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ICES Journal of
Marine Science
ICES Journal of Marine Science (2014), 71(8), 1993– 1999. doi:10.1093/icesjms/fsu108
Contribution to the Special Issue: ‘Commemorating 100 years since Hjort’s 1914 treatise on
fluctuations in the great fisheries of northern Europe’
Where we have been
Original Article
A sea change: Johan Hjort and the natural fluctuations
in the fish stocks
Vera Schwach*
NIFU, Nordic Institute for Studies in Innovation, Research and Education, Wergelandsveien 7, Oslo, Norway
*Corresponding author: e-mail: [email protected]
Schwach, V. A sea change: Johan Hjort and the natural fluctuations in the fish stocks. – ICES Journal of Marine Science, 71: 1993 –
1999.
Received 19 January 2014; revised 12 May 2014; accepted 23 May 2014; advance access publication 25 June 2014.
That recruitment of juveniles to the stocks of fish is subject to natural variations is considered a scientific truth, if not a truism, in marine science.
However, in 1914, when the zoologist Johan Hjort (1869 –1948) published the notion, it meant a basic change in the understanding of the biology of
the sea fish. A century later, his insight is a topic still at the centre of interest in fish biology. Hjort based his concept largely on investigations of
herring (Clupea harengus) and cod (Gadus morhua) in the North Atlantic. He was the mastermind, but worked with a small group at the
Directorate of Fisheries in Bergen, Norway, and in cooperation with the International Council for the Exploration of the Sea (ICES). The theory
of natural fluctuations prompted an important step from migration thinking to population thinking, and gave the emerging fish biology and
multidisciplinary marine science a theoretical basis. The article aims to explore the set of important facts and reasoned ideas intended to
explain the causes for variations in year classes, and in this the fluctuations in the recruitment to the stocks. It argues that in addition to scientific
factors, economic and political circumstances had an important say in the shaping of the understanding of stock fluctuations. The mere existence of
a theory does not alone account for a breakthrough, and the article draws attention to the acceptance of scientific results.
Keywords: 1914, Bergen, fish biology, fluctuations, history of marine science, Johan Hjort, Norway.
Introduction
The understanding that the recruitment of juveniles to the stocks of
fish is subject to natural variations was published in an ICES publication entitled “Fluctuations in the great fisheries of northern
Europe” (Hjort, 1914; hereafter 1914-theory). The explanation was
mainly based on investigations on herring and gadoids, especially
cod in northern Atlantic waters, stocks to become model species
for fish biology and management. The theory of the varied strength
of the year classes as a cause for natural fluctuations in the stocks was
significant as it laid the base for the present understanding—and in
2014, a century of research to deepen the knowledge of the various,
and active biological and physical factors. The notion provided the
newly founded community of ICES with a much looked-for theoretical foundation in the investigations of the fish. Fish biology was in
formative years a core field in multidisciplinary marine science;
hence, tracing the realization of the 1914-theory also means to contribute to the understanding of the shaping of marine science
# International
before World War II. The concept of natural fluctuations and its background is examined through a biographical lens as the profile of Johan
Hjort—the main intellectual force behind the theory—is drawn.
The zoologist
Hjort’s social background was the, in percentage, small, but influential,
administrative, and political elite of civil servants (embetsstanden;
Myhre, 2008). His father, Johan S. A. Hjort, was a professor of ophthalmology at the National/University hospital (Rikshospitalet), while his
mother came from the Falsen-family, which like the Hjort’s descended
from Denmark, and had moved to Norway to take up positions as civil
servants, merchants, and craftsmen. Johan grew up as the oldest of six
siblings in the small, but rapid expanding capital of Kristiania
(renamed Oslo in 1925). He was intended for a career in medicine,
like his father and grandfather on the paternal side, but was, after 2
years of study, allowed to change to zoology. Until 1905, no complete
academic degree in zoology existed in Norway. Germany was an
Council for the Exploration of the Sea 2014. All rights reserved.
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1994
V. Schwach
winter term started, the student travelled back to Munich, and began,
early in 1892 to work on the graduation thesis. It dealt typically with
marine invertebrates and the question of the early stages of development of the ascidians (sea squirts): the formation of germ layers and
specialization into specific tissues and organs in the family of
Botryllidae, and especially the development of the nerve system. A
sojourn at the station in Naples in spring 1892 complemented the research. Here Hjort worked with fresh material, and felt unlike in
Munich, the pleasure of scientific discussion on an equal footing.
The young man and the sea
Figure 1. Johan Hjort was a well-regarded marine scientist, but also a
controversial Director of Fisheries, known for his somewhat volcanic
temper. “His personality was so powerful and his views so decided that
he was apt to impose them on others, and he was not very receptive of
views that differed from his own. But he was a great figure whom his
colleagues and friends regarded with respect, admiration and affection,
even when they differed from him ”(Russell, 1948). Illustration: Courtesy
of the family Hjort by Harald Hjort.
obvious choice, and a request was sent to the well-known professor in
zoology, Otto Hertwig at Ludwig-Maximillian-University in Munich
(Schwach, 2000: 64–65). The civil servants were influential, but on
average not awealthy social group; only with careful financial planning,
and a scholarship from the University, was Hjort’s education realized
(Hjort, 1891–1904, 1891–1893; Hjort, 1893b). During the years
abroad, the father wrote regularly, providing the son with familiar
and local news—and a century later, historians with a valuable
source to understand Hjort’s pathway to fish biology (Hjort to
Hjort, 1891–1904; Figure 1).
In the 1880–1890s, important changes in life sciences took place,
and the marine environment stood in the forefront. The first marine
zoological/(biological) stations had emerged at Nice, Naples, and
elsewhere, and they became key loci for developmental morphology
and other evolutionary studies. Hjort’s education followed a mainstream programme, in years when the previous preoccupation
with taxonomy, systematics, and morphology shifted towards evolutionary questions. He attended basic courses in the Bavarian inland,
and had to study marine specimens preserved in spirit. In 1891, Hjort
had a desire to spend summer vacation at the marine biological
station in Villefranche-sur-Mer, Nice. The family’s economy did
not allow such an expense, and the son was called upon. Instead of
southern France, he spent the University vacation in Norway, and
sailed to Bergen for a visit to Bergens Museum. Here, Hjort discovered the abundance of marine life at the western coast of Norway, and
the joy of access to fresh material (Schwach, 2000: 65–66). When the
In January 1893, Hjort obtained the doctoral degree in zoology
(Hjort, 1893a, b).
When the 24-year-old zoologist a month later arrived in
Kristiania, he was awaited not only by his family, but also at
Norway’s only University, “Det Kongelige Frederiks Universitet”.
The zoologist and explorer Fridtjof Nansen (1861–1930) was
eager to be relieved from his duty as curator at the Zootomic
Museum (a forerunner of the zoological laboratory), to set sail
with Fram and leave for polar areas. Hjort stepped in for Nansen.
As an adjunct position, he was appointed research fellow for the
sea fisheries (fiskeristipendiat) by the Ministry of the Interior, as
the hitherto fellow Georg Ossian Sars (1837 –1927) no longer
wanted to carry the burden of outdoor work on the fishing
grounds. Sars had been involved almost since 1860, when Norway
as the first country established a commission for scientific fisheries
investigations (Schwach, 2000: 19 –52). To find a successor had not
been an easy task. In 1890, the British professor W. C. McIntosh
noted that the Norwegians were interested in developing a centralized fisheries board, but had not yet identified the suitable man
to direct it (Macintosh, 1890). Hjort took, against the advice of
his father, the position (Hjort, 1891–1904: 3 April 1892). Sars got
assistance, and 3 years later, in 1896, he passed the responsibility
completely on to Hjort. The payment as fisheries fellow was nearly
twice the wage of the curator position (Schwach, 2000: 69), not a
triviality for a man who was about to marry and maintain a family
(Figureido, 2002: 19 –28). But even more than the salary, Hjort
probably was excited by the chance to work in the field—at the
ocean. In general, the association between sport, field studies, and
science was strong among naturalists, and it took a special form in
Scandinavia due to climatic conditions and partly influenced by
the polar researcher’s expeditions and adventures (Schwach, 2000:
69 –70). Natural sciences in Norway were dominated by disciplinary
cultures founded upon fieldwork before 1940. For Hjort, the field
meant the North Atlantic, and “the hazardous work of carrying
on continuous scientific investigations in the storm-swept waters
of the North Sea”, as the American zoologist, Charles A. Kofoid in
1908 summarized his impressions of the ongoing research in
Bergen (Kofoid, 1910: 298). Enthusiasm for outdoor scientific work,
intertwined with solving practical problems of the fisheries, led
marine researchers like Hjort to the sea. Still, 1895–1896, Hjort
went back to Germany for studies in physiological chemistry and
further cell studies, but by 1900, he turned his attention to what
became a lifelong commitment to commercially important fish
and marine species. But, exactly what motivated a young marine zoologist, with promising prospects of a university career, to choose
fish biology, a discipline in its very first beginning, is not known.
With a face turned to the ocean
The Norway Hjort returned to was, with its 2 million inhabitants, a
sparsely populated country, where the majority lived closed by the
shores of thousands of miles of seacoast. The sea and its fish were
1995
Johan Hjort and the natural fluctuations in the fish stocks
of vital importance for the national economy, as especially from
1815 to 1880, a substantial income was gained from extensive maritime trade and export of fish, making surplus capital available,
which again contributed, to reinvestments and domestic growth.
Despite the fishing industry’s declining relative significance from
the 1880s, it remained vital both to the economy and to the population along the long coast. The political recognition of the sea fisheries went hand in hand with the government’s willingness to
modernize, that is, adapt the industry to a capitalistic economy.
The political attention to the fishing industry included also laws
and regulation, public supervision, and economic statistics.
Owing to the importance of the large seasonal catches of cod and
herring for export income, the Norwegian government’s interest
had from 1860 a main point in the migrations of cod and herring;
in this respect, the investigations were very specific. Scientific investigations were considered an appropriate way to establish basic
knowledge of the ocean and its resources. In addition, the scientists
served as strategists for modernization in a primary industry and
occasionally as its implementers. Hjort became the foremost entrepreneur in the history of the Norwegian marine science with his aim
to integrate a scientific with an economic perspective to establish a
scientific discipline, as well as a scientific-based fisheries management and a capitalistic fishing industry (Schwach, 2000: 128–132;
Schwach, 2013). In a national (and Nordic) context, marine
science is one example of a trust in a science-based, instrumental rationality to solve pressing political and economic issues (Sörlin and
Warde, 2007: 124; Asdal, 2011).
A national, Scandinavian, and international
momentum
The Swedish chemist-turned-oceanographer, Otto Pettersson
(1848– 1941), wrote a letter to the newly appointed fellow (Hjort
to Pettersson, 1893–1901, answer of 3 January 1893). In this, he
suggested incorporating surveys on physical and biological properties of the sea, and coordinating the Scandinavian efforts by regular
and agreed short surveys four times a year. Hjort agreed and
joined Pettersson’s programme (Hjort to Pettersson, 1893–1900;
Pettersson to Hjort, 1893–1900; Schwach, 2000: 70 –71). Both
Pettersson and Hjort was among the Scandinavian scientists who
committed themselves to founding ICES in 1902, and Hjort’s
career became linked to the Council in terms of establishing its scientific foundation and building it as an organization.
In the last decades of the 19th century, a desire to understand the
underlying causes of fish distributions and the total amount of fish
in the sea led managers and scientists, whose concerns reflected the
economic importance of the fisheries in their countries, to seek for
ways to organize the public efforts. These efforts would include
both artificial hatching and studies of biological and/or physical
conditions of the seas around the states (Rozwadowski, 2002:
9 –41). ICES combined marine science with the needs for
(a scientific based) management of the fisheries, and was from
1900 to 1940, the principal community for studies of fish, biological,
and physical properties of the ocean (Mills, 1989: 75 –186;
Rozwadowski, 2002: 3). The early programme of ICES’ was an
outcome of the previous Scandinavian surveys, mixed with a widespread concern that humans drew too heavily on the fish stocks,
and thus an urge to investigate the assumed overfishing in the
North Sea and in the Baltic Sea. The Scandinavians, in particular
the Norwegians, did hardly see variations in the catches in terms
of overexploitation. In fact, the fishing resources, especially
Figure 2. Michael Sars was an English trawler rebuilt at Fredrikstad
Mekaniske verkstad, Norway. She was 125 ft long, with a beam of 23 ft,
draught 12 ft, tonnage 226 grt. Michael Sars had a coal-fired steam
engine, 300 hp, but was also rigged for sail. Illustration: Courtesy of
Institute of Marine Research.
herring, were, until 1969, thought of as a horn of plenty and were,
if regulated, only temporarily. Hjort in 1899 stated his motto
“fish more”, an axiom he kept all his life (Dahl and Hjort, 1899:
133–136; Schwach and Hubbard, 2009: 38– 40).
Heading back to Norway
In October 1900, Hjort sailed to Bergen with Michael Sars, the newly
purchased vessel of the Board of the Fisheries (Fiskeristyrelsen) and
Hjort’s most important tool for investigations (Figure 2). He was to
take up a position as leader for the scientific department in the triumvirate of the Board. After a reorganization in 1906, Hjort became
the sole Director at the Directorate of Fisheries (Fiskeridirektoratet;
Schwach, 2000: 89 –92, 98). The establishment of a new national
management was aimed to unify a range of—partly crossing
conflicting—interests within the sea fisheries. A governmental
agency with management and science integrated under one roof
was internationally seen a unique way to run fisheries issue in
1900, but turned out to be profitable for marine science. ICES and
governmental agencies such as laboratories and fisheries boards
with full-time positions for scientists, regular financing, offices,
and research facilities like access to vessels for surveys did more
to shape marine science than singular expeditions and biological
stations.
Bergen was closer to the important fishing districts than the
capital, and in this regard, a natural choice. However, Hjort
imposed a condition for taking up a position in Bergen: the Board
should be a sole organization, independent of Bergens Museum
(Schwach, 2000: 86). This clause however did not hinder him
seeking cooperation when Hjort himself or the fisheries investigations could benefit therefrom. The sojourn in Naples probably
inspired the way Hjort organized his investigations in Bergen: it
was a group of handpicked peers and assistants—a talented group,
but one of inherent instability. With a vengeance, Hjort combined
national and international investigations (Schwach, 2002). In
ICES, the Bergen-group communicated their ongoing research
and learned about work elsewhere. The formal and informal
network undoubtedly strengthened the group in Bergen, as
1996
contact and collaboration was vital to maintain a high scientific standard in applied research, investigations undertaken close
to the immediate needs of the fisheries management. In the
Parliament, the obligations towards ICES were considered a national duty, and served to protect domestic investigations against
attempts to cut down financial support, especially for the costly
maintenance of Michael Sars. Besides, the maritime sphere, including shipping, polar research and marine investigations were
a source of national pride, fields where Norway could and
should shine.
Migrations gave way to natural fluctuations
and populations
From the 1880s to 1930, a gradual shift from “migration thinking” to
“population thinking” took place in the discipline emerged as fish
biology (Sinclair and Smith, 2002: 297 –304; Smith, 1994). The
notion of migration was developed for herring and by analogy
applied to cod (Hjort, 1914: 2 – 5). Hjort with his 1914-theory
played an important part in the shift. The novelty of Hjort’s scientific
programme lay in its field studies—a broad approach to solve the
enigma of the large variations in the fishing catches: the combination of physical oceanography, biological oceanography, and fish
biology. In fish biology, surveys of all stages of fish: eggs and
larvae, pelagic and demersal juveniles and adults were of importance
(Sætersdal, 2009: 19). Focus in this section are single factors that
had a particular play in providing a fertile ground for the shaping
of the 1914-theory, and will include the issues of hatching cod, a
method to distinguish the schools of herring, and demographical
statistics.
Hatching, a local issue with overarching scientific
consequences
Hatching was 1880–1914, especially in the Anglo-Saxon countries, a
widespread way to improve and secure a stable recruitment of fishing
resources (Cadigan, 2009: 76–80; Schwach, 1999: 27–28). In
Norway, the Flødevigen hatchery (Flødevigen Udklækningsanstalt)
was built in 1884 nearby the town of Arendal, and formally a
branch of the semi-private Society for Development of the
Norwegian Fishing Industry (Selskabet for De Norske Fiskeriers
Fremme). The hatchery was for a large part financed by local
funding. During the days of sailing, Arendal was a prosperous town
owing its wealth to the shipbuilding yards, and local surplus capital
was available. Gunder M. Dannevig (1841–1911) was a driving
force; the methods and technical solutions at Flødevigen including
the hatching tanks seem to have been the foremost of their kind
(Kofoid, 1910: 296–297). Alas, Arendal’s wealth ended abruptly in
1886 due to a profound technological change: steam surpassed sail.
Private revenues disappeared, and Flødevigen became depended
upon public funding. The Parliament decided to evaluate the economic benefits of hatching. Reliable fish statistics was non-existent;
so the parliament suggested to mark the larvae, and set aside
funding for a marking experiment. The task was handed over to
Hjort who asserted that it was impossible to mark newly hatched
larvae; thus, an eventual gain of artificial hatching vs. natural production could not be measured (Stortingsforhandlinger, 1895). Hjort
wrote to one of the very few experts in fish biology at the time, the
Dane C. G. Joh. Petersen (1860–1928), asking him for advice in
this debated issue. Petersen answered by stating his skeptics to the usefulness of hatching (Petersen to Hjort, 1896–1927, 26 February
1895). A fortunate sequel of the question was that Petersen became
V. Schwach
Hjort’s first teacher in fish biology, soon turned to sparring partner
(Petersen to Hjort, 1896–1927).
In 1899, Hjort pointed out that it was not possible to keep the
larvae alive after the first stage when they fed on the content of the
yolk sac. The death rate became extremely high at hatching stations
in both the United States and Norway (Dahl and Hjort, 1899: 141).
The statement was underpinned by referring to Sars’ observations
on the high death rate among yolk sac cod larvae (Sars, 1879: 27).
Dannevig did not give up his mission. In 1900–1902, he represented
the county in the Fisheries Council (Fiskerirådet)—an advisory
council to the Board of Fisheries. At the meeting, he proposed to
count the numbers of larvae (0-group) in fiords where larvae were
hatched and released, and compare the numbers with fiords with
no release of cod larvae. Hjort’s assistant, Knut Dahl (1871–1951)
an outspoken opponent of hatching was put on the task and
counted the number of larvae in 1903, 1904, and 1905 (Schwach,
1999: 40–41). Not surprisingly, Dannevig and Dahl’s findings were
diametrically opposed; but important for Hjort was Dahl’s observation that in years rich in fry, the large numbers were common to a
long stretch of the coast, while in years with few fry; the poverty of
numbers was demonstrated in all fiords (Dannevig, and Dahl,
1906). According to the concept of migration, all the cod in Danish
and Norwegian waters belonged to one sea stock migrating over
large areas (Dahl and Hjort, 1899: 53–54). Around 1904–1906,
Hjort may have started drifting away from the view that migrations
were the essential point to comprehend the variations in recruitment
from year to year. The difference between small and large annual
classes of larvae could it affect the catchable stock?
Herring with a certificate of birth and population
At the inaugural ICES-meeting, three committees were set up. Hjort
was elected “convener” of the Committee A—“the migrationcommittee” (Schwach, 2000: 148 –149). The large fisheries after
cod were a typical feature for Norway, whereas the herring was a
natural resource important in the majority of the membercountries. In 1905, Hjort decided to continue studies on cod, but
also intensify the herring investigations at home and in the
“migration-committee”. He saw it as an opportunity to concentrate
the work on joint species, strengthen the ICES-community, and
convince, in the many countries hesitant managers, about the practical value of the fisheries investigations. The omnipresent
Pettersson agreed (Pettersson to Hjort, 1894–1939, 15 February
1905; Schwach, 2000: 155). This way cod and European plaice
(Pleuronectes platessa) but foremost herring in an early phase
became model species for fish biology (Stephenson and Clark, 2002).
Friedrich Heincke (1852– 1929) at the German scientific
commission (Die Deutsche wissenschaftliche Kommission für
Meeresforschung) and member of the “migration-committee”,
had after 20 years of measuring meticulously herrings from different
waters, reached the conclusion that herring comprise geographically
distinct spawning stocks (Heincke, 1898). First, using Heincke’s
method, Hjort and assistants classified the spawning populations
in “Norwegian waters” (Hjort to Heincke, 1902–1911; Schwach,
2000: 141– 144). The age of the herring was decided customary by
measuring its length (Hjort, 1914: 16 –18). Heincke’s procedure
to distinguish the herring stocks was very time-consuming, a
serious disadvantage in Bergen where the men were few and the
ocean large. The herring in barrels waiting to be measured decomposed, and due to the smell and complaints from the neighbours,
the scientists were forced to remove the barrels (Koefoed and
Broch, 1962: 28; Schwach, 2000: 148–152). One can easily assume
1997
Johan Hjort and the natural fluctuations in the fish stocks
that Hjort was stressed by the situation. In 1904, Hjort remembered a technique of age determination in fish by scales and otoliths, brought to his knowledge by German peers 4 years earlier,
but of which he then had not taken notice (Hensen to Hjort,
1900, 5 December 1900; Heincke to Hjort, 1902 – 1907, 12
December 1903). Could the scales or otoliths of herring give any
useful information about size/age, growth, and spawning? He
found it worth trying, and let a young assistant, Hjalmar Broch
(1882 – 1969); Broch, (1906) and later Dahl (1907) tests this
method. Broch showed that the scale was an adequate means to a
precise determination of the age and of growth patterns of the
herring. He also proved systematic differences in the growth rate
between different spawning populations. Einar Lea (1887 – 1969)
refined the methods and technique (Schwach, 2000: 152 – 159,
166 – 167). Heincke’s method was set aside; from 1907, the herring’s growth zones, in particular the winter rings were used to determine the age, growth, and which spawning stock the single fish
belonged to (Hjort, 1914: 18 – 21). The investigation in 1908
revealed that the herring did not reproduce evenly, rather large variations from one year to another was the norm. Herring from 1904
was overrepresented of all the herring caught and counted. The
next year, in 1909, this year class added up to 77% of the total.
The nature yielded a large year class in 1904—a generous gift to
the fish biologists (Schwach, 2000: 159 – 160).
Widows, orphans, and the population of herring
An incidental linking between natural science and an expressed need
for a social reform became another turning point for the fish biologists in Bergen. Hjort was first introduced to (descriptive) statistics
through Heincke’s work, and in practice by a report to the
Parliament on mandatory insurance for fishers (Schwach, 2000:
157–158). In their application of statistics and biometrical
methods, the Bergen-group was in vogue in zoology. The local backdrop was a terrible disaster at sea offshore of Titran, a fishing village on
Frøya, in the county of Nord-Trøndelag. On a stormy night in 1899,
120 fishers lost their lives, leaving behind widows and children in
poverty. In autumn 1906, Hjort, in the capacity as Director, was
requested to head a public committee, and write a proposal on accident and death insurance for fishers (Stortingsforhandlinger, 1907–
1908; Norsk Fiskeritidende, 1907: 135). Parallel initiative was taken
for other groups of workers, in years before pensions, death and compensation insurances were coordinated and made general (i.e. The
National Insurance Scheme, 1967; Seip, 1984: 174–175). In writing
the proposal, Hjort cooperated with the renowned actuary Andor
Hoel, from 1908 the first director of the public service pensions
fund in the municipality of Bergen (Bergens kommunale pensjonskasse; Sollied, 1932). During the work, Hjort was exposed to demographic statistics, a field in which domestic statisticians had gained
a good knowledge (Lie and Roll-Hansen, 2001). To stipulate the
cost of the insurance premiums to be paid by the single fishers to compensate—economically—for the loss of income, the actuary calculated the numbers and structure of the population of the fishers
and their families. The estimations included the age composition of
all men recorded in the national census as fishers, estimations of
birth and death, and the average number of children in the group.
Hjort noticed that the year classes in the fishing population were
not of equal size, and the population pyramid changed over time. It
struck him that the methodology of demography might be useful to
understand the patterns of the fish stocks: “As I [Hjort] was occupied
with the question about an accidental insurance for the fishermen, it occurred to me that one could gain deeper substantial and
deeper understanding also of the fish stocks by examining the age
compositions in the various herring stocks ” (Hjort, 1911).
Consequently, Hjort transferred his newly gained knowledge to the
population of fish. At this point, the position as Director of
Fisheries, with the responsibility for the national statistics of the fisheries, and employees with experience in collecting statistics, certainly
was no disadvantage (Nordstrand, 2000). For the fisheries, Hjort
assumed a linkage between the amount of fishers’ catches and the
sizes of the year classes, in that a rich annual class will affect the
adult, catchable stock.
The last, critical stage
Hjort’s work was met with critics in ICES. British (marine) zoologists, in ICES foremost represented by Wentworth D’ Arcy
Thompson (1860 –1948), had taken an interest in biometrics.
Hjort and Thompson over herring scales collided in 1910 (RP, XI,
part B, app. D, 1909: 64 –66). The dispute ended only in 1938
(Schwach, 2000: 171– 176). Hjort asserted that the rings on
herring scale reflected precisely the age/years of the herring, the
counting winter rings being a core in research programme in
Bergen. Thompson claimed that the age-determination of herring
was inexact (RP, XIX, part B, app. D, 1913: 102–104). He also
believed that scale rings were a physical—optical—phenomenon
only. In retrospect, the advantage of the controversy was the
demand felt in Bergen to elucidate the method for counting the
winter rings of ageing on the scale and its technique. Another
point of critics seems to have been that Hjort ran the committee A
as a branch of the Norwegian investigations, and that the publications of the committee’s report exceeded the budget (Schwach,
2000: 165). In 1909, ICES’ structure was changed, and the three
initial committees were discontinued (Rozwadowski, 2002: 52 –
53). Hjort was offered a small sum to continue the investigations
on herring-scales. The scientific results to be presented as the
“Fluctuations in the Great Fisheries of Northern Europe” were, in
its concluding phase, much of a national project (Schwach, 2000:
164–170). By 1909, Hjort probably had a hunch that he was on a
track worth following: the cause of the fluctuations in the spring
herring fishery was the success or failure of the year classes composing
the stocks. Additional surveys supported his view: Bjørn HellandHansen (1877–1957) investigated haddock (Melanogrammus aeglefinus) in the North Sea (Helland-Hansen, 1909), Désiré Damas
(1877–1957) examined cod and other gadoids’ eggs in the northern
Atlantic 1900–1906 (Damas, 1909), and Dahl reported yearly variations in the North Sea (Dahl, 1909; Sinclair and Smith, 2002: 300–
302). Hjort likely became certain of variations in the annual classes
of herring and gadoids, and sometimes between 1910 and 1913, he
first formulated the hypothesis that the larval stage was of paramount
importance for the size of a year’s class. He discussed whether either
predators ate the eggs and/or the possibility that physical conditions
such as the temperature of the water or its salt content were decisive
for the size of a year’s class. Hjort believed that to survive a critical
stage, it was essential that the larvae had sufficient food (Hjort, 1914:
202–207).
Presentation, war, and acceptance
The 1914-theory in its entirety was presented in an evening lecture
on 16 September 1913 in Copenhagen, during the annual
ICES-meeting (RP, 1913. XIX, part B; app. D, 102; RP, 1915. XXI,
part B, 16 –20). In spring 1914, the publication was printed:
volume XX of the ICES’, “Rapports et Procès-Verbaux” (Hjort,
1914). At the same 1913-meeting, a herring committee was set up
1998
V. Schwach
Conclusion: fluctuations in fish biology
Figure 3. Johan Hjort, photo presumably taken during the Canadian
fisheries expedition, 1914/1915. “Hjort was always happy in a ship”,
stated his long time British colleague H. G. Maurice in an obituary
(Maurice, 1948). Illustration: private, Vera Schwach (photographer
not known).
(RP, 1913. XIX, part B, annex A, 60). By May 1914, and after an
excursion to the spring herring districts on the west coast of
Norway to investigate and agree upon the methods and standards
for sampling, the committee drew up a plan for investigations in
the ICES-member countries. The plan embraced both fish biology
and “hydrographical observations”, and it reflected the two overarching issues in fish biology: overexploitation and/or natural fluctuations of the natural resources of fish (RP, 1915. XXI, part B, 1915:
16 –20).
Dark skies covered Europe, and in July, World War I broke out
and interfered with ICES including the joint herring investigations.
The warfare forced ICES to keep its activity at a minimum and
hampered the distribution of the 1914-theory. By 1918, the situation
had changed. In 1914, the military requisitioned Michael Sars to
safeguard Norwegian neutrality. In 1917, owing to an argument
with the Norwegian government about neutrality and fishing
exports to the United Kingdom, Hjort resigned and left Bergen.
Germany withdrew from the ICES in 1915 and only returned in
1926 (Went, 1972: 51, 68), giving the United Kingdom a larger influence in the ICES. Only in 1929 and 1930 was Bergen’s method
and results from 1914 accepted fully in the ICES (Sætersdal, 2009:
25 –26).
Johan Hjort was a highly qualified and promising marine zoologist
who linked the new developmental marine zoology with the emerging fish biology. Hjort should be noted for his ability to transformed economic and political problems into research questions,
his daring in formulating risky hypotheses, a groundbreaking
theory, and the ability to convert scientific knowledge for the use
of management of the sea and its marine resources. He was politically shaped by, and worked in a domestic and international situation
that favoured scientists who offered both a basic and practical mode
of pursuing scientific investigations. The work in Bergen is one early
example of how governmental agency with full-time positions for
scientists, regular financing, offices, and facilities such as vessels
for surveys did shape modern marine science. Culturally seen,
Hjort was part of a disciplinary culture dominated by work in the
field. The willingness to work onboard the research vessel and
make cruises in all seasons and weather conditions of the year was a
premise for Bergen’s broad approach to marine research (Figure 3).
The 1914-theory was a possible, in no way predetermined outcome
of investigations on fish and the ocean in Norway and Scandinavia
since 1860, and in ICES after 1900.
The novelty of Hjort’s scientific programme lay in its field
studies—a broad scientific approach to solve the enigma of the
large variations in the fishing catches, combined with specific economic and pressing research questions. While fisheries researchers
tended to focus on the fishable stock, Hjort partly owing to his academic training, the work of the predecessor G.O. Sars, and a controversy over hatching, came to focus on the early stages of the life cycles
of fish. In addition to hatching, a method to distinguish the schools
of herring, and demographical statistics played a prominent role.
From the understanding of the awareness of natural variations
between different year classes and the larva stage as critical for the
size of an individual year’s class arose the notion of the natural fluctuations in fishing stocks and the question of the significance of the
early “critical stage”.
World War I discontinued the research, which had constituted
Bergen as a centre of fish biology. The mastermind had disappeared,
and in the remaining researchers, there were hardly anyone with the
same intellectual capacity and political influence. The ocean-going
vessel, the most important tool—essential to undertake surveys of
the highly migratory fishing stocks of cod and herring in the
North Atlantic—was gone. Differences in the economic and scientific interests of Norway and most of the ICES members may also
explain the loss of Bergen’s leading position. After 1918, the attention of fish biologists in “North Sea-countries”, under the leadership
of the UK, was directed towards investigations of the commercially
important stocks of ground fish, and the presumably overexploitation of the stocks.
Acknowledgements
I thank the referee Mike Sinclair and the editor for their most useful
comments and critical questions.
References
Asdal, K. 2011. Politikkens natur og naturens politick. Universitetsforlaget,
Oslo.
Broch, H. 1906. Foreløbige meddelelser om sildeundersøgelserne.
Årsberetning for norske fiskerier, 1905: 442– 451.
Cadigan, S. 2009. Science, industry, and fisheries in fisheries management: the experience of Newfoundland and Labrador, 1890s–
1990s. Studia Atlantica, 13: 75 – 92.
Johan Hjort and the natural fluctuations in the fish stocks
Dahl, K. 1907. The scales of the herring as a means of determining
age, growth, and migrations. Fiskeridirektoratets skrifter, serie
havundersøkelser, II: 1 – 36.
Dahl, K. 1909. The assessment of age and growth in Fish. A short account
of the development of present methods and main literature on the
subject, Internationale Revue der gesamten Hydrobiologie und
Hydrographie 2: 758 – 769.
Dahl, K., and Hjort, J. 1899. Fiskeforsøg i Norske fjorde. Kristiania.
Damas, D. 1909. Torskefiskene (Gadidæ), Report on Norwegian Fishery
and Marine Investigations, II, part 1.
Dannevig, G. M., and Dahl, K. 1906. Undersøgelser over Nytten af
torskeudklækning i Østlandske fjorde, 1. Betænkning afgiven af
Knut Dahl; 2. Betænkning afgiven av G.M. Dannevig; 3. Bilag
I. Undersøgelser og forsøg foretagne i fællesskab af Knut Dahl og
G.M.Dannevig; 4. Bilag II. Undersøgelser og forsøg udførte af K.D.
Aarsberetning vedkommende Norges Fiskerier for 1906, Bergen:
1 – 121 + bilag.
Figureido, I. 2002. Fri mann. Johan Bernhard Hjort—en dannelseshistorie. Aschehoug et co., Oslo.
Heincke, F. 1898. Naturgeschichte des Herings I. Die Lokalformen und
die Wanderungen des Herings in den europäischen Meeren.
Abhandlungen des Deutschen Seefischerei-Verein, bd.II, Berlin.
Heincke, F., to Hjort, J. 1902 –1907. The National Library of Norway.
Johan Hjort’s collection of manuscripts, file number 2911, 40,
XIXA (hereafter NB, ms. 2911), 17 letters.
Helland-Hansen, B. 1909. Statistical research into the biology of the
haddock and cod in the North Sea. Rapports et Procès-Verbaux
des Réunions du Conseil International pour l’Exploration de la
Mer (hereafter RP), X: 3 – 62.
Hensen, V., to Hjort, J. 1900. NB, ms. 2911, 40 XIXA, 15.12.1900.
Hjort, J. 1893a. Über den Entwicklungscyclus der zusammengesetzten
Ascidien. Inaugural Dissertation zur Erlangung der Doctorwürde
vorgelegt der hohen philosophischen Facultät, II. Section der
Ludwig-Maximillians Universität zu München, Leipzig, 32 pp.
Hjort, J. 1893b. The National Archives (of Norway). Universitetet i Oslo,
katalog. 1993, kat. Nr. 1251/3.10, J. Hjort to Det akademiske kollegium, 14.04.1896.
Hjort, J. 1911. Befolkningslærens Methoder i Fiskeriundersøgelserne.
Sildefiskeriernes Vexlinger (Offprint of Bergens Aftenblad, 2.5.1911).
Hjort, J. 1914. Fluctuations in the great fisheries of northern Europe
viewed in the light of biological research. RP, XX, Copenhagen.
Hjort, J., to Heincke, F. 1902– 1911. The Regional State Archives in
Bergen, The Archive of the Directorate of the Fisheries, archival
numbers, 212/1-5 and 211/1, 17 letters.
Hjort, J., to Pettersson, O. 1893 – 1905. The University Library of
Gothenburg, Sweden, AccH 1985:25, 64 letters.
Hjort, J. S. A., to Hjort, J. 1891 – 1904. Private collection of the letter kept
by the family Hjort, att. Harald Hjort, Oslo, Norway, 85 letters.
Koefoed, E., and Broch, H. 1962. Mennene i “den gamle garde”. In Havet
og våre fiskere, bd. II, pp. 21 – 29. Ed. by G. J. W. Rollefsen. Eides
forlag, Bergen.
Kofoid, C. A. 1910. The Biological Stations of Europe. Bulletin/United
States Bureau of Education, no. 4, Washington.
Lie, E., and Roll-Hansen, H. 2001. Faktisk talt: statistikkens historie i
Norge. Universitetsforlaget, Oslo.
Macintosh, W. C. 1890. The administration of foreign fisheries. Nature,
41: 497 –500.
Maurice, H. G. 1948. Prof. Johan Hjort, For. Mem. R. S. Nature, Nov. 13,
765– 766.
Mills, E. L. 1989. Biological Oceanography. An Early History, 1870 –
1960. Cornell University Press, Ithaca and London.
1999
Myhre, J. E. 2008. Academics as the ruling elite in the 19th century
Norway. Historical Social Research, 33: 21– 41.
Nordstrand, L. 2000. Fiskeridirektøren melder. Fiskeridirektoratet,
Bergen.
Norsk Fiskeritidende. 1907.
Petersen, C.G. J., to Hjort, J. 1896– 1927. NB, ms. 2911, XIXA, 91 letters.
Pettersson, O., to Hjort, J. 1894– 1939. NB, ms. 2911, XIXA, 234 letters.
Rozwadowski, H. 2002. The Sea Knows No Boundaries. A Century of
Marine Science under ICES. International Council for the
Exploration of the Sea/University of Washington Press, Seattle
and London.
RP. 1909. XI, Rapports administrafis etc., Copenhague, June 1909.
RP. 1913. XIX, Rapports administrafis etc., Copenhague, Septembre
1913.
RP. 1915. XXI, Rapports administrafis etc., Copenhague, June 1915.
Russell, E. S. 1948. Prof. Johan Hjort, For. Mem. R.S. Nature, Nov. 13,
764– 765.
Sætersdal, G. 2009. From fisheries research to fisheries science, 1900–
1940: tracing the footsteps of Johan Hjort in Bergen and the ICES.
In 2008. Norwegian Spring-spawning Herring & Northeast Arctic
Cod. 100 Years of Research and Management, pp. 17– 32. Ed. by
O. Nakken. Tapir Academic Press, Trondheim.
Sars, G. O. 1879. Indberetninger til Departementet for det Indre fra
Cand. G.O. Sars om de af ham i Aarene 1864– 79 anstillede praktiskvidenskabelige Undersøgelser angaaende Saltvandsfiskerierne,
Christiania.
Schwach, V. 1999. The impact of artificial hatching of cod on marine research. Historisch-meereskundliches Jahrbuch, 5: 27– 47.
Schwach, V. 2000. Havet, fisken og vitenskapen. Fra fiskeriundersøkelser
til et havforskningsinstitutt. Havforskningsinstituttet, Bergen.
Schwach, V. 2002. Internationalist and Norwegian at the same time:
Johan Hjort and ICES. ICES Marine Science Symposia, 215: 39– 44.
Schwach, V. 2013. The Sea around Norway: science, resource management and Environmental concerns in Norway, 1860– 1970.
Environmental History, 18/1: 101– 110.
Schwach, V., and Hubbard, J. M. 2009. Johan Hjort and the birth of fisheries biology: the construction and transfer of knowledge,
approaches and attitudes, Norway and Canada 1890 –1920. Studia
Atlantica, 13: 20 – 39.
Seip, A-L. 1984. Sosialhjelpstaten blir til. Norsk sosialpolitikk 1740 –
1920. Gyldendal, Oslo.
Sinclair, M., and Smith, T. 2002. The notion that fish forms stocks. ICES
Marine Science Symposia, 215: 297– 304.
Smith, T. 1994. Scaling Fisheries. The Science of Measuring the Effects of
Fishing 1855– 1955. Cambridge University Press, Cambridge.
Sollied, P. R. 1932. Hoel, Ole Andor. Norsk biografisk leksikon, X:
159– 163.
Sörlin, S., and Warde, P. 2007. The problem of the problem of environmental history: a re-reading of the field. Environmental History, 12:
107– 130.
Stephenson, R. L., and Clark, K. J. 2002. The role of ICES herring investigations in shaping fisheries science and management. ICES Marine
Science Symposia, 215: 504 – 514.
Stortingsforhandlinger. 1895. bd.1, St.prp. No.1, Hovedpost VI, kap.5,
bilag nr. 18, 19.
Stortingsforhandlinger. 1907– 1908. bd. 3, Odelstingsproposisjon nr.
10, aangaaende udfærdigelse af lov om forandring af lov om ulykkesforsikring for fiskere.
Went, A. E. J. 1972. Seventy years agrowing. A history of the
International Council for the Exploration of the Sea, RP. 165,
Copenhagen.
Handling editor: Carmel Finley