pentapodus vitta) are a small threadfin bream to about 26cm, silver with a dark blue-edged stripe from snout to tail. They’re edible with soft white flesh but small, so most anglers release them. They aren’t listed separately in WA, so they fall in the “all other species” bag of 30 with no minimum size.

What is a yakka used for?
A yakka — yellowtail scad — is mainly used as bait. They’re hardy, so they make excellent live baits for yellowtail kingfish, samson fish and mulloway, and chopped up they make good berley. They’re decent eating bled and iced, but most WA anglers catch them off jetties on bait jigs to fish with, not to fillet.

How do you safely handle a cobbler?
Cobbler have venomous spines on the dorsal and pectoral fins that cause severe, lasting pain. Never grab one barehanded — pin it with a towel or use long-nose pliers, and snip the spines off before handling. Keep kids and dogs clear of one flapping on the deck. A sting needs hot water (as hot as you can stand) and medical attention if it worsens.

Is a blowfish poisonous in WA?
Yes. Blowfish (pufferfish) carry tetrodotoxin in the skin, liver, gut and gonads — there is no safe way to clean one at home and it has killed people. Never eat a blowfish. Cut the line or unhook it carefully and release it; they also have a sharp beak that strips baits and bites fingers.

Still stumped by something on the reef or in the estuary? Photograph it next to a ruler, check the rules, and let the BiteCompass forecast set up your next session — ideally one where you land what you came for.