Adventure among the atolls – Mackerel Islands

Overlooking the boat moorings on Thevenard Island

by Troy Honey •

The beautiful Mackerel Islands, located a short 22km off the spectacular Pilbara coast of Western Australia, comprise of 10 island atolls. Two of these islands, Thevenard and Direction, provide both accommodation and the perfect base for the fishing adventurer. Other prominent islands include Rosily, Tortoise, Ashburton, Surrurier (Long Island as known to the locals) and Ailie.

      The islands of Thevenard and Direction are easily accessed from the town of Onslow, which has a well-protected boat ramp. Facilities at the islands provide mooring only, with loading and unloading the boat partaken on the beach. But a word of warning, it can be quite breezy at times with little protection, so unloading and loading the boat can become challenging. I would recommendation taking your own inflatable tender and a few strong mates to assist with the task.

Troy Honey rock cod
Troy Honey rankin cod
Tim Maciaszek Spanish mackerel
Tim Maciaszek coral trout
Tim Maciaszek cobia
Reuben Bufton red emperor
Reuben Bufton coral trout caught while spear fishing the shallows of Thevenard Island
Michelle Maciaszek Spanish mackerel
Michelle Maciaszek red emperor
Michelle Maciaszek rankin cod
Michelle Maciaszek golden trevally
Jake Maciaszek saddletail snapper
Jake Maciaszek Spanish mackerel
Dylan Biluta tomato rock cod
Beach Fishing Thevenard Island

      Once you are all set up, the variety of fishing opportunities are endless. The range of species, both land and boat based, truly is an angler’s dream. If you are staying on either of the islands with accommodation, one of the advantages is being able to choose the best fishing option to match the day’s weather. You certainly don’t need to miss out on any fishing time if the wind blows up, which it can at anytime of the year, by simply leaving the boat on the moorings and fishing for some of the vast array of land-based species on whichever side of the island offers the most protection.

      Thevenard Island land-based fishing offers species such as trevally, queenfish, flathead, whiting, longtoms, longtail tuna, mackerel, coral trout, Spanish flag, bluebone, spangled emperor and various cod.

      You can fish from the jetty on Thevenard Island where there are always plenty of squid and the chance to catch a mangrove jack. Working the pylons for the latter with bait or lures, such as minnows and jelly prawns works well. Fishing the nights for squid will produce the best results.

      You can walk around the entire island of Thevenard and cast your line. Various sections includes both sandy flats and shallow reefs, and if you work the two different types of bottom with the appropriate rigs on the tide changes you will certainly see some action. The sand flats and weed beds are best for whiting and flathead with the balance of species found over for the reefs.

      Popping for GTs and queenfish is a fantastic way to get into to some pelagics. They can both often be seen busting up on baitfish on the tide changes. The way to target these species is to walk around the islands until you see the surface action, then concentrate your casting in these area.

      If you prefer to chase some tasty seafood then work the reef structures with bibbed minnows, soft plastics or small stick baits. Use bright colours such as green, orange or pink seem to attract the coral trout, spangled emperor, Spanish flag, bluebone and, if you are lucky enough, the ultimate prize of a yellow edged coronation trout.

      Flyfishing from any of the Mackerel Islands has become immensely popular amongst those chasing the prized trophy fish, permit. The flats surrounding the islands offers the perfect environment for sight casting on those clear and windless days into the turquoise north west waters and, as mentioned previously, using the island as a wind break. Fishing on the opposite side to the oncoming wind is a great trick to finding clear water. Permit like to feed in the gully’s close to the shoreline on a rising tide. Always keep watch a few metres in when searching for permit as they can often be overlooked.


      The Mackerel Islands, as their name suggests, is home to various mackerel species such as Spanish, spotted, grey, shark and school mackerel. Many fishers come here just for the chance to land some exceptional examples of mighty Spanish mackerel that are not only in good numbers, but also of enormous size.

      In late August 2020, the annual Ashburton Anglers Mack 10 Fishing Competition was held, which saw 70 boats present 129 Spanish mackerel with the heaviest weighing in at 29.56kg. Many of the fish were well over the 10kg mark, which unquestionably shows just how good this mackerel fishery is!

      Working any of the reefs and ledges around the islands and atolls, with the most popular being Rosily Cay, is where you find the Spaniards. Fishing 5-25m depths is recommended with any number of large minnow style lures working well. If you have a good spread of rods, try using different colours and diving depths until you find what is working best on that day. Sunny or overcast conditions play a big part in colour choice, with my preferred option of bright or shiny colours on sunny days and the old faithful red and white on the overcast days. If you are not gaining any hook ups it is time to try different trolling speeds. Start off in the 5-7 knot ranges, and work up to 8-12 knots if you are not seeing any strikes. Often you will have Spaniards following your lures, but it is the speed that is putting them off. Imposing a bit more speed into the troll is generally all it takes to induce a strike.


      While out trolling, especially if you are geared up with some teasers and outriggers but not needed in most cases, then you cannot go past the opportunity to get stuck into the billfish action around the Mackerel Islands. Sailfish are the more prominent species over the marlin, but both can be found in good numbers.

      On one morning on our recent trip we were punching out at around 14 knots to the 70m mark off Thevenard in moderate seas when we noticed a large marlin following the boat, and that was without any gear in the water at all.

      Black marlin are usually found in waters from 20-70m, along with the sailfish. The much larger blue marlin are found in the deeper waters further out over trenches and gas pipelines in depths of 50-100m and beyond.

      At least one of the three species can be fished no matter what time you visit the Mackerel Islands – there is always billfish action to be enjoyed. Blue marlin season is October to May, back marlin are a year-round occurrence, as are the sailfish, but sailfish are more prevalent from June to November. Always keep an eye out for baitfish and feeding birds as this is the area to concentrate for both billfish and pelagics alike.


      While still on the subject of pelagics we can’t go past the amazing mahimahi that are found in abundance in the clear waters of the Mackerel Islands. Mahimahi, or dolphin fish as they are more commonly referred to, can be fished year-round in these waters with no set high or low season.

      They are encountered when trolled for billfish or pelagics as well as when drifting for demersals where they will often start circling the boat in search of a quick feed. It is here where small stick baits or soft plastics can be cast at the excited mahimahi and retrieved at speed in order to entice a strike. If they are in feeding mode it is only a matter of moments before someone is hooked up. This is the moment for your fishing mates to keep casting, especially next to the mahimahi that is already hooked as they will be hot on his heels for a taste of whatever he has taken.

      Mahimahi are a visually stunning fish, they make for the perfect fishing holiday photo and, combined with superb eating qualities, they are a welcomed addition to any fisher’s day out.


      With the abundance of island and atoll reef systems, gas pipelines and deep-water ledges and bommies, the warm Mackerel Islands waters are a demersal fisher’s paradise. The species list is far too extensive to list them all but it is here you will find all of the most sort after fish, such as coral trout, red, spangled, blueline, longnose, red throat and yellowtail emperors, bluebone, coronation trout, chinaman, saddletail, darktail, rosy and gold band snapper, rankin cod, tomato, blackspotted, goldspotted and greasy rockcod, Spanish flag as well as endless variations of smaller snappers, emperors and cods. It truly is a heavenly place to demersal fish.

      As with fishing for demersals elsewhere, the Mackerel Islands are no different with any form of structure, be it ledges, reefs or bommies, as well as thick sea grass all offering the best place to start. Being in the north west shelf of WA where oil and gas are extract from offshore rigs, the pipelines leading to the Onslow stations from the rigs also provide the perfect structure to attract the many species of demersals. These pipelines are marked on you sounder maps and easily found when motoring with your sonar over them. The accommodation providers will give you some spots to get you started but these are regularly fished, so it is recommended to spend some time on your maps looking for areas to search for your own ground with the possibility of finding areas fished less.


      By far your biggest challenge will not be finding the demersals but escaping the dreaded sharks that plague these waters in huge numbers, especially in the warmer months where they are much more active. Changing spots frequently and fishing with jigs are two recommendations to adopt straight up. If the sharks really become problematic, upping you fishing gear size enabling you to surface your fish at a faster rate is another option. Some days they simply become too much and these days it is best to switch over to trolling for pelagics and billfish or heading back for some land-based action on the islands. You can even snorkel for crays on any of the shallow reefs, which you wont regret with the abundance of them. Do not forget that these waters encounter irukandji from November through to May so best to remember the stinger suit if diving during these times.

      During our trip in late August this year we managed to get amongst some fantastic demersals with both jigs and baits working well. In most instances it did not really matter what we dropped at them along as we had fish on the sounder. The sharks were our biggest challenge, so we concentrated on continuously moving over trying to beat them to the top. Using this method, we lost far less fish and did our bit for the populations of these sought-after fish. We found the goldband snapper and rankin cod to be the best on the plate and there was never a night where we did not get to enjoy the offering of this majestic part of Australia.

      When you throw in the endless whales breaching, turtles, sea snakes, dolphins, bird and reptile life we encountered over our stay it really made the way for that perfect mid-year trip escaping the cold weather to the south of the state. While the Mackerel Islands are a big trip for most, it is one that I highly recommend you tick off your bucket list at least once in your fishing lifetime.