Atlantic Salmon – Salmo salar – The strange and tragic story of Atlantic salmon in New Zealand
by Allan Burgess
Table of Contents
- by Allan Burgess
- Teething Problems Importing Live Salmon Ova To New Zealand
- They discovered it was better to pack ova in moss
- Some fry were held back in the hatchies for breeding purposes
- By 1906 the larger Chinook salmon had been successfully established in the Waitaki River
- Waiau River and Lake Te Anau Map
- Identifying characteristics
- Atlantic salmon worldwide distribution
- The link between the introduction of rainbow trout and the decline of Atlantic salmon
- Commercial farming of Atlantic salmon in New Zealand
Atlantic salmon were the preferred fish the early acclimatization societies really wanted to see introduced into New Zealand rivers. What’s more, they had a strong preference to establish an anadromous (sea-run) Atlantic salmon fishery rather than what they regarded as a second rate, landlocked one.
They made considerable efforts over almost a hundred years to bring their hopes to fruition. From what I can see in the literature more effort appears to have gone into the importation and introduction of Atlantic salmon into New Zealand by the early acclimatization societies than any other fish. However, there is no evidence that in New Zealand Atlantic salmon have ever run to sea to feed and returned to spawn in our rivers naturally. However, by the 1920s and 1930s, they succeeded in creating a self-sustaining landlocked fishery of good-sized fish.
Teething Problems Importing Live Salmon Ova To New Zealand
Attempts to introduce Atlantic salmon into New Zealand date all the way back to the 1850s. At a time when ocean travel was limited to sailing ships, and fish science was in its infancy, it was never going to be an easy task to secure and transport live salmon ova all the way from Great Britain to New Zealand and Australia. As you will see, these early settlers were determined to press ahead with introducing northern hemisphere salmonids into what they regarded, in New Zealand, as rivers devoid of sports fish.
German Stephan Ludwigi discovered or at least rediscovered, how the eggs of salmonids could be artificially fertilized, incubated, and hatched during the early part of the 18th century. Ludwigi found that salmon eggs could be fertilized by mixing them with milt and that he could incubate them in wooden troughs filled with gravel that had running water flowing over them.
Later John Shaw, a Scottish gamekeeper, carried out experiments that showed the rate at which the ova developed was dependant on water temperature.
Shaw discovered the rate of development could be slowed if the water was kept cold enough. This knowledge would, decades later, become crucial to keeping ova alive on the long sea journey of about three months to Australia and New Zealand.
The riskiest part of the sea journey from Britain to Australia was the two weeks spent sailing through the tropics. Without refrigeration, water temperatures could easily kill all the salmon ova on board.
The second risk factor was mechanical shock from the rough handling of the trays of ova. It was imperative that the trays did not get knocked and bumped. The first assignment from Great Britain to Australia in 1852 was a failure as were other later shipments. The reasons for such failure almost certainly being the raised water temperatures and the ova hatching early while the ship was still at sea.
A second consignment, also in 1852, did use ice to keep the water cool as it passed over the eggs in the trays. Although the supply of ice lasted for about 7 weeks it all melted long before the ship reached Australia.
A third consignment was sadly also a failure. This third lot was destined for Southland, New Zealand In 1862. It was partly paid for by the Southland Provincial Council at a cost of 200 pounds, a considerable sum of money in those days.
They discovered it was better to pack ova in moss
By 1852 it was discovered that the best way to transport salmon and trout ova from Europe to Australia and New Zealand was to pack them in moss rather than attempting to recreate a natural streambed over which cold water was passed.
By this method, the salmon ova were packed into small wooden boxes with perforated tops, bottoms, and sides. Into each box were placed layers of charcoal then ice, followed by carefully washed moss, and then covered with more moss and ice before the top was attached. These boxes were then stacked in the icehouse aboard the ship and covered to a height of nearly three meters with yet still more ice. Doing it this way must have almost frozen the ova.
Experiments demonstrated that by packing the ova in moss inside wooded boxes, which were then covered in a deep layer of ice several meters high, hatching could be retarded for at least 146 days, which was more than sufficient time for a fast ship to reach Australia.
In January 1864 using this new method 100,000 Atlantic salmon over, together with 1200 brown trout ova, and a further 2000 sea-run brown trout ova were successfully shipped to Australia. Although some of the salmon ova were left in Melbourne, most of the shipment was taken to Hobart in Tasmania.
Those seeking to establish these fish species in New Zealand asked for some of them to be on-shipped to New Zealand. Not an unreasonable request considering that the Southland Provincial Council had contributed 200 pounds towards the cost of the shipment. However, the Australians turned the New Zealanders down, arguing that none would be provided until salmon were established in the Derwent River.
Perhaps as a result of being refused, the Kiwis decided instead to arrange their own shipments from Great Britain. It was a good thing they did as the releases in the Derwent River were a total failure – bad karma maybe.
In 1868, the Otago provincial council arranged for a shipment of 100,000 Atlantic salmon to be brought over from Britain, 8000 of which made it to New Zealand still alive. According to Gerald Stokell, these came from the Tay (Scotland) and Severn (Wales and England) rivers. However, only a few hundred of these were successfully hatched. Some were sent to the hatchery on the Waiwera River, a tributary of the Clutha. Others were placed in ponds near Leith Stream in Dunedin.
The following year in 1869 a further shipment of 100,000 Atlantic salmon ova arrived in Otago, with small numbers of these being sent to Canterbury and Southland.
There were two smaller Atlantic salmon shipments to New Zealand in 1871. One of these went to Auckland and the other to Southland.
In 1873, 120,000 Atlantic salmon ova were sent to Otago, 95,000 to Southland and Canterbury 25,000.
Two years later in 1875, a further 300,000 ova arrived in Southland but for some unknown reason, not a single one hatched.
Then in 1876, there was another 90,000 ova imported to New Zealand and arrived in Bluff. Fry from these went to the Aparima River in Southland and the Ashley and Heathcote rivers in Canterbury the following year.
In 1884, there were 198,000 ova brought in from Great Brittain. Of these 120,000 were still alive when they arrived in Canterbury. About half were later released as fry all around the country including Hawkes Bay and Wellington.
The Canterbury Society obtained a large shipment from the Tweed River (Scotland and northern England) in 1885 and shared them with the Napier, Wellington, Otago and Waitaki Societies. Of these 4600 fry were liberated in the Hutt River.
Two years later in 1886, another 200,000 Atlantic salmon ova arrived. The following year another 610,00 ova were shipped in, some of which came from the Rhine River in Germany. Fry from this big arrival was released in the Selwyn River and nearby Lake Ellesmere in the hope of establishing a landlocked fishery. Others from this same shipment were sent all over the country including the North Island.
In 1889 a further 580,000 Atlantic salmon ova arrived in two shipments.
Some fry were held back in the hatchies for breeding purposes
In order to make even more fly available for release societies held back some of the fish in their hatcheries, rearing them to maturity, then stripping and mixing together the ova and milt. A further 494,000 young Atlantic salmon were released into Southland’s Aparima River as a result.
You can get some idea of the determination to establish viable populations as the importations continued. The biggest shipments arrived in 1910-1911 when a million Atlantic salmon ova arrived here. This shipment produced an incredible 930,000 fry almost all of which were released in Southland’s Waiau River. Some were again retained by the hatcheries as breeding stock so that more releases could be made later.
By 1906 the larger Chinook salmon had been successfully established in the Waitaki River
By this time Lake Ayson, who became New Zealand’s chief inspector of fisheries, had already successfully established sea-running (anadromous) king (Chinook) salmon in the Waitaki River and they were beginning to spread naturally to Canterbury rivers further north.
By 1922, more than 50 Atlantic salmon had been caught in the Eglinton and Upukerora Rivers which flow into Lake Te Anau. Atlantic salmon were observed spawning naturally in the Upukerora River and 50,000 ova were obtained from these wild-reared fish. These were the first-ever obtained from wild-reared Atlantic salmon in the Southern Hemisphere. Atlantic salmon numbers continued to increase so that by 1929 between 1000 and 1,200 were being caught by anglers each year. There was even a report of an 11kg fish caught. This achievement was the high-water mark for the Atlantic salmon in New Zealand.
By this time, Atlantic salmon was found in good numbers along the full length of the Waiau River from the sea all the way up to Lake Te Anau and its tributaries. The Waiau is the largest river in Southland. It outflows from Lake Te Anau and runs south for 10kms before flowing into Lake Manapouri. From there it flows south for 70 kilometres before entering Foveaux Strait 8kms south of Tuatapere.
Waiau River and Lake Te Anau Map
View Larger Topographic Map The Waiau River and Lake Te Anau. Click the map to zoom in.
However, there has never been any evidence that any Atlantic salmon found in the Waiau River has ever been to sea and returned to the river. Off the hundreds of thousands of Atlantic salmon fry released there by the early acclimatization societies, it appears that those fish that established themselves decided to spend all their lives feeding and spawning in freshwater. This is not to say that none of them went to sea, just that of those that may have, none are known to have returned. At the beginning of the 20th century, nothing blocked their path all the way from Lake Te Anau to the sea. It appears that most of the juvenile Atlantic salmon released into the Waiau River simply went out to sea and never came back.
According to the late Ron McDowall in Gamekeepers for The Nation, “From all of the many releases over so many years, there was but one certain large Atlantic salmon which was taken from the sea in a net off Oamaru in 1897. This single Atlantic salmon was mounted and could be seen for many years in a cycle shop in Oamaru.”
It is interesting to note that the only populations of Atlantic and Sockeye salmon to become established in New Zealand were both landlocked. Landlocked salmon do not get the benefit of feeding in the much more productive marine environment and as a result, grow to a much smaller size. Sea-run Atlantic salmon in their native North America and Europe can reach 1.5m in length and weigh 40kg. The largest caught in New Zealand weighed 6kg but most of those caught would only weigh 1 to 2kg at most. You can see big sea-run Atlantics from Scotland in the video below.
According to Gerald Stokell in his book Freshwater Fishes of New Zealand published in 1955, when it was shown that Atlantic salmon in the Te Anau system were lake-dwelling only, persistent efforts were made to force them to go to sea. This was done by introducing several million fry into the Wanganui River, in the North Island, that had been reared from Atlantic salmon ova taken from Lake Te Anau tributaries. The Wanganui River has no lakes in its catchment. None of these fish were ever seen again. Stokell was quite scathing in his assessment of this exercise and believed it contributed to the decline of the Te Anau Atlantic salmon fishery.
Various theories have been put forward as to why the Atlantic salmon in the Te Anau system are not anadromous (sea-running). The ova brought out from England and Scotland was taken from sea-run stock, and yet once reared and released as fry they decided voluntarily to remain in freshwater and breed in Lake Te Anau’s headwaters. But why?
A popular theory regarding the lake existence of these fish is that the food supply in the water is so rich that there’s no inducement for the young fish to go to sea, in consequence of which they remain permanently in freshwater (Stokell). This theory is in direct conflict with the law governing the early life of seagoing Atlantic salmon. It has been found overseas that the more abundant the food supply is the more rapid the growth of the parr in freshwater and the earlier the age at which they migrate to sea.
If the parr does not grow big enough in their first year of life, they will remain in freshwater for another year. For those individuals that do not attain the normal length for two-year-olds, they will remain the third year even though their length exceeds that at which the yearlings migrated. In some poor streams, parr may remain in freshwater for four years. Logically if there was a superabundance of food for the young fish they would migrate at an unusually young age (Stokell).
Another theory doing the rounds at the time was that the landlocked salmon had somehow interbred with brown trout. Many of the brown trout in the Waiau River are in fact sea-run fish. So why then would such hybrid offspring not be sea-running?
It should be noted that landlocked Quinnat salmon die out within two generations of being introduced, whereas the Atlantic salmon in Lake Te Anau reproduced and survived for many generations. The landlocked Quinnat salmon in Lake Coleridge and Lake Wanaka has been regularly put there by Fish & Game.
The story of the introduction of Atlantic salmon into New Zealand’s waterways is both strange and tragic. The early acclimatisation societies made enormous efforts to establish this species but ultimately failed. By today’s standards, their methods were very hit and miss. There was not a good understanding of the science involved. The whole business was conducted very much by trial and error.
Atlantic salmon succeeded for a time in the Waiau River and Te Anau system during the 1920 and 1930s but eventually failed. Once it was clear that sea-run stocks could not be established interest in the Atlantic salmon waned. They may, or may not, have been displaced in Lake Te Anau by later extensive rainbow trout liberations, or there may have been some other reason for their decline. Either way, by the time the societies decided to take remedial action it was too late and the cause already lost.
Early acclimatisation societies introduced rabbits which multiplied in parts of the country until they reached plague proportions. Then stoats and weasels were introduced to control the rabbit population. This of course later proved to be disastrous for New Zealand’s native birds. Introducing species from the northern hemisphere into New Zealand has been a risky business with uncertain, unpredictable, and sometimes disastrous results.
Atlantic salmon looks more like brown trout than they do a Quinnat salmon. The mouth is smaller than that of a Quinnat salmon. It has a long, slender caudal peduncle (the narrow part of the body to which the tail attaches). Colouration can vary. Lake fish tend to be greenish/blue on the back and silver on the sides, tending more to white. There are small dark coloured spots on the back and sides. There are no spots on the tail.
Atlantic salmon darken in colour as they enter the rivers to spawn. Unlike king and sockeye salmon, not all Atlantics die following the spawning process. Some females especially, survive and return to sea and later run the river again to lay their eggs. They have been recorded doing this as many as three times. In this, they are more like sea-run brown trout.
The food supply available in freshwater is nowhere near as good as that to be found in the sea. Like landlocked Quinnat salmon, our Atlantic salmon found in the Te Anau system tend to be elongate and skinny. Interestingly over time, the Atlantic salmon population in the Te Anau System got smaller and smaller from the 1920s onward. Fish up to 6.6 kilos were taken in the Marine Department’s trap on the Upukeroro River, which flows into Lake Te Anau, in the 1930s.
Atlantic salmon worldwide distribution
The Atlantic salmon is widespread from the Baltic Sea and Scandinavia all the way across the Atlantic to the coast of North America including Iceland and Greenland. There is only one species of Atlantic salmon. However, the introduction of Atlantic salmon into New Zealand, despite the enormous efforts made by so many over a long period of time, can only be described as ultimately a flop.
The link between the introduction of rainbow trout and the decline of Atlantic salmon
Rainbow trout were released into the southern lakes in the mid-1920s. Up until that time the landlocked Atlantic salmon population in Lake Te Anau appeared to be holding its own. In 1931 there was one rainbow trout caught for every three or four salmon, by 1948 it was the other way around. The rainbow trout in Lake Te Anau continued to do very well while the Atlantic salmon went into steep decline.
By 1963 Atlantic salmon made up just 6 per cent of the catch in the Te Anau system. Just as bad they were all small fish weighing only 1 to 1.5 kg. Around this time the Wildlife Service realised the species was in big trouble and something had to be done to save it. They decided to catch some of the fish from the spawning run in the Upukeroro River and transfer them to Lake Douglas, which is part of the Okuru River watershed. Why they should want to transfer them to Lake Douglas Ron McDowall doesn’t say. However, alarmingly, Wildlife Service rangers were unable to catch any Atlantic salmon at all. Clearly, by the early 1960s, the species was bordering on extinction in New Zealand.
In 1965 some ova was recovered from the Upukeroro River and 400 yearlings were released into Lake Douglas the following year. Perhaps, unsurprisingly, by 1968-70 it was clear Atlantic salmon had failed to become established in Lake Douglas.
In 1974, a further 29 Atlantics were caught in Lake Gunn and Lake Fergus in the upper Eglinton valley beside the Te Anau – Milford highway, with the intention of keeping them in captivity as broodstock. Of these only 10 survived being transported and becoming established at the hatchery.
There were several other attempts made to revive the Atlantic salmon fishery in the years following by raiding ova from wild fish, raising them in captivity, and retaining them as broodstock. But the writing was on the wall and these attempts amounted to nothing. As far as I have been able to determine the last known wild Atlantic salmon in New Zealand had died sometime before the 1990s.
An interesting feature of Wildlife Service management to protect Atlantic salmon in Lake Gunn around 1980 was to attempt to remove all the eels from this small 6 km² lake. It was thought that as many as 20 per cent of adult salmon in Lake Gunn had scars from eel attacks. Again, these measures were too little too late.
Are there Atlantic salmon in New Zealand? No.
Where there Atlantic salmon in New Zealand? Yes!
Commercial farming of Atlantic salmon in New Zealand
In the 1980s commercial interests attempted to ocean ranch Atlantic salmon at Stewart Island with stock obtained from the Wanaka hatchery but the species proved difficult to grow to commercial size. Also working against their success was the very limited gene pool of landlocked Atlantic’s obtained from Wanaka. Perhaps surprisingly, these fish adapted to the saltwater environment well despite having lived for generations in freshwater. Attempts to farm Atlantic salmon at Stewart Island were soon abandoned.
Atlantics are however farmed successfully by ocean ranching on the west coast of Tasmania. Indeed in the northern hemisphere, there are more farmed Atlantic salmon produced than any other salmonid.
The only salmon farming in New Zealand is King salmon, also known as Chinook or Quinnat salmon. Whereas in the rest of the world, and particularly in northern Europe, Atlantic salmon farming is more common.
To The Journey’s End: The Lifecycle of the Atlantic Salmon. Filmed in the North East of Scotland.
- Gamekeepers for the Nation – by R.M McDowell.
- New Zealand Freshwater Fishes – A Natural History and Guide by R.M. McDowall.
- Swimming Upstream – How Salmon Farming Developed In New Zealand by Jennifer Haworth.
- Freshwater Fishes of New Zealand by Gerald Stokell.
- Freshwater Fishes of New Zealand by Stella McQueen.
- Native and Introduced Freshwater Fishes by C.S. Woods.