Going after Southern Bluefin Tuna can be both the most rewarding and frustrating experience. Landing a Southern Bluefin Tuna is no easy feet - these species are one of the fastest and largest pelagic fish in the ocean and can get up to a whopping 100kgs. The largest Bluefin Tuna on record was actually caught just off Coffs Harbour at a whopping 217kgs!
Spearing a Southern Bluefin Tuna requires preparation, time, hard work, and unless you're a total cowboy - teamwork! Below is a guide to prepare you for hunting Southern Bluefin Tuna this season.
Step 1. Gear Setup
Bluefin tuna is a large, fast-swimming pelagic fish that can get up to a whopping 100kgs. Having the correct gear to take on this mammoth species is essential! Check out our in-depth gear list here.
We recommend the following gear for hunting Bluefin Tuna:
- An inverted or double roller 110cm - 130cm
- Or a Bluewater Timber Gun (8.5mm shaft + 4 x 16mm Powerbands)
- At a minimum an 8mm shaft.
- A double flopper or slip tip spearhead to increase holding ability.
- One or two high-pressure floats connect in a series of PVC or Spectra float, with a bungee option.
- A good two-piece 5mm open cell wetsuit.
Step 2. Boat setup
Make sure your boat is adequately equipped for offshore fishing, as Tuna is most often encountered past the continental shelf.
Top-notch safety equipment is a must:
- First Aid Kit
- Marine Radio
Make sure to obtain plenty of pilchards for burley - we recommend a 10kg box at a minimum.
Step 3. Choosing the right time and tools.
Wait for the right conditions and the fish - Bluefin Tuna tend to show up at different times each year - social media is an invaluable tool to help you get an idea of when the fish are within range.
We recommend pages like Trapman Bermagui or commercial fishing pages that always report on when the Tuna start showing up.
Apps like Ripcharts will give you an edge when trying to locate the exact position of the fish once you know they are in the area.
The key is to look for temperature change lines, as the bait and tuna will often be close to these pressure points.
Lastly, make sure you have an excuse or two ready for the boss so you can hit the water with short notice, the fish may only stay in the area for a day or two.
Step 4. Finding Bluefin Tuna
On your way out to chase Bluefin Tuna, it's a good idea to stop and catch live bait if your boat is capable of keeping them alive. Where dead pilchards may fail, live bait can be thrown and sound fish that may be 60m - 100m, triggering a feeding frenzy.
Turn your radio on and have it loud enough that you can clearly hear any chatter coming through. Keep a marker pen handy and be ready-to-write down coordinates as they come through.
Other fishermen will often share the marks of fish as the extra burley in the water will keep the fish in the area longer. You may only get one shot at writing down the coordinates so make sure you are ready. Once the other boat is all hooked up they likely won't get back on the radio until the fish are gone.
**If you are approaching fishing boats with Tuna at the surface do not jump in on top of them. Jump in away from the action and start burlying - the fish will come to you. The bigger fish are often found wide or below the main school of fish.
Once you have made it to the fishing grounds the most common method to cover ground is to drag trolling skirts. These can be hookless if you are not interested in catching tuna on a line but they are extremely necessary for raising fish to the surface.
If you mark fish on the sounder or see fish hitting the surface start throwing burley over the side. Now is also a good time to slide into the water whilst someone on the boat keeps feeding burley over the side.
We also recommend carrying a waist catch bag so we can carry our own burley. If you do find a good patch of fish that are staying in the area, give a call out on the radio to help out fellow fisherman.
Keep an eye out for seabirds and other marine life as they will often be in the vicinity of the baitfish and tuna schools. The tide change is a great time to catch tuna at the surface so make sure you persevere until the tide change.
Step 5. Diving and shooting the fish
Before you jump in, have a game plan with your dive buddy or team, the last thing you want to do is to jump in on a school of tuna and rush the shot because you want to get in before your dive buddy. This will likely result in misses and the fish spooking.
The key here is getting a hold of your composure. If it's your first time in the water with Tuna your heart rate is going to be going nuts. The fish can sense this and will likely keep a wide berth until you have calmed down.
Make sure your gear is clear and that your float line is not tangled or hooked up with the boat, and check safety is off. Take some deep breaths and try to focus on your presence in the water, don't dive directly on the tuna.
It's a great idea now to start feeding out some burley from your waist bag, if the fish are feeding, allow them to eat the burley while you take some slow dives to their level and just interact with the school calmly.
Now that you have calmed down, drop into the burley trail and wait and focus on a whole pilchard while keeping an eye on the tuna, ready to take the shot when the tuna takes the bait. Remember to give the fish some lead, these fish are going faster than you think and you are probably using a heavier shaft than usual.
Take the shot.
When it comes to fighting the fish - take your time and stay clear of the rig line. These fish are very powerful and can easily pull a tangled diver underwater. Bluefin Tuna have incredible stamina but lack the explosiveness of a Dog Tooth Tuna. It's best to take your time with the fight you don't want to be dealing with a green fish that is this powerful, you also aren't rushing to beat the sharks like when chasing dogtooth tuna and the risk of being cut off the bottom is almost zero unless the fish has been shot in really shallow water like some areas of Victoria.
Step 6. Caring for your catch
Unlike other species, the work of bringing home a Bluefin Tuna isn't done once it's in the boat. This is because Bluefin Tuna maintain a body temperature of 24-35 degrees, and if the fish is not cooled properly it could rot before you get back to shore.
There's actually a process that's critical to ensuring you can dish up a fresh plate of tuna. Make sure you’re familiar with this process and have all the equipment necessary on the boat - otherwise you’ll go home empty-handed after all your hard work.