Autumn Jollytails

Peter Broomhall – RiverFly trout guide, MerseyFly photographer – lives in Latrobe and is widely recognised as the preeminent authority on Mersey River fly fishing. So when he told me how a little-known downstream migration of adult baitfish sent the local trout into a feeding frenzy, I was all ears. The Mersey is one of Tasmania’s biggest rivers. In the 1960s the Hydro Electric Commission constructed the massive Parangana Dam, 80 km up-stream of the estuary, diverting the entire flow of the upper river into the adjacent Forth valley. Predictably this had severe consequences for the fishing downstream of the dam. Since the late 1990s, however, Hydro has been obliged to release significant and stable environmental flows, and fishing conditions have improved beyond expectations. In recent years the Mersey has provided what is quite possibly the most reliable and diverse sight fishing offered by any stream in Tasmania. In the mornings, especially in the months leading up to Christmas, the trout station themselves in non-riffly currents and sip down caenid duns one after the other. In the afternoons, they leap out of the water to snatch black spinner mayflies. After dark, they ‘boof’ Paratya shrimps from the surface. And wait, there’s more. Around Christmas, big trout cruise beneath the overhanging willows looking for willow grubs. Later in summer, when the paddocks dry off, they target grasshoppers. And at any time of the year, minor flooding prompts them to tail along the grassy verges looking for spiders and earthworms. Despite all this red-letter activity, the most spectacular fishing of all happens when the trout are sprinting about amongst schools of baitfish. Early-season baitfish In lowland rivers all around Tasmania, the targeting of springtime baitfish feeders is something of an institution. Indeed baitfish have always provided the backbone of our estuarine trout fisheries, and for obvious reasons. Not only is the fishing visually spectacular, but baitfish feeders are aggressive and often attack well-presented flies with gusto. Early-season baitfish (whitebait) are generally 40–50 mm long and transparent, migrating upstream from the oceans in small, dense schools. I have always preferred to target whitebait feeders in tidal broadwaters. But in recent years Peter has convinced me that, in the Mersey at least, some of the best fishing occurs many kilometres upstream of tidal influence. Here, resident brown trout can be seen bow-waving all over the riffles, scattering frightened bait in all directions. Even the trout in the pools get in on the act, lying in wait under overhanging willows or in bankside cavities, then periodically punching out into the current, producing showy eruptions of splash and noise. I’ve never been able to sate my appetite for baitfish feeders, and several years ago when fishing with Peter on the Mersey during the last vestiges of the whitebait run, I subjected him to my usual lament about the brevity of the event (which often doesn’t get underway until September, and even in the best years is usually over by mid-December). “You don’t fish in April?” Peter said incredulously. Late-season baitfish Peter went on to tell me about an annual downstream migration of adult galaxias in the Mersey River. “The jollytails school-up as they move downstream, and trout hammer them in the riffles and pools. It happens late in the season, whenever you get a bit of rain, say 20 mm. The river doesn’t have to rise much, but as soon as there’s a bit of colour in the water, it’s on. April can be very good. It’s a pity the season is closed during May, because that’s often when the action comes to a real head.” “Is it easy fishing?” I pressed. “Unlike whitebait feeders, these trout are super-bold and will eat almost any wet fly, the bigger the better. I use a #6 green Marabou Muddler, though a green or black Fuzzle Bugger can be just as effective. A good shot is almost certain to be taken immediately. In fact any shot that’s somewhere near the mark will probably be found soon enough. The trout sprint, bow-wave, pounce. You can easily bag a dozen fish in a session – including two- and three-pounders – but I often get preoccupied with filming them.” To prove his point, Peter emailed me some of the video footage he shot the previous April. In the opening sequence he zooms in on a single brown trout swirling around amid a frenzy of panicking galaxias. Then he pans out and you can see that the trout is only one of a group, all seemingly working in sync. Whitebait and jollytails Peter’s observations prompted me to read the entries on sea-migratory galaxias in Robert McDowall’s Freshwater Fishes of South-eastern Australia and The New Zealand Whitebait Book. Whitebait, it seems, is a generic name used the world over to describe a variety of small, transparent fish, which school-up and are eaten ‘whole and en masse’. In Tasmania, the term is used for springtime runs comprising several species including the Tasmanian whitebait (Lovettia sealii), four species of galaxias and one species of smelt. The Lovettia are year-old adults returning upstream to spawn and die. Most of the galaxias are juveniles which were washed to sea shortly after hatching and are returning to fresh water to live out their adult lives. Little is known of the life history of the smelt, but their contribution to the whitebait runs is relatively small. Lovettia are normally dominant from July to September, whereas galaxias are more common from September to December. The most common of the galaxias is G. maculatus. In New Zealand the whitebait runs are comprised of up to five species of galaxias, but again G. maculatus is by far the most common and best known. In many rivers it accounts for nearly the whole whitebait migration. According to McDowall, whereas most species of sea-migratory galaxias spawn near their normal adult habitat, G. maculatus always migrates downstream. ‘In Australia and New Zealand this migration always occurs in Autumn during the full and new moons so as to coincide with high springtides in the preferred spawning habitat at the head of the estuary.’ Galaxias maculatus Throughout south-east Australia Galaxias maculatus is known as the common galaxias or jollytail, though you often hear fisheries biologists refer to them as maculatus, or ‘macs’ for short. In New Zealand they are universally known by the Maori name ‘inanga’, though old hands sometimes used the term cowfish for the way their milt makes the water go milky during mass spawning. Whatever you call them, they are one of my favourite native fish. As a kid I kept them in my aquaria and soon discovered that they were much more hardy than other galaxias. Adults easily tolerated being transferred directly from fresh water to salt and vice versa. And juveniles quickly grew to be as big as Cuban cigars. As I grew older I came to appreciate maculatus even more. I’ve seen trout feeding on them in Patagonia and on Tierra del Fuego and the Falkland Islands. According to McDowall they are also native to the trout-free Lord Howe Island and Chatham Islands, making them one of the most widely distributed freshwater fish in the world. Exactly how adult maculatus are able to detect the full and new moons remains a mystery: living upstream in fresh water they can’t possibly be aware of tidal movement. Still, the adults always arrive at the spawning grounds on a high spring tide, and with empty stomachs. The eggs are laid on the ground around the base of reeds – rush marshes are ideal – and survive exposure to the air at low tide. Early descriptions of whitebait runs in both Tasmania and New Zealand suggest that maculatus was more abundant in the past than it is now. Presumably overfishing, pollution, and dam building are partly to blame. On the other hand, maculatus seems to be more tolerant of deforestation than other galaxiid species and does surprisingly well in pasture-banked streams. In any case, most populations in Tasmania and New Zealand remain quite robust with numbers stable or increasing. Seeing is believing Last April, on the full moon, Peter rang to say that there had been a cloudburst overnight. “The trout are going ballistic on jollytails.” He even forwarded a video to back it up. I asked whether he thought the phase of the moon might have been a contributing factor, but he remained sure that water flow was the key. “When I was growing up, everyone knew that late rain in April was the time to go down to the river. It’s always worked for me. Never seen any reason to worry about the moon.” Of course I wanted to go and check things out for myself, but I had other commitments. “Let me know when it happens again,” I implored. “I’ll come up with my mate Ric.” Two weeks later, on the new moon, Peter rang once more. “It rained again last night and there’s more rain predicted for the rest of the week. Get yourselves up here.” I asked if we should fish the head of the estuary near Latrobe, or if the Great Bend some ten kilometres upstream would be good enough. “We were fishing even further up-stream. But it’s all equally good.” By late morning, after more than a three-hour drive, Ric and I arrived at Hoggs Bridge. We could immediately tell that the Mersey was flowing at a perfect height. The water had a bit of colour but was not so deep and fast that we wouldn’t be able to wade across the riffles. As soon as we geared up we started seeing fish. Some trout were sprinting across calm shallows in the tail-outs. Others were charging about in marshy esplanades. Our expectations for the rest of the day were high, and the world seemed rosy. Last year’s great scouring flood seemed to have improved access along the banks without demolishing too much structure. There was enough native scrub to offer shade and stability, and there were plenty of undercuts too. But the water began lowering quickly, and losing colour. As the afternoon progressed we saw fewer and fewer fish, and the ones we cast to became more scatty, often tapping the fly without hooking up, or following it all the way to our feet and then darting away never to return. Still, it was enough to get me well and truly inspired. Implications Peter’s revelations have left me with dozens of unanswered questions, dozens of reasons to fish harder and more methodically this coming April. Will I be able to find similar baitfish action in the lower freshwater reaches of the Derwent, Great Forester, Huon, Henty, Lune and Gordon rivers? Do migrations really occur on the full and new moons regardless of rain and water flow? Is there a similar schooling of jollytails in Tooms Lake, one of the few Tasmanian impoundments in which they thrive? What happens in New Zealand, and what are the implications for mainland waterways? Why not check out some of the local possibilities yourself. We will all be dying to hear what you discover.

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