150 Years of Trout

It is 150 years since trout were successfully introduced to the Salmon Ponds at Plenty near New Norfolk. These were not just the first trout to arrive in Tasmania, but the first in the southern hemisphere, subsequently seeding waters on the Australian mainland and in New Zealand.

The Salmon Ponds remains the oldest trout hatchery in the Antipodes, and one of the oldest continually operated hatcheries in the world. It is an adorable place — the weatherboard buildings, the quaint old Huon pine hatching troughs, the tranquil lawns dotted with exotic northern hemisphere trees, the thriving waterweeds in the earthen rearing ponds. To this day it retains all the serenity of an English country estate. There’s a nice little museum there too.

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All trout fishers empathise with the original intent that underpinned the construction and operation of the Salmon Ponds, and feel a great debt of gratitude to those involved in bringing trout to Tasmania, yet these days trout hatcheries are problematic in the management of wild fisheries. Beyond maintaining stocks in traditional fisheries where natural spawning is constrained, we do need to think carefully about how and where we use hatchery fish.

The Salmon Ponds marks the point at which trout hatcheries proliferated. Even though the first artificial hatching of trout occurred more than a century beforehand, serious propagation of salmonids didn’t really get underway until 1852, when the Stormontfield Ponds — an Atlantic salmon hatchery — were built on the banks of Scotland’s River Tay.

THE TASMANIAN CONNECTION
European colonists soon discovered that Tasmania had no native trout or salmon, indeed no native fish (larger than the native grayling) that could be deemed a sporting fish. But it did have ideal salmon habitat — large rivers which flowed into cold seas. And it was this commercial motivation, to establish a salmon industry, that drove the earliest attempts.

The Tasmanian story has been well told by Jean Walker (Origins of the Tasmanian Trout, 1988). Likewise, early acclimatisation efforts have been documented in books by Jack Ritchie (The Australian Trout, 1988), John Clements (Salmon at the Antipodes, 1988) and Bob McDowall (New Zealand Freshwater Fishes, 1990).

Serious efforts commenced in 1854 when James Youl began to study ways of retarding the development of living ova so that they might survive a three to four month voyage to the Antipodes. In 1862 ponds and races (based on Stormontfield Ponds) were prepared at Redlands on the Plenty River, about 2 km above its confluence with the Derwent.

After several failed attempts, the final success came in 1864 when 100,000 salmon ova were despatched from England aboard the clipper ‘Norfolk’ under the supervision of William Ramsbottom. Although Youl had not intended to send brown trout, fearing they would outcompete his precious salmon, last-minute gifts of brown trout ova from naturalists Francis Francis (2000) and Frank Buckland (1000) were included in the shipment.

Although Youl instructed that the trout be left with Edward Wilson (for the Acclimatisation Society of Victoria) when the ship docked in Melbourne, Ramsbottom would not give them up and sent them on to Hobart.

On 21 April 1864, live ova finally arrived at the Salmon Ponds. About 30,000 salmon and 300 brown trout ova had survived.
The rest is history. Salmon failed to establish, brown trout proliferated.

BROWN TROUT ORIGINS
The original gifts of trout eggs were obtained from the Itchen near Winchester, the Wye at High Wycombe, the Wey at Alton and possibly the Test at Whitchurch.
The first fry hatched on 4 May. Of the original 300 or so trout, 40 were released into the Plenty in April 1865. The rest were retained for brood stock, ova being collected from them in the winter of 1866.

The trout from the original shipment were probably sufficient to populate the rivers and lakes of the colony. By 1866 it was considered that the acclimatisation of brown trout was guaranteed. And in 1869 the Salmon Commissioners noted that during June and July many pairs of trout of all sizes were seen along the Plenty River, ‘busily engaged in forming their nests and depositing their spawn.’

Nonetheless, in order to cement the success, in the interest of supplying ‘new blood’ and in efforts to acclimatise ‘different’ species (such as sea trout and Loch Leven trout, both now recognised as strains of brown trout), there were numerous subsequent imports.
Given the genetic diversity of the founding stock, it is hardly surprising that a range of colour variations and life-history forms have arisen throughout Tasmania and beyond.

The first successful shipment of trout ova to Victoria arrived from Tasmania on 18 August 1866, and were transported to Jackson’s Creek, Sunbury. Ritchie (1988) tells that hatching boxes were washed away in flood, but some fish must have survived because trout were being caught in the Maribyrnong system two years later. Subsequently, of course, there were numerous other importations.

In 1867 brown trout ova were taken from Tasmania to the newly formed Canterbury and Otago acclimatisation societies, partly funded by the provincial councils. These were the first consignments of salmonids to arrive in New Zealand. Here too, many additional importations occurred in subsequent years and decades, not only from Tasmania but also from England, Scotland, Germany and Italy, representing a diverse genetic heritage.

The hatchery movement in Australia and New Zealand was cutting edge, pre-dating hatchery efforts in America.

THE RISE OF HATCHERIES
Hatcheries proliferated in Tasmania, across the southeast of the Australian mainland and in New Zealand. This was not just because there were many river and lake systems to be seeded, but also because anglers were in constant fear of the fish dying out or becoming inbred. Such fears seem quaint now, but in those days anglers struggled to understand why the fish in newly stocked waters grew big and fat, then after a few generations their progeny tended to be much smaller and leaner — now simply explained by population dynamics.

Trout hatcheries also proliferated in Europe and, especially, America. Here, though, it wasn’t in order to stock new waters but rather to mitigate the environmental degradation brought about by a burgeoning population and the impacts of the Industrial Revolution. With hatcheries, so the theory went, you could continue to chop down the forests, dig up the land, channelise the rivers — the angling could be maintained simply by adding hand-reared trout to make up for those that could no longer be naturally spawned. Hatcheries could also replenish healthy streams where overkill was resulting in greatly reduced bags. It seemed too good to be true, and of course it was.

MEN OF SCIENCE
For decades, right across the globe, the rise and rise of the hatchery seemed to occur without question. There was a problem, however. In the great majority of rivers and lakes, liberations of hatchery fish failed to improve the fishing.

The first person to document this reality was New Zealand angler Derisley Hobbs. Hobbs had no formal training in biology, yet in 1948 he published one of the most influential books on fisheries management, Trout Fisheries in New Zealand: Their Development & Management, in which he highlighted the unintended negative consequences of hatcheries. His conclusion — that ‘it is a sound commonsense rule of fisheries management to leave well alone’ — caught the attention of many of the world’s leading fisheries biologists and ecologists, several of whom were eager to properly test his ideas.

In Tasmania the CSIRO soon commissioned a study into trout population dynamics, employing an Australian-born biologist, Aubrey Nicholls. Nicholls began his work in 1949, and eventually concluded that the century-old practice of boosting wild stocks of trout through releases of hatchery fish was biologically unnecessary — a waste of time and money, in fact.

Hobbs and Nicholls’ work had immediate influence in America. Biologist Paul Needham had set up a research station on Sagehen Creek, California, and one of his employees, Robert Behnke (see FlyLife #70), soon proved that wild trout — in this case non-native brookies and rainbows — in healthy water could sustain quality fishing without the need for hatchery releases. This group of fisheries scientists was amongst the first to prioritise the preservation of habitat and gene pools over the production of hatchery-reared fish as the best way of improving fishing for all.

In the late 1950s, Hobbs moved from New Zealand to Tasmania, where he was given the task of designing the structure of Tasmania’s new Inland Fisheries Commission, before going on to serve as the authority’s first head commissioner. During his tenure, Hobbs demonstrated political mastery in implementing Nicholls’ recommendations, putting Tasmania at the global forefront of sustainable fisheries management.

HATCHERIES & WILD FISH
Work in America, largely popularised by Behnke, explains how hatchery reared fish can reduce the genetic diversity that enables wild trout to maintain optimal population levels. Even in waters where trout are non-native, the effects on wild stocks can be significant. Research undertaken in the 1960s on the Madison River in Montana showed that the addition of hatchery catchables actually reduced the overall numbers of fish in the system.

The reasons for this are manifold. Hatchery fish disrupt wild fish, making them vulnerable to all manner of stresses. Some of the hatchery fish are harvested quickly, while others don’t fare well in the wild and die prematurely. The remaining domestics and wild fish interbreed, producing offspring that are not as well equipped for life in the wild.

The Madison was rehabilitated by simply abandoning the stocking program and limiting the kill — simple, cheap and ultimately popular. Until recently most researchers suspected that it would take multiple generations to see genetic evidence of domestication, but the authors of an article published in the Proceedings of the National Academy of Sciences in 2011 found that when steelhead eggs are taken from the wild to a hatchery and the hatchlings on-grown, the resulting smolts are already genetically distinct from wild fish and have difficulty surviving in the wild. It is not yet known which genetic trait is being (unintentionally) selected for in hatcheries, but it is likely to implicate overcrowding.

In waters where trout are native, they have had thousands, tens of thousands or even hundreds of thousands of years to fine-tune themselves to the environment. In these cases genetic adaptation is already optimal and the impact of hatchery fish can be understandably severe.

In hitherto trout-free waters — like Tasmania in the late 1800s — newly released trout evolve quickly. In part this is because they do not have to compete with wild trout so their survival rate is relatively high. It also helps that they can produce thousands of offspring at a time. In the Kerguelen Islands, trout from a single source were distributed amongst several independent river systems, and evolutionary pressures were so great that twenty years later the various populations were found to be genetically distinct from one another.

Behnke stresses that natural selection processes operating for more than a century in Tasmania and New Zealand will have fine-tuned our brown trout to their new environments, resulting in genetically distinct populations that are optimally suited to their respective lakes and rivers. So in waters where populations remain self-supporting we must think twice before introducing hatchery fish.

Let’s hope that those fisheries managers stocking hatchery raised barramundi, bass, perch and cod far and wide across the warm waters on our mainland have taken time to study the mistakes made in managing wild native salmonids across the world.

MAINTAINING WILD STOCKS
In 1959 the highly respected and in-fluential American organisation Trout Unlimited was founded explicitly to promote the value of wild trout. It defined wild fish as those which were ‘river-born’ (or lake born) rather than those which had been hatched or raised in a hatchery.

In 1964 the term ‘catch and release’ was coined, and anglers everywhere began to accept that the key to maintaining healthy fisheries was to embrace the preservation and restoration of habitat.

Yellowstone National Park became one of the first major public fisheries to experiment with enforced catch and release. After some trial and error, park authorities eventually found a combination of bag and size limits which restored a seriously underperforming cutthroat trout fishery to its historic best. This success led to catch and release regulations being adopted worldwide.

What wasn’t really understood at the time was that the ‘recycling’ of fish would only result in improved angling under certain circumstances. It turns out that, in most places, catch and release is only necessary when the annual harvest of fish approaches or exceeds fifty per cent. Such catch rates are common in cutthroat trout waters, but much less common in brown trout waters.

Generally speaking, effective fishery conservation these days is all about environmental protection and improving advocacy through increased participation. Education is critical too: anglers need to understand what wild fish are, and why they are important.

THE VALUE OF WILD TROUT
To this day Tasmania’s trump card is still its wild brown trout: diverse, beautiful to look at, hard fighting, difficult to catch. Wild fish offer excitement, variety, serendipity, and endless scope for honing your fly fishing skills. No matter how proficient we grow to be, there are always old challenges to overcome and new ones to discover.

Anglers travel the world seeking truly wild fish, even of modest size. Behnke notes that ‘wild trout, even non-native wild trout, have a very real intrinsic value, an intangible aesthetic value best extolled by Roderick Haig-Brown.’

Then there is the more pragmatic issue of cost. Behnke reviewed the evidence and came to this conclusion: ‘The value to the economy of an angler spending a day fishing for wild trout is always higher than a day spent fishing for hatchery-reared catchables.’ Stocking, he insisted, is best done in ponds and small lakes, with good access. ‘Here the percentage return is much, much higher than for fish released into streams or large lakes.’

THE FUTURE
2014 is a time to celebrate, and to remember. We anglers have a debt of gratitude to those who worked so hard to introduce trout to the Antipodes. The Salmon Ponds is a charming historical site that every angler should visit at some time in his life.

But this is a cautionary tale. Beyond specific recovery programs and the stocking of lakes where natural spawning is limited, there is not much of a place for trout hatcheries in modern times, not if we wish to maintain vibrant wild fisheries which will remain stable and affordable well into the future.

From FlyLife Issue 76