⚠️

HULL BIOFOULING — What to Look For

Found Something Dodgy? STOP & REPORT Queensland Hull Cleaning Quick Reference — Tropical Focus / GBR Protection
Asian Green Mussel ⚠️ PROHIBITED
Asian Green Mussel
Perna viridis
PROHIBITED - Tropical Threat
  • Bright green shell (young)
  • Brownish-green (older)
  • Big: 80-165mm
  • Major threat to GBR!
Harris Mud Crab ⚠️ PROHIBITED
Harris Mud Crab
Rhithropanopeus harrisii
PROHIBITED - QLD Priority
  • Small (up to 25mm)
  • 3 spines each side
  • White-tipped claws
  • Estuarine/sea chests
Carpet Sea Squirt PROHIBITED
Carpet Sea Squirt
Didemnum vexillum
PROHIBITED - Sea Squirt
  • Creamy/tan like old wax
  • Veiny like varicose veins
  • Leathery, NOT slimy
  • Drips like candle wax
Black-striped False Mussel PROHIBITED
Black-striped False Mussel
Mytilopsis sallei
PROHIBITED - Mussel
  • Small: only 25mm
  • Dark stripes on shell
  • Likes brackish water
  • Check sea chests!
Charru Mussel PROHIBITED
Charru Mussel
Mytella strigata
PROHIBITED - Not in AUS
  • Medium: 22-50mm
  • Variable colours
  • Zigzags or spots
  • Blue-purple interior
Killer Algae PROHIBITED
Killer Algae
Caulerpa taxifolia
PROHIBITED - GBR Risk!
  • Bright green - stands out
  • Feather-shaped fronds
  • Creeping runners
  • Up to 65cm tall
Japanese Kelp Wakame PROHIBITED
Japanese Kelp (Wakame)
Undaria pinnatifida
PROHIBITED - Not in QLD
  • Large brown fronds 1-3m
  • Prominent midrib
  • Wavy/ruffled edges
  • Report any sighting!
Brown Mussel ⚠️ PROHIBITED
Brown Mussel
Perna perna
PROHIBITED - Africa/S. America
  • Dark brown to black shell
  • Up to 90mm (fist-sized)
  • Thick shell, hard to break
  • Dense clumps on hulls
Chinese Mitten Crab PROHIBITED
Chinese Mitten Crab
Eriocheir sinensis
PROHIBITED - Crab
  • Hairy "mittens" on claws
  • White-tipped claws
  • Up to 80mm carapace
  • NOT in Australia
Black Scar Oyster ESTABLISHED
Black Scar Oyster
Magallana bilineata
ESTABLISHED - QLD 2019
  • Small-medium oyster
  • Black scar on inside shell
  • Report new locations!
  • Detected NT & QLD
NZ Green-lipped Mussel WATCH
NZ Green-lipped Mussel
Perna canaliculus
PROHIBITED - Mussel
  • Green lip on edge
  • Brown-green shell
  • MASSIVE: up to 240mm
  • Check NZ vessels
White Colonial Sea Squirt ESTABLISHED
White Colonial Sea Squirt
Didemnum perlucidum
ESTABLISHED - QLD
  • Thin white/cream sheets
  • Semi-transparent
  • Encrusts hard surfaces
  • Report new locations!
Pleated Sea Squirt WATCH
Pleated Sea Squirt
Styela plicata
WATCH - Sea Squirt
  • Ridged like a brain
  • Grey-brown colour
  • Golf ball size: 70mm
  • Sits alone
European Shore Crab WATCH
European Shore Crab
Carcinus maenas
PROHIBITED - Niche Hitchhiker
  • Green shell
  • 5 spines each side of eyes
  • Up to 90mm across
  • Hides in sea chests
Asian Date Mussel PROHIBITED
Asian Date/Bag Mussel
Arcuatula senhousia
PROHIBITED - QLD Priority
  • Small: up to 30mm
  • Thin fragile shell
  • Greenish with zigzags
  • Forms dense mats
Blue Mussel NATIVE
Blue Mussel ✓
Mytilus galloprovincialis
Common - No Report
  • Blue-black shell
  • NOT green
  • Pointy triangle shape
  • Normal QLD fouling
Native Tube Worms NATIVE
Native Tube Worms ✓
Serpulidae
Common - No Report
  • SMALL fan (not 45-60mm)
  • White hard tubes
  • NOT brown leathery tube
  • Normal QLD fouling
Native Sea Squirts NATIVE
Native Sea Squirts ✓
Didemnidae
Compare Carefully!
  • Thin jelly-like mat
  • NOT veiny/waxy
  • Slimy, not leathery
  • If unsure - REPORT IT
MarineStream
PROHIBITED - Stop & Report
WATCH - Report 24hrs
NATIVE - Normal Fouling
📞 Found Something? STOP CLEANING — Call Biosecurity QLD: 13 25 23
Hull Biofouling ID Guide v3.0
Queensland • Print A3 Landscape