THE flathead would have to be one of the most popular and iconic fish species in Australia. That statement is sure to start an argument but let me explain. While the various species of “flatty” may not have the status of barramundi in the north or snapper in the south, they are one of few species of recreational interest that occur in every state and territory of Australia (OK, with the obvious exception of the land locked ACT). What’s more they are relatively easy to catch using a range of techniques, have a unique appearance and are very tasty on the plate. What’s not to like?
Of the dozens of different species of flathead, when it comes to their performance and popularity as a sportfish, the dusky flathead (Platycephalus fuscus) is the undisputed King (or Queen, as the case may be…more on that later). Duskies, also known as lizards, frogs and crocodiles, grow to over one metre in size and occur all down the East Coast from Cairns in Queensland to the Gippsland Lakes in Victoria. Yes, Victoria! Many anglers from the northern states may not realise that dusky flathead form the basis of a small but highly-valued recreational fishery in the Garden State.
Down here though, things are a little bit different. In Victoria, duskies are available over a relatively short stretch of coastline, say from Lake Tyers in south-central Gippsland east to the NSW border. This represents the extreme southern edge of their range and requires that they get some special treatment to keep things sustainable. It’s fair to say that the management of the Victorian dusky flathead fishery has changed markedly in the last decade or two.
SPAWNING SCIENCE
According to information compiled by Victorian Fisheries Authority (VFA) scientist Dr Paul Hamer for a Dusky Flathead Symposium in 2018, dusky flathead typically spawn during the summer. Adult females congregate near the entrances of estuaries then release floating eggs into the water column where males release sperm to fertilise the eggs. This is called broadcast spawning. A large female of 80 cm in length can produce upwards of two million eggs in multiple separate spawning events over a season, more than 10 times more than a 35 cm female.
The few eggs that survive hatch into larvae a few mm long, living in the water column for up to a month. By this time, they are a centimetre long and settle to the bottom. If the estuary entrance is open, the eggs and larvae can be dispersed by currents out along the coast, providing a means of recruiting fish into estuaries other the one in which spawning occurred. If the entrance is closed, the eggs and larvae stay within their ‘home’ estuary.
The young duskies spend the rest of their first year of their lives in sheltered areas of seagrass, feeding on small crustaceans. As they grow, they become one of the alpha predators in the estuary and use ambush tactics to prey predominantly on fish, crabs and prawns. Being an ambush feeder means that they camouflage themselves amongst the bottom substrate and lie in wait for their prey to approach within striking range. Then they explode out of their hiding place to engulf the unsuspecting food item.
Dusky flathead grow quickly, with both males and females having the potential to reach over 40 cm in length within three years. After this male growth rates slow down, with few ever reaching 50 cm. In contrast, females continue to grow and can reach at least 1.2 m in length and weights of 15 kg. Most females are fully mature above 55 cm, the current upper legal limit for recreational harvest in Victoria. Males are known to live for at least 12 years and females at least 16 years.
POPULATION STATUS
Populations of dusky flathead in different estuaries vary greatly between years due to variation in survival and dispersal of the eggs and larva. Factors such as whether the entrance is open or closed during spawning season, freshwater flows and nutrient inputs, water temperature and salinity, and seagrass health also influence the recruitment of dusky flathead.
“Relatively heavy vibes are great, because you can hop them along the bottom in a similar fashion to soft plastics.”
Creel surveys conducted as part of the VFA’s Angler Diary Program provide a surrogate measure of dusky flathead populations in any given waterway by recording anglers’ catch rates, together with fish length and age, at boat ramps throughout a season and from year to year. According to VFA scientist Simon Conron, the abundance of dusky flathead has been in decline since the mid-2000s. It’s not all doom and gloom, with an increase in dusky flathead abundance in many waterways in 2010 to 2012, but then the decline continued until 2015. Since then, thankfully, populations
have stabilised in conjunction with an increase in the proportion of fish greater than 55 cm in length. Commercial fishing for duskies has been phased out, so these recent positive changes are presumably due at least in part to changes in recreational fishing regulations.
NIMBLE MANAGEMENT
When I was a kid I remember seeing the filleted frames of giant dusky flathead hung like trophies on mooring poles along the Mallacoota foreshore. At that time, for the purposes of regulation, dusky flathead were grouped with all other flathead and there were no special rules relating to them; they were all basically treated as food! Thankfully those days are long gone.
In the early 2000s, regulations began to evolve in response to increased interest from anglers in targeting dusky flathead as a sportfish using modern sportfishing equipment and techniques, along with concern about the number of large breeding females being killed. With support from angling groups, bag limits specific to dusky flathead were introduced, together with minimum size limits that eventually changed to slot limits (both a minimum and maximum legal length) to eliminate the take of large breeding females. Today Victoria has the most stringent dusky flathead regulations of all the Australian states in which they occur.
STOCKING
One of the other strategies being tested for increasing the recruitment of dusky flathead is the stocking of hatchery-bred fingerlings into some Victorian estuaries. Stocking of dusky flathead has the potential to help in the recovery of stocks because large numbers of hatchery-bred fingerlings are now available for stocking and they are likely to stay within whichever estuary they are released in (tagging studies show that very few dusky flathead migrate between estuaries).
A stocking program led by VFA manager Craig Ingram commenced in 2021 with the stocking of 40,000 dusky flathead fingerlings into the Gippsland Lakes, together with 5000 at Bemm River further to the east. This was followed by further stockings of around 40,000 fingerlings in the Gippsland Lakes in 2022, with even more planned for future years.
VFA scientists will be able to check on the success of the stocking program because they collected DNA samples from the parent fish. This will allow genetic parentage analysis to be conducted on fish caught in the stocked estuaries, whether that be via angler-collected fin clip samples or through the VFA’s regular monitoring surveys.
TECHNIQUES
The Victorian dusky flathead fishery may be slightly different to that in other states, but the fish itself isn’t. Duskies here will respond to all the same techniques used elsewhere and, to be honest, it usually isn’t very difficult to catch a flathead. No matter what technique you use though, remember to make sure your bait or lure is on or near the bottom or you simply won’t be in the game. Similarly, remembering that flathead are ambush feeders, it will pay dividends if you can take your offering to the fish, rather than waiting for the fish to come to you.
Bait still takes its fair share of lizards of all sizes, with the best being prawns and small fish…and you will get even better results if you can organise for baits to be presented alive. If using dead baits, strip baits of fish flesh also work well. Boat-based anglers can keep their baits moving by drifting over likely ground dragging baits along the bottom behind them. Shore-based anglers can mimic this strategy by slowly retrieving their bait across the bottom.
Duskies will enthusiastically attack lures of many kinds but lure fishing for flathead really came to popularity with the advent of soft plastics a couple of decades ago. Rigged on the right jig-head, soft plastic lures are perfectly suited to bouncing along the bottom right in the strike zone. The best retrieve seems to vary from day to day and between locations. Sometimes a fast, whippy retrieve in which the lure is jerked well off the bottom three or four times before being allowed drop back and pause on the bottom will work wonders. Other days a more sedate crawl along the bottom is required…so be prepared for a bit of trial and error. I have never tried the specialist big dusky technique of working an unweighted, super-sized soft plastic over shallow sandfla, previously documented by David Green in the pages of this magazine, but I intend to do so soon.
Hard-bodied lures work well too, provided you can get them close enough to the bottom. Relatively heavy vibes are great, because you can hop them along the bottom in a similar fashion to soft plastics. Flathead will come up off the bottom a short way to intercept diving lures that pass within their ambush zone. They will also come up to take lures near to or on the surface, which is an exciting way to fish but you need to be in shallow water. When targeting flathead, most anglers cast and retrieve their lures from either boat or shore, but trolling can be an effective technique too.
No matter whether you fish from a boat or bank, the best time of year is during the warmer months of summer. Search for flathead along the ledges where shallow water drops off into the deep. Right up on the shallow sandflats can be a hotspot too, especially if you can find an area that no one else has fished recently. Early in the morning is probably the best time to find such undisturbed water. The thing my sons and I really enjoy about fishing the flats is that we can get out and fish on foot.
ON THE PLATE
As alluded to above, one of the features of the dusky flathead that ensures it attracts its fair share of attention from anglers is that it is magnificent on the plate. The firm white flesh of two easily-removed fillets have made the basis of many a delicious fish dinner. Most anglers prefer to skin their ‘flatty tails’ rather than try to scale them. As always, please limit the number of fish you kill to what you really need…and remember the slot limit.
So, what are you waiting for? Thanks to the efforts of the state’s fisheries managers and angler groups, things are looking up for Victoria’s dusky flathead. Why not get out and catch some yourself this summer?
FURTHER INFORMATION
CURRENT REGULATIONS
For further information about the Victorian, search for “Dusky Flathead Symposium Victoria 2018”. See also the Victorian Fisheries Authority website.
For purposes of regulation, any flathead caught in Lake Tyers or any estuary east of Lake Tyers to the NSW border is considered to be a dusky flathead. The minimum legal length is 30 cm and the maximum legal length is 55 cm. The bag limit is five fish per angler per day. These fish can’t be filleted on the water, they must be kept whole or in carcass form until you’re away from the water. It’s okay to fillet your fish on the cleaning tables at the boat ramp.
