Greg James

Thorny Passage Marine Park


Thorny Passage Marine Park
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General Marine Park Information

The Thorny Passage Marine Park (~2472km2) encompasses Greenly Island, Rocky Island and the coastal waters surrounding the southern tip of Eyre Peninsula, from just north of Coffin Bay on the west around to Memory Cove on the east. It consists of sheltered bays and tidal flats around the Coffin Bay area, to high energy beaches, rocky cliffs and headlands around the exposed southern edge of Eyre Peninsula.

Extensive reef systems (including some small islands) extend all the way around the marine park, providing many opportunities for fishing, surfing and diving. Squadrons of leafy sea dragons are also part of the marine habitat & the Park is often visited by scuba divers for photographic sessions. Be aware that good 4WD knowledge will be required to access some of the beaches in the Coffin Bay & Lincoln National Parks.

It is also worth mentioning that this stretch of coastline is one of the more exposed sections of South Australia, and conditions can be extremely treacherous. Safety first!


GPS Boundaries*

  • The most north westerly point of the marine park is at point 135񴼓.42擡, 34254.92擲, just west of Point Sir Isaac (the northern most tip of Coffin Bay National Park).
  • The boundary then runs due east to the median high water mark along the shore, at 1352133.25擡, 34254.92擲, near Frenchman Bluff.
  • It runs along the coast at the median high water mark (including all bays and headlands) all the way around the tip of Eyre Peninsula to the eastern edge of the Lincoln National Park, to a point on the coast just a little south of Taylor Island at 1355934.93擡, 345549.28擲.
  • Extending easterly into open water to 136񳆅2.72擡, 345549.28擲 and then southerly to 136񳆅2.72擡, 35񴨤.19擲.
  • Running westerly to 1354226.45擡, 35񴨤.19擲, and then heading northwest parallel to the coast along the seaward limit of the State's coastal waters, bulging out to include Perforated Island, the Whidbey Isles and Four Hummocks.

Also included in the Thorny Passage Marine Park are the State's coastal waters surrounding Greenly Island and Rocky Island.


Fishing Information

The cooler water in this area, along with some nearby upwelling provides a rich environment that supports many types of sealife. Commercial fishing activity is based around abalone, southern rock lobster, pilchards, western king prawns and the considerable number of oyster aquaculture farms at Coffin Bay. Recreationally, whiting, garfish, tommy ruff, salmon (trout), mullet and sweep are all common along the coastline, with snook, trevally, snapper and yellowtail kingfish also readily catchable should you head off the coast in a boat.

*Note: GPS boundaries are approximate positions only. For more detailed information, please refer to the DEH website