Story & photo Mary Gardner
How did flatheads reach the top of the news last week? From May 3 to 23, the NSW government removed fishing quotas relating to these fishes in state waters (three nautical miles). Was their action a flashback to the 1940s when post-war fishing went all out working what seemed a bonanza of flatheads? But in that decade, catches fell from 2,586 tons to 958 tons. Or were they perhaps lost in a nostalgic Great Gatsby reverie of the earlier 1910-20s, when the state exclusively managed southeast trawling and marketing? The price of flatheads was heavily subsidised and they were promoted as a good, cheap alternative to meat. The Sydney love affair with fish and chips grew and the number of shops doubled in ten years.
In this venture, the state lost money and finally sold on to private owners, who tried even harder. Historical reconstructions figure that by 1937, the catch rate of flatheads was less than half than in the early 1920s. So whatever prompted the 21st century NSW ministers into such retrograde action last May, it wasn’t lessons learned from history. A word from the Commonwealth has brought NSW back to date: the commercial quotas were reinstated and the recreational ones reaffirmed.
But through all these years and politics, the commercial catches of flatheads have slumped twice. Since the 1990s, they remain under 400 tons. So exactly what are these fish?
The term ‘flathead fishery’ is an industry label featuring about a dozen species of the family Platycephalidae. If you ask at the Sydney Fish Market, ‘flatheads’ are most likely Duskies, Tigers, Blue-spotteds, Deepwaters or Southern Blue-spotteds. The flatheads of NSW trawling history mentioned above are Tiger (Neoplatycephalus richardsoni), schooling out three nautical miles or more. These have never since been caught in their former numbers. Instead, more frequently sold are Southern Blue-spotted (Platycephalus speculator), a southern coastal species. The one you might actually see around Byron Shire beaches and estuaries is more likely the Dusky (Platycephalus fuscus).
Though much the same when in batter, the living fishes are unique mysteries. Fast growing carnivores, with teeth in the roof of their mouths, their complete lifecycles are not well known. But what’s known is surprising. For instance, Dusky females grow faster and become larger than the males. They also mature later. At 57cm, half are sexually mature, this happens for males when they are 32cm in length.
So recreational catch limits allow only one fish over 70cm to be taken. Hopefully, this protects ‘big mamas’: older, experienced fish with larger eggs. At this size, they weigh nearly four kilos and are eight years old. The record catch is about nine kilos, a fish 15 years old. They spawn close to shore and in estuaries.
Meanwhile, male and female S. Blue-spotted are often caught 45-60cm in size. The smaller males mature after the first year but the females only after two years. Tiger females are larger than males but their sizes on maturity are not known.
How and where do all these flatheads grow? We don’t quite know though there are a few clues. Dusky juveniles are in mangrove estuaries. Tiger juveniles may very well range farther and deeper to the outer shelf. This hunch is based on biology: tigers have swim bladders and can move through depths at will.
Today, when ‘flathead fisheries’ pull up nets, they also bring up nannygais and morwongs. These are what we now call redfish and sea bream respectively. The state legislated changes to their names back in the 1940s, when that post-war ‘bumper crop’ of flatheads diminished and more of these were caught instead. As they were considered unpalatable, the name change was part of a nutrition campaign to improve their marketability.
Redfish and sea bream lifecycles are different again. Critically, these species are overexploited or overfished. Fishing restrictions may seem like crude government. But, given our fishing history, they are the first steps in managing ourselves as not apart from but within a complex system of species.
Mary Gardner is a biologist and writer. See more of her work at www.tangleoflife.org.