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expected value. However, a sex ratio of 1 .03 : 1 was derived from 9 years of Sea
Survey data. The most important difference in sampling appeared to be that Sea
Survey cruises covered a more extensive area than the commercial fishery. Data
from Sea Survey cruises during "February", "April", and "May-June", included
many samples with a preponderance of one sex (Figure 6). These same cruises
provided information which suggested a temporal and spatial difference in the
sex composition of the population (Figure 5).

Whether anchovies segregate by sex over large areas or within schools or
loose aggregations is difficult to ascertain. Continued occurrences of high female
to male ratios from the fishery support a theory of a wide spatial difference in
the sex composition. Because of the effectiveness of the purse seine, fishermen
often captured the major portion, if not all, of the anchovy school they were
setting on. It is assumed then that the samples from the fishery reflected the sex
ratio of the anchovy schools in the areas fished. The ratios of these samples most
often favored females and indicated the fishery was harvesting primarily portions
of the population that exhibited a dominance of females.

The possibility exists that the sexes only loosely segregate and that they have
a differential vulnerability to gear at different times and places. Concentrations



208 CALIFORNIA FISH AND CAME

containing mostly males may not form the large dense schools necessary for
effective purse seining. Acoustic surveys found very few commercial size
schools in the area southeast of San Clemente Island where males dominated.
Also, schools with more females may have been easier to locate because of
some difference in activity or density within a school.

Sampling bias may explain female dominance in fishery samples. For example,
did the sampler tend to select larger (female) fish? There is no evidence, at this
time, which either supports or rejects this suggestion. Did females have a higher
fat content and segregate either in the vessel's hold or in the net after it was
pursed alongside the vessel? Anchovies were sampled using a stratified random
sampling plan with subsampling without replacement. Some mixture occurred
in the offloading process because of the use of a wet pump. It would be difficult
even to try to sample from the same portion of each vessel's load and, if we
assumed that segregation occurs after capture, then dominance of males in
samples would be more evident.

For some reason there may have been more than a loose segregation by sex.
Evidence included the seemingly unexpected but frequent occurrence of 24:1,
23:2 and 0:25 type samples from Sea Survey cruises and less frequent occur-
rences of daily sex ratios as high as 6:1 (Figure 4) from the commercial fishery.
One additional bit of evidence was a personal observation of the sexing of more
than 350 anchovies from one mid-water trawl, of which only two were females.

I believe the sex ratio of the anchovy population off southern California is
reasonably close to the 1:1 ratio expected, but that at times spatial segregation
of sexes occurs. How and why this segregation occurs is mostly a matter of
conjecture at this time. The seasonal appearance of abnormally high sex ratios
for sea survey samples at a time when spawning was known to be occurring
(MacGregor 1968) suggests some behavioral mechanism. Any further supposi-
tions based on available data seem fruitless at this time. However, the commer-
cial fishery as a sampling mechanism of the anchovy population off southern
California is clearly biased. Additional supporting evidence (other than sex
ratios) is the fact that the age composition of the landings and of Sea Survey
samples differ markedly with a relatively weak representation of older year
classes from the former (Mais, Calif. Dept. of Fish and Game, pers. commun.).
Although fisheries biologists have maintained for years that the anchovy could
sustain a much larger harvest, they seldom concerned themselves with the
possibility that the sampling data from the commercial fishery presents a distort-
ed picture concerning year-class strengths, mortalities, etc. These implications
are no doubt important to population dynamicists and deserving of their atten-
tion.

ACKNOWLEDGMENTS
I would like to extend my thanks to Eric Knaggs, Kenneth Mais, Herbert Frey,
and Timothy Farley for their critical review of this manuscript.

REFERENCES

Collins, Robson A. 1971. Size and age composition of northern anchovies (Engraulis mordax) in the California
reduction and canning fisheries, 1968-69 season. Calif. Fish Came, 57(4):283-289.

MacGregor, John S. 1968. Fecundity of the northern anchovy, Engraulis mordax Cirard. Calif. Fish Came,
54(4):281-288.

Mais, Kenneth F. 1969^. California Department of Fish and Came fisheries resources sea survey cruises, 1966.
Calif. Mar. Res. Comm., Calif. Coop. Oceanic Fish. Invest., Data Rep., (16):1-85.



NORTHERN ANCHOVY SEX RATIO 209

19696. California Department of Fish and Came fisheries resources sea survey cruises, 1967. Calif. Mar.

Res. Comm., Calif. Coop. Oceanic Fish. Invest., Data Rep., (171:1-106.

1971a. California Department of Fish and Came fisheries resources sea survey cruises, 1968. Calif. Mar.

Res. Comm., Calif. Coop. Oceanic Fish. Invest., Data Rep., (18):1-181.

19716. California Department of Fish and Came fisheries resources sea survey cruises, 1970. Calif. Mar.

Res. Comm., Calif. Coop. Oceanic Fish. Invest., Data Rep., (20):1-138.

1972. California Department of Fish and Came fisheries resources sea survey cruises, 1971. Calif. Mar.

Res. Comm., Calif. Coop. Oceanic Fish. Invest., Data Rep., (21):1-132.

1973. California Department of Fish and Came fisheries resources sea survey cruises, 1972. Calif. Mar.

Res. Comm., Calif. Coop. Oceanic Fish. Invest., Data Rep., (22):1-88.

1974,3. California Department of Fish and Came fisheries resources sea survey cruises, 1973. Calif. Mar.

Res. Comm., Calif. Coop. Oceanic Fish. Invest., Data Rep., ( 23) :1 — 1 13.

19746. Pelagic fish surveys in the California Current. Calif. Dept. Fish and Game, Fish. Bull., (162):1-79.

1975. California Department of Fish and Came fisheries resources sea survey cruises, 1974. Calif. Mar.



Res. Comm., Calif. Coop. Oceanic Fish. Invest., Data Rep., (24):1-82.

Pinkas, Leo. 1951. Yield per area of the California sardine fishing grounds, 1937-1949. Calif. Dept. Fish and Came,
Fish. Bull., (80):1-14.

Smith, Paul E. 1972. The increase in spawning biomass of northern anchovy, Engraulis mordax. Nat. Mar. Fish.
Serv., Fish. Bull., 70 (31:849-874.

Spratt, )erome D. 1972a. The use of otoliths to separate groups of northern anchovies, Engraulis mordax. Calif.
Dept. Fish and Game, Mar. Res. Tech. Rep., (11:1-25.

1972. Age and length composition of northern anchovies, Engraulis mordax, in the California anchovy

reduction fishery for the 1969-70 season. Calif. Fish Game, 58(2) :1 21-126.

1973a. Age and length composition of northern anchovies, Engraulis mordax, landed in California for

reduction during the 1970-71 season. Calif. Fish Game, 59(21:121-125.

. 19736 Age and length composition of northern anchovies, Engraulis mordax, in the California reduction



fishery for the 1971-72 season. Calif. Fish Game, 59(41:293-298.
Sunada, John S. 1975. Age and length composition of northern anchovies, Engraulis mordax, in the 1972-73
season, California anchovy reduction fishery. Calif. Fish Game, 61 (31:133-143.

Vrooman, Andrew M., and Pedro A. Paloma. 1975. Subpopulations of northern anchovy, Engraulis mordax
mordax. Nat. Mar. Fish. Serv., Admin. Rep., (LJ-75-62) :1-10.



210 CALIFORNIA FISH AND CAME

Calif. Fish and Came 64(3): 210-218. 1 978

THE ORIGINS OF RAINBOW TROUT,

SALMO GAIRDNERI RICHARDSON,

IN NEW ZEALAND n

by

D. SCOTT

Department of Zoology

University of Otago
Dunedin, New Zealand

J. HEWITSON

1033 San Abella Drive

Encinitas, California 92024

and

J. C. FRASER 2

California Department of Fish and Game

Yountville, California 94599

The origins of the rainbow trout in New Zealand have long been the subject of
controversy. The Baird Station on the McCloud River and the Russian River in Cali-
fornia have been popularly named as principal sources. A search of records and
literature in both New Zealand and America reveals rather conclusive evidence that
the 1883 shipment of trout eggs to New Zealand originated from steelhead rainbow
trout in Sonoma Creek, a tributary to San Francisco Bay. Progeny from this 1883
shipment were widely distributed throughout New Zealand, resulting in many self-
sustaining populations. The Russian River as a source for these eggs is refuted. An
earlier shipment of eggs in 1878 could well have been from cutthroat trout, the
common native species of Lake Tahoe (California) from which the eggs were report-
edly shipped. Other shipments in the late 1800s from the McCloud and Shasta rivers
and in 1930 from Lake Almanor in California are discussed but are not considered
to be as important as the 1883 shipment.

INTRODUCTION

The origins of the successful rainbow trout in New Zealand have long been
the subject of controversy among trout anglers and fishery biologists. It is well
known that they were shipped in 1883 from California via San Francisco and
were received by the Auckland Acclimatisation Society, but the records were
not clear in respect to the waters from which they originated.

The importance of genetically distinct stocks in relation to acclimatization has
been recognized by several workers (Pautzke and Meigs 1940, Neave 1949,
Shapovalov and Taft 1954, Ricker 1954, Needham and Card 1959, MacCrimmon
1971, and Ricker 1972). Both migratory and non-migratory populations exhibit
the genetic diversity necessary for speciation (Mottley 1954). Loss of rainbow
stocks by seaward migrations has caused Tasmanian authorities to abandon
stocking rainbow trout in rivers with access to the sea. (Lynch, Commissioner
Inland Fish, Tasmania, pers. comm.)

With few exceptions, American fisheries literature has perpetuated the belief
that Baird Station on the McCloud River in California was the source of nearly
all exports of rainbow trout eggs to other countries, including New Zealand.
Dollar and Katz (1964) put it typically: "From these McCloud River trout have
been developed most of the hatchery trout stocks used today in U.S., Europe,

' Accepted for publication December 1977.

2 Present address: Environment Protection Authority, Melbourne, Australia



ORIGINS OF NEW ZEALAND RAINBOW TROUT 21 1

New Zealand, and other countries".

The tendancy to rely on the primacy of the Baird Station may be due to the
fact that it represented the first government supported effort to obtain rainbow
trout ova for hatchery purposes in the U.S.A. Since the Baird Station was the
major fish cultural operation at the time and was gathering, hatching, and dis-
tributing McCloud River trout eggs as well as chinook salmon, Oncorhynchus
tshawytscha, in the late 1800's, it was logical for later workers to look upon it
as a probable source of rainbow trout egg shipments to New Zealand, especially
in the absence of any information to the contrary.

When New Zealand sources are examined there is no mention of the Baird
Station and only oblique references to the McCloud River as a source for later
shipments. Hobbs (1948) cited a reference which indicated that these eggs
came from the Russian River, a coastal stream in California. A further treatment
of this view is provided later in this paper. Another New Zealand view is that
expressed by Stokell (1955), who believes that at least one source of New
Zealand rainbows was Lake Almanor, California.

NEW ZEALAND RECORDS

The earliest record of a relevant importation was in 1878 by the Auckland
Acclimatisation Society (A.A.S.). The Minute Book of June 10, 1878 notes the
arrival of 10,000 eggs of trout from Lake Tahoe (California/Nevada, U.S.A.), a
gift from Mr. T. Russell. Mortality was high, however, and by July 1, 1878 only
350 young fish were alive for distribution. The Minute Book of July 1, 1878
records the resolution that these fish were to be distributed in Lake Takapuna,
some of the Waikato lakes, and Lake Omapere.

The Minute Book of August 5, 1878 records the arrival of 5,000 healthy ova
from the same source as the previous shipment and the minutes for September
2, 1878 state that 2,000 young trout were available for distribution. The distribu-
tion of this second lot was left to the chairman and no locality is given. No further
mention of this stock occurs in the records and it is not possible to say whether
any individuals survived. Of the localities mentioned, Lake Takapuna was suita-
ble for trout, as rainbows from a later shipment released in this water appeared
to survive and grow (Ann. Report., A.A.S., 1888). Survivors of the Tahoe stock
could have been overlooked with the success of later shipments.

The uncertainty extends also to the species comprising the 1878 consignment.
The Lahontan cutthroat trout, Salmo clarki henshawii, was native to Lake Tahoe,
and a rainbow trout, Salmo regalis, was reputed to be the native rainbow trout
of Lake Tahoe (Snyder 1933). The status of Salmo regalis is now in doubt and
it is now believed not to have been indigenous to Lake Tahoe (Behnke 1972).

The identification of trout species and the use of common names was some-
times a rather informal process among the fish culturists of the 1 870's and 1 880's.
Common names were often applied as a matter of personal or local preference.
Some early fish culturists attached little importance to species separation and
some were known to change the common names on shipping labels so that the
receiver would be "guaranteed" satisfaction. Thus, the common names under
which many of these early shipments were made cannot always be relied upon.

Since the native trout of the Lake Tahoe area was the Lahontan cutthroat, it
is possible, although not certain, that the 1 878 shipment was of this species rather
than rainbow. If, in fact, they were cutthroat trout, it raises a question of possible



212 CALIFORNIA FISH AND CAME

hybridization in the New Zealand waters where they were planted and where
subsequent stocking occurred with rainbow trout. Where this has happened in
America the rainbow usually dominate, and the cutthroat gradually disappear
through the processes of competition and hybridization.

The 1883 Shipment

The most widely recognized importation, that of 1883, has been referred to
frequently (Ayson 1908, Thomson 1922, 1926, Hefford 1926, Hobbs 1948). It is
interesting to note that the Auckland Acclimatisation Society showed no inten-
tion of importing rainbow trout and was not aware of the correct identity of the
shipment for several years. How this anomalous situation actually occurred will
probably never be determined but the details are worth examining.

The Society was interested in developing the char or brook trout, Salvelinus
fontinalis, and attempted to obtain some from California:

"An order was also forwarded to San Francisco for ova of the well known

brook trout (Salmo fontinalis) but for various causes it was unable to obtain

any."

(Ann. Report, A.A.S., 1881-82)

The order must have stood for it is recorded (Minute Book, February 13,
1883) that 10,000 brook trout ova from San Francisco had arrived but all were
dead.

In late February or March, 1883 two successful shipments arrived:

"The Secretary announced the arrival of 10,000 brook trout ova from San

Francisco by the "City of New York", from which 500 healthy young fish had

been hatched, and also of 12,000 ova of the same fish by the "Zealandia",

about 5,000 or 6,000 of which appeared to be in good condition."

(Minute Book April 3, 1883).

A further shipment of 30,000 ova was received from California in March 1884
(Minute Book April 8, 1884) but all were dead on arrival.

No useful comments can be made on the identity of the two unsuccessful
shipments, but the two shipments in 1883 resulting in live fish were the subject
of some confusion. The two shipments resulted in 4,000 to 5,000 fish, some of
which were distributed in the Auckland area and some retained in the Auckland
Domain to form a breeding stock (Ann. Report, A.A.S., 1884). In 1886 some of
the fish retained in the ponds were sexually mature and eggs were obtained from
them (Ann. Report, A.A.S., 1886) but doubts as to their identity were apparent.
In the Minute Book (September 7, 1886) the fish are referred to as "black
spotted Brook Trout". By February 1887 the fish were recognized as rainbow
trout (Minute Book February 1, 1887), and are so identified after this date. The
correction is referred to in Volume VI of the bound annual reports (1931-1938)
and the secretary for that period, T. F. Cheeseman, is credited with the hand
written alterations which appear in the annual reports of the period.

Hugh Craig of San Francisco, an honorary secretary to the Auckland Society,
was instrumental in shipping a variety of plants and animals to Auckland and was
directly involved in the 1883 shipment. Whether he was responsible for the
identification problem is not known.

With this revised identification, the 1883 eggs became the first successful
source of rainbow trout in New Zealand.

Information on the origin of the 1883 shipment was provided in a memoran-



ORIGINS OF NEW ZEALAND RAINBOW TROUT 213

dum dated October 22, 1924 addressed to the Secretary, New Zealand Marine
Department, from L. F. Ayson, Chief Inspector of Fisheries for the Marine De-
partment. Part of this memorandum reads:

"I believe that the first rainbow eggs (so called) were imported by the
Auckland Acclimatisation Society from California about 1877 and two more
small consignments were imported in 1883. These shipments were arranged
for by Mr. Hugh Craig of San Francisco (an ex-New Zealander) and from
inquiries I made on one of my visits to California, I was informed that the eggs
were procured from a private hatchery on the Russian River owned by Mr.
La Motte. Later I visited Mr. La Motte at Ukiah where he was managing a
hatchery for the Great Western Railway Company. In speaking about rainbow
trout in New Zealand, he stated that at the hatchery on the Russian River he
handled only steelhead trout and the eggs he supplied to Mr. Craig were from
steelhead trout so that the first so-called rainbow trout which were liberated
in streams in the Auckland district, including those in the Rotorua and Taupo
Districts, were hatched from these eggs."

Ayson's memorandum gave rise to the often held belief that the source of the
1883 shipments was the Russian River. As will be shown later, this was an
incorrect assumption. However, the indication by La Motte that the eggs sup-
plied to Hugh Craig were from steelhead trout is significant and is supported by
later evidence. It also suggests that the eggs were not supplied to Craig as
anything other than from steelhead trout.

The McCloud and Shasta Shipments
In the same memorandum, given in part above, Ayson states that further
shipments of rainbow trout were imported:

"Several shipments of rainbow eggs collected from the McCloud and Shasta
Rivers were brought to New Zealand later, but I cannot say whether any of
the fish hatched from these eggs were liberated in streams in the Auckland
District or not. Some of the later shipments were brought out by the late Mr.
Johnson of Opawa, Christchurch, and from his hatchery there he supplied
eggs of these fish to different Acclimatisation Societies in the South Island. The
South Island Acclimatisation Societies also procured rainbow eggs from the
Auckland Society so that it is impossible to say whether the rainbow trout in
Lake Hawea, Otago, are from eggs received from Auckland or from Mr.
Johnson's stock fish at Opawa."

It should be noted here that there may have been confusion regarding the
McCloud and Shasta rivers. The Baird Station was located near the town of Mt.
Shasta, but not on the Shasta River. It seems likely that any rainbow trout eggs
shipped from Baird Station came from the McCloud River.

Ayson's statement is confirmed in part by G. M. Thomson, a Dunedin natural-
ist who had made a particular study of faunal introductions to New Zealand.Th-
omson (1926, p. 88) states in discussing the origins of rainbow trout:

"In later years, Mr. A. M. Johnson of Opawa, Christchurch, imported some

more ova and the fry were probably distributed mostly in Canterbury."

Johnson maintained a private fish breeding establishment from 1875 to some
time this century but unfortunately no records of his activities are known to exist
(Scott 1964). If Ayson's statement on the origin of this stock can be accepted,



214 CALIFORNIA FISH AND CAME

then it appears that some time after 1883 Johnson was distributing this stock in
the South Island.

The 1930 Shipment

The Annual Reports of the Auckland Acclimatisation Society indicate that a
further successful shipment of rainbow trout eggs was made in 1930. The report
for the year ending March 31, 1930 (Ann. Report, A.A.S. Vol. VI) states:
"Advice has now been received that 100,000 ova derived from the non-
migratory form of rainbow trout from the inland waters of California will be
shipped about April or May. The ova, if received, will be hatched at the
Internal Affairs Department's hatchery at Rotorua."

The shipment is confirmed in an historical survey entitled "The introduction
of rainbow trout" in Volume VI (1931-1938) of the Annual Reports, where it
is stated:

". . . it was not until the rainbow in the Rotorua Lakes were showing signs
of worms in the lining of the stomach that Mr. Ayson imported a consignment
of rainbow eyed-ova together with quinnet ova from California, some of the
rainbow consignment going to the Rotorua hatchery."

Further details of the distribution are given by Ashby (1967) in a history of
the Auckland Acclimatisation Society. On page 124 he states that in the last 3
months of 1930, 75,000 fry were hatched from the California eggs and were
released at Mangatangi (30,000) and in the Waihou River.

It is possible that the remainder of the shipment was sent to Rotorua, but there
is no information on the release of this part of the shipment.

A possible origin for this shipment is indicated in a letter of July 27, 1 936 from
J. O. Snyder, Chief, Bureau of Fish Conservation, California Division of Fish and
Came, to C. Stokell, Canterbury:

"Sometime ago at the request of some New Zealand authorities, I tried to
determine the origin of the trout which were shipped to that country and
found that I could not do it with any degree of certainty. The fish might have
been the descendants of what we may determine are coast steelheads or they
may have been taken from fishes that perhaps never reached the sea, having
been blocked off through some natural or artificial means. For instance, I am
quite certain that the last shipment of fish eggs to New Zealand came from
Lake Almanor, an artificial reservoir now completely separated from the sea."

The date of the letter and the inland location are both consistent with the New
Zealand statements on this shipment, and it is proposed to regard Lake Almanor
as the probable source of the 1930 shipment.

CALIFORNIA RECORDS
As already mentioned, when the origins of foreign rainbow trout populations
are considered in America they are generally assumed to have been the
McCloud River and the old Baird Station. The history of Baird Station is well
known, and the work of Livingston Stone, who operated the station for the U.S.
Bureau of Fisheries, has been described by Stone (1883), Wales (1939), and
Leitritz (1970). At one time there was controversy over the types of rainbow
trout handled at the station which was operated primarily to obtain ova of
chinook salmon. Needham and Behnke ( 1 962 ) consider that ova were obtained



ORIGINS OF NEW ZEALAND RAINBOW TROUT 215

from both migratory and resident forms.

Little or no evidence can be found in U.S. sources to support the Baird Station
as the origin of the New Zealand rainbows. The only mention found was a brief
comment in the U.S. Commissioner's Report (1887) that the New Zealand
fishery is one of the best examples of a Baird Station success. However, this may
well have been a reference to the successful introduction of chinook salmon, the
eggs of which came from the Baird Station. Livingston Stone (First Report to
Commissioners 1872-1873) mentioned that both New Zealand and Australia
had requested rainbow trout ova from the California Acclimatisation Society. No


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