Southern bluefin tuna fishing
As I write this article, massive southern bluefin tuna are being taken off the Victorian ports of Apollo Bay and Port Fairy. Many miles offshore, in the chill waters of the Southern Ocean, some incredible fish of well over 100kg are being landed, with many more lost in the course of these epic tussles.
Yep, the big southern bluefin are back, and their welcome reappearance is prompting questions like, “Where have they come from?” and, more poignantly, “Where have they been?” at busy boat ramps up and down Victoria’s southern coastline.
The answers to those questions aren’t easily found, but in this article TrailerBoat will do its best to shed some light on the great “SBT” enigma…
Victoria’s southern Bluefin tuna season begins
Before 2006 some big bluefin had been hooked in Australia’s southern waters, but mainly out of Port MacDonnell, South Australia. Then, in March 2006, south-western Victoria’s angling history was rewritten.
Ken Hinze and Cameron Ordner, from the Victorian hamlet of Port Fairy, headed out one day in hope of hooking some deep sea trevally. However, what they stumbled upon was nothing short of the holy grail of tuna fishing — a truly massive school of large, hungry, southern bluefin.
Trolling some 50km offshore, Ken spent over four hours fighting an 84kg specimen. He eventually triumphed — the feat marking the first big southern bluefin caught off Victoria.
That day kicked off what is now regarded as the greatest period in Victorian gamefishing history. Loads of big tuna were caught over the next week, including over 50 examples of 80kg-plus specimens that were landed out of Portland on just the one day (April 6). I was one of many anglers fortunate enough to take part in that mind-blowing session.
Since then, big bluefin tuna have turned up fairly consistently each year. While the numbers have varied, the size of the fish have actually increased. The full moon period from March to May is normally when they are most commonly encountered, with the action spanning anything from one or two loners to huge schools.
Last year’s run of truly massive bluefin, out of Port Fairy, was extraordinary. The catches averaged 100kg-plus, and included at least two truly awe-inspiring fish of over 150kg. Surprisingly, these fish were caught in just 50m of water, no more than 10km out of the historic fishing port.
This year’s run of big tuna out of Apollo Bay looks set to see the trend continue, with large schools reportedly feeding off Big Reef, about 60km south-west of this fishing and tourist hotspot.
However, the most consistent port for these beasts would have to be Portland. Located just over 100km shy of the SA border, this town has in the past six years produced many barrels, with the kink in the continental shelf (known locally as “The Horseshoe”) yielding the most. The town itself offers excellent facilities for the recreational fisher, with a wide range of accommodation and a great choice of restaurants.
Fishing SBT off the continental shelf
While the majority of the big fish are found a little closer to shore, the continental shelf produces most of the action when it comes to school fish and albacore, another species that deserves a huge mention. Potential world record contenders are captured each season in these parts, with real thumpers weighing in at over 35kg.
It’s the ocean currents that determine how productive one season is compared to the next. Generally speaking, an easterly current prevails through summer due to the ever-present south-easterly winds, driving warmer surface water close to the coastline. However, when the westerly current (or Leeuwin current) starts to pump, huge “upwellings” are formed on or near the shelf.
This phenomenon is referred to as the “Bonnie Upwelling”. It’s basically a mixture of nutrient-rich water that promotes extensive plumes of krill, baitfish and other sea life — the beginnings of a food chain that stretches out across the ocean for hundreds of miles.
The shelf’s contours remain fairly static until the mainland starts to veer south-east of Port MacDonnell, SA, where it comes in around 30km offshore. It holds this line through to Cape Bridgewater, Vic, where it is only 20km from shore — though the closest ramp is in Portland, which makes it a 50km trip to the 200m line. The coastline then heads north-east, though the shelf remains accessible to the ports of Port Fairy and Warrnambool, the trip averaging about 55km from each.
After these ports the shelf becomes inaccessible to trailerboats, although the tuna are still within striking range. Peterborough and Port Campbell fishos enjoyed school tuna action last season, as did those running out of Apollo Bay.
Certainly, fishing depths of 200m to 500m are extremely productive, especially early on in the season. Come late May, June and July, schools of bluefin are encountered much closer in, generally from the 40m line onwards.
Economic impact of southern bluefin tuna fishing
Victoria’s Department of Primary Industries (Fisheries division) is currently undertaking a study into the economic impact of the tuna fishery along Victoria’s west coast. The findings will be interesting due to the broad survey area, which stretches from Warrnambool to Portland. Hopefully this will be an all-encompassing report, which takes into account not only the money spent by fishos on their regular expenses (food, fuel, accommodation, etc), but also the other wide-ranging economic spinoffs enjoyed by these smaller coastal towns as a result of the recreational pursuit of southern bluefin.
The Department estimates that the recreational take of bluefin is around 3.3 per cent of the total Australian quota of 4270 tonnes. Using recreational fishing licence revenue to fund this study not only shows how committed recreational anglers are to the fishery, but also how highly they value it. Victorian recreational fishers have very few real gamefish options, so accurately gauging the impact of the fishery and the economic benefits for related communities is crucial. Only when this sort of information is known will fishers be able to push their case for legitimate access into the future.
Southern bluefin tuna: endangered or well managed?
Accurately measuring the stock of southern bluefin tuna would also be extremely beneficial. Fishers are constantly being told the species is on the brink of collapse, while recent seasons seem to state otherwise. Here we have a fishery that, when in season, runs from west of Port MacDonnell, SA, to southern NSW and Tasmania. Bluefin are caught out of every shelf-accessible port on the same day — and across months at times — yet we are continually told the southern bluefin tuna population is critically endangered, and at five per cent of its original biomass.
If you put that coastal length in perspective — the equivalent of Cairns, Qld, to Eden, NSW — there must be an awful lot of big tuna breeding somewhere…
The current catch limit of two southern bluefin tuna per day, with only one exceeding 120cm, is fairly modest and well accepted by recreational anglers — after all, tuna are highly regarded by all who chase them, both for sport and food.
Where have they been?
So where have they been hiding? Well, we have to bear in mind that each season is different. The number of fish, the availability of bait, the weather, the current strength and more — they all affect the availability of southern bluefin.
Early in the history of catching tuna in Victoria, there were very few fishos, if any, who ventured to the shelf. It was just too far out, and — coupled with the region’s fickle weather conditions — it was simply considered too treacherous. During the late ’90s and early ’00s good runs of school fish were encountered out of Port MacDonnell, Portland and Port Fairy. Then the fish seemed to disappear, only reappearing again in 2006.
In that time, GPS systems, radar and reliable long-range weather reports changed everything. GPS systems enabled the fisher to know exactly where the shelf was, while locals in the know helped out with coordinates and tips on where the fish were most likely to bite.
Using radar, anglers can now find flotillas of boats trolling together, thereby revealing an action hotspot — kind of like having binoculars that can see around corners. The cost of such equipment keeps dropping, making them a real option for recreational fishers. For all of these reasons, and others, accessibility to the SBT fishery has opened right up, making the long trips to these plentiful fishing grounds a safe and viable option for many. Southern bluefin, we’re glad you’re back!
Originally published in TrailerBoat #270, July 2011. Why not subscribe today?