The Origins of New Zealand's Chinook Salmon, Oncorhynchus Tshawytscha

The Origins of New Zealand's Chinook Salmon, Oncorhynchus tshawytscha ROBERT M. McDOWALL Introduction Russia, spread further into Scandinavia, parison, the New Zealand situation is but were only briefly successful there quite unequivocal and of long-standing New Zealand's acclimatized stocks (Berg, 1977; Bakshtansky, 1980). clarity: Chinook salmon have been es of anadromous chinook salmon, Oncor Transplants of various species of tablished as self-supporting, anadro hynchus tshawytscha, are one of very Oncorhynchus to Chile generated some mous populations, primarily in rivers few unequivocally successful trans adult returns from smolts released to along the east coast of New Zealand's plants of any anadromous Pacific sea, though these do not seem to have South Island, since about 1905 salmon, and the only one of long stand persisted (Zamorano, 1991). By com- (McDowall, 1990; Fig. 1). ing (Childerhose and Trim, 1979). This lack of success is in spite of attempts to establish various salmon species in many areas, that date back to the era N when salmonids were being shipped to many and diverse parts of the world prior to about the 1930's, including such unlikely places as Brazil, Hawaii, Mexico, and Nicaragua (McDowall, 'L.-__----', 1988). Early attempts to establish ,t ''''" anadromous pink and coho salmon, O. gorbuscha and O. kisutch, respectively, Occasional fish stray into diverse in northeastern North America seem North Island rivers ultimately to have failed, despite initial signs of success (Lear, 1980). Pink salmon, transplanted to western Arctic Robert M. McDowall is with the National Insti tute of Water and Atmospheric Research, P.O. Box 8602, Christchurch, New Zealand. Minor and erratic runs in some west coast ABSTRACT-Chinook salmon, Oncor hynchus tshawytscha, are well established as anadromous and landlocked runs in New Zealand. Ova introductions during the 1870's (probably from the McCloud River, California, U.S.A.), failed to generate Major funs into anadromous stocks, but further introduc east coast rivers tions offall-run salmon ova from hatcher ies in California's Sacramento River basin Waitaki River in the early 1900's were successful and formed the basisfor existing runs. The first batch of ova in the 1900's consignments originatedfrom Battle Creek, a Sacramento River tributary, but the explicit source of later batches is not known. It seems likely that the successful runs stem from the sec Figure I. - Distribution of anadromous chinook salmon in New ond batch (1903 brood year-1904 consign Zealand, showing broad presence along the east coast of the South ment in New Zealand), probably augmented Island, intermittent and minor runs on the west coast, and occa by returns from later importations. sional stragglers appearing more widely throughout New Zealand. 56(1),1994 New Zealand is widely known for its and Leary, 1988; Behnke, 1992; ies in the upper river, including Mill stocks of acclimatized salmonids, espe Hilborn, 1992). Creek, the McCloud River, and other cially of brown trout, Salmo trutta, and "Wild" trout and salmon have be waters where chinook salmon stocks rainbow trout, O. mykiss; less well come something of a "clarion call" spawned (Cope and Slater, 1957). These known are its acclimatized stocks of among those sensitized to the issue of were waters where racks and hatcher Atlantic salmon, Salmo salar; brook protecting local stocks (White, 1992). ies had operated in earlier years to pro char, Salvelinusfontinalis; lake trout, S. This same concern is relevant to New vide salmon ova for release in many namaycush; and sockeye salmon, O. Zealand's stocks of chinook. For many other areas, including New Zealand. nerka (McDowall, 1990). The origins decades after their early 1900's estab Early New Zealand of stocks of these species have been of lishment they were not interfered with, Chinook Salmon Introductions considerable interest and confusion and hatchery releases into the rivers interest stimulated by a concern to un were minimal; however, with the devel Initial introductions of chinook derstand the stock origins of the popu opment ofenhancement technologies in salmon to New Zealand took place in lations, and confusion generated by western North America and the prospect the 1870's. In 1875 the Hawkes Bay poor record keeping when the fish were of ocean ranching both for commercial Acclimatisation Society obtained ova transported around the globe between purposes and to enhance recreational "through Dr. Spencer F. Baird, Chair the 1860's and early 1900's. The ori angling in New Zealand, extensive man of the United States Fishery Com gins of New Zealand's rainbow trout hatchery releases and transfers between mission" (Thomson, 1922). The ova, were clarified by Scott et al. (1978) and catchments were undertaken during the though originally destined for the town of the sockeye by Hardy (1983) and 1970's and 1980's (McDowall, 1990). of Napier, began to hatch as they Scott (1984). However, the source of The concerns that apply to stocks in reached Auckland, and they were re New Zealand's chinook salmon has not North America therefore have similar leased into nearby rivers; none reached been reviewed since the fish were es implications for the management of Napier. Further consignments were sent tablished in New Zealand in the early New Zealand's acclimatized chinook in 1876, 1877, and 1878, but contem 1900's, and their explicit source remains stocks. Even though these have not had porary New Zealand accounts do not a matter for speculation. millions of years of local selection to state their explicit origins; the common Questions relating to genetic and phe adapt them to the different conditions assumption has been that they came notypic differences among stocks of found in New Zealand rivers (as is true from the Baird Hatchery on California's Pacific coast salmonids have generated in North America), there is nevertheless McCloud River, a tributary of the much research interest in recent years. evidence to suggest that fundamental Sacramento. This is due partly to extensive hatchery life history parameters such as age and A history ofCalifornia salmon hatch releases, made either for enhancement size at maturity, spawning season, and eries suggests that, at this early period, or regeneration of heavily exploited relative fecundity, differ among New the Baird Hatchery was the only one in anadromous salmonid runs, or to restore Zealand river systems (Quinn and a position to provide ova for New those damaged by habitat deterioration Unwin, 1993). Zealand (Leitritz, 1970). Their source and river impoundment. There have also Among certain stocks at risk in North is largely of academic interest, anyway. been widespread and massive releases America have been the diverse chinook There is only slim evidence that ev,~n to support recreational salmonid fish salmon stocks of the Pacific coast an occasional salmon from the 187('s eries. In addition, there has been active (McDonald, 1981; Nehlsen et aI., releases may have returned to New interest in the evolution of Pacific 1991); because of the fragility of some Zealand rivers as adults, e.g. a few salmon species and stocks. of these stocks, the presence of accli rather modest-sized fish, thought by Considerable concern has grown matized chinook salmon in New some to be chinook salmon, were taken about these various hatchery releases. Zealand is of wider interest and their from rivers like the Waimakariri (3.6, Often the fish are of different (and even stock origins in North America of par 2.4, and 2.0 kg) and Waitaki (4.4 kg; unknown) genetic provenance from ticular interest. In addition, the presence Thomson, 1922), but there is as much those already present in the receiving of these stocks in New Zealand for likelihood that they were sea-run brown ecosystems, and sometimes they are of about 90 years provides a valuable op trout which abounded in such rivers and reduced genetic diversity as a result of portunity to examine changes in allele grew to this or greater size. many generations of hatchery rearing. frequencies during that period of isola One early report claimed that a fish There is legitimate concern that these tion. For this reason alone, identifica from a New Zealand river (1884) was hatchery introductions might disrupt tion of the origins of New Zealand identified as a California salmon by T. fish stocks finely adapted to local habi chinook stocks would be of interest. In H. Bean, of the U.S. National Museum tat characteristics; there is concern to particular, the stocks on the Sacramento (N.Z. Marine Department, 1885) Unfor protect the genetic integrity of locally River (Rutter, 1902) suffered severely tunately, this fish is no longer in the adapted stocks, sometimes recognized from the construction of the Shasta Dam collections of the Museum. Thomson as local subspecies of more widely dis in 1943, which prevented salmon from (1922) related several events reputed to tributed polytypic species (Allendorf reaching the many spawning tributar involve specimens of Oncorhynchus 2 Marine Fisheries Review from New Zealand rivers. L. F. Ayson, clearly thought that these 1870's intro fish northwards, and help to establish who was responsible for the later, suc ductions were probably a failure. runs in other South Island rivers north cessful introductions of chinook Ayson visited North America in 1899 of the Waitaki. And so it soon proved. salmon, and who was New Zealand's and returned with offers of salmon ova, Records of Early Chief Inspector of Fisheries from 1898, noting that supplies could be obtained 1900's Importations wrote that "apparently some fish caught from the Baird and Battle Creek Hatch in the Waitaki River have be~n identi eries and Canada's Fraser River; from New Zealand records of how many fied as belonging to the Pacific Salmons his detailed description, it is clear that consignments of chinook came to New or Oncorhynchus family," but he he visited Battle Creek, but apparently Zealand are inconsistent, some listing thought the evidence "far from compel not Baird Hatchery (N.Z.

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