One of the five species of Pacific salmon, the quinnat, also called chinook, king, or spring salmon, was acclimatised and is running in rivers of the east coast of Canterbury and north Otago. Quinnat are cold-water fish and their occurrence along the New Zealand coast seems to be controlled by the extent of the sub-Antarctic currents. Strictly speaking, quinnat salmon are ocean dwelling, ascending rivers in autumn (February-April) only to spawn, but it is only during this migration that they are fished for by anglers. Their movements while at sea are not known. Quinnat salmon are New Zealand's largest freshwater fish (except for the occasional large eel). Adults are 15–20 lb in weight, with a few reaching 25 lb. They are silver in colour, tinted a faint pink or orange, with the back a greenish brown on which are numerous darker spots; although after a few weeks in fresh water they become darker overall as they mature and, after spawning, die. Spawned fish have badly eroded tails and often become infected with a white fungus before dying. In most New Zealand salmon rivers they spawn in stable tributaries in the foothills, although suitable spawning gravels occur a few miles from the mouth. Eggs are laid in large redds similar to those made by trout, but located in deeper and swifter water. They hatch after two months, the young fish (parr) staying and feeding in the same area. Then the following autumn the parr markings disappear and the fish (smolts), now silvery and about 4 in. long, migrate downstream and enter the sea, returning in two to four years as adult salmon. About 50 per cent of the salmon spend three years at sea. A few smolts go to sea during their first summer, the majority in the autumn, and some remain in the river until their second year.
by Lawrence James Paul, B.SC., Fisheries Division, Marine Department, Wellington.