Quinnat Salmon – Oncorhynchus-tshawytscha – introduced by 1905

Also called King, Chinook and Quinnat Salmon

Also known as King salmon and Chinook salmon, this species was successfully introduced into New Zealand from North America by 1905. In that year, salmon returning to the Waitaki River were observed to be spawning naturally. From then on salmon continued to disperse to other rivers along the South Island’s east coast.

The Chinook is the heaviest and least abundant of the five native salmon species found along the west coast of the United States and Canada.

The average weight of those caught in New Zealand is between 10 and 23 pounds. Up until the mid-1990s, it wasn’t unusual for Chinook salmon weighing 26 to 34 pounds to be caught in Canterbury rivers. These were older four-year-old fish. Chinook salmon have been recorded in North America weighing over 100 pounds. You can read more about the more recent plight of the salmon in Canterbury here Poor Salmon Returns – Where have all the salmon gone? Kingfish Rising!

After 1905 Acclimatization Societies, and later Fish and Game Councils, have continued to rear salmon from stripped ova taken from returning salmon, and have distributed the offspring to other rivers and lakes. Quinnat salmon fingerlings introduced to New Zealand freshwater lakes do not spawn. These lake fisheries are instead maintained by continuous ongoing introductions by Fish and Game Councils.

Wild runs are now well established on the east coast of the South Island. There are smaller runs in some South Island West Coast Rivers. It has not been possible to establish salmon runs on the North Island of New Zealand.

Fertilized salmon eggs laid in high country streambeds hatch after two to three months depending on water temperature. The young salmon, known as parr, remain in freshwater for between 3 and 10 months as they migrate downriver to the sea and it’s rich supply of prey.

Adult salmon remain at sea for 2 to 3 years before returning to the same river where they were reared to breed and die; so completing the cycle. While at sea 76 per cent of their diet was shown to consist of sprats according to a publication released by Gavin James of NIWA. His study was the results of several years of work analyzing the stomach contents of over 800 Chinook (or quinnat) salmon taken at sea off the Canterbury coast. Chinook salmon and their distribution in New Zealand – NIWA.

When salmon first return to the rivers from the sea in summer they are bright silver in colour. These salmon have stopped feeding. Fish caught further upriver as they head to their spawning grounds lose condition and become darker and reddish in colour. Sometimes become sunburnt on their backs.

Although quinnat salmon grow to weigh as much as 130 lb (59 kg) in their original native North America, salmon caught in New Zealand usually weigh much less, with the average returning fish being in the region of 5 to 10 kg. In New Zealand, a really big specimen might weigh 42 pounds at the most. You can see here the winning fish weights for salmon entered in the Waitaki Salmon Fishing Contest. A really big New Zealand quinnat salmon would weigh 16 kg.

Video: This series of videos captures a pair of sea-run Chinook Salmon spawning twice in the same Redd in a Canterbury stream bed. The Spawning acts in the video are at 5:15 and 13:45. Video courtesy of Kevin Belcher.

The Heaviest Chinook Salmon

For the heaviest Chinook salmon, you would need to go to places like the Kenai River in Alaska, or the Colombia River in British Columbia, Canada and the United States of America, and other big rivers on the western seaboard of North America. The biggest king salmon ever caught was a 126-pound monster that was caught in a fish trap near Petersburg, Alaska in 1949. You can see photographs of ten of the heaviest monster Chinook or King salmon caught here at Fish With JD.

The salmon we have in New Zealand’s South Island originally came from North America. They are the same species but in New Zealand, they grow to less than half the size of their North American cousins. There are several possible reasons for the size difference.

Firstly, Our braided Canterbury Rivers are much shorter in distance from the sea to the spawning grounds. Whereas in the Western United States and Canada King salmon often have to travel hundreds of miles upstream to spawn. Bigger fish have an advantage when it comes to making these long upstream journeys.

Secondly, the food supply for King salmon while they are at sea may be better and more abundant in North America.

Thirdly, water temperatures both at sea and in their spawning rivers may be better suited to the species. In Canterbury, over summer both sea and river temperatures can be a bit too warm and are not ideal for salmon.

Here is a couple of the heaviest sea-run salmon ever caught in New Zealand. 

Allan Pratt, 41 lb salmon caught in the Waitaki River.

Norm Thackwell, 42 lb salmon caught in the Waimakariri River.

Global Warming

As an interesting aside, as sea temperatures increase as a result of global warming some species of salmon in North America have tended to drift to the colder northern rivers and parts of the Pacific Ocean. Perhaps we are seeing a similar thing happening in New Zealand where the decline in the salmon fishery experienced over the past 25 years may be a result of increasing sea and river temperatures.

The most notable changes in Canterbury have been the decrease in salmon numbers and fish size. Higher water temperatures at sea affect the abundance of the salmon’s prey species in the marine environment.  

Smaller hen salmon carry fewer eggs so this in turn potentially reduces the size of the wild salmon population. It is also interesting to note that there has been a decline in the size of Chinook salmon in North America over the past 40 years, with the steepest reduction in fish size taking place over the last 15 years. The Reference University of Washington: Largest Chinook salmon disappearing from West Coast.

This video by Kevin Belcher captures juvenile chinook salmon which have developed from “fry” to become “parr” and are about 40-50mm long. They will remain and feed in the stream until they become “smolt” and large enough to migrate to the sea. The survivors will return to the same stream in 2-3 years’ time as fully grown adult salmon.