Biology in History
780 BioScience • September 2005 / Vol. 55 No. 9
Most ecologists and evolutionary biologists are
familiar with the saga of the introduced Nile perch
(Lates niloticus) in Lake Victoria. The explosion of the lake’s
Nile perch population in the 1980s was monitored closely, be-
cause it coincided both with a fivefold increase in the economic
value of the fishery (Reynolds et al.1995) and with a halving
of the lake’s 500-species haplochromine cichlid flock (Ogutu-
Ohwayo 1990).This reduction in species and functional di-
versity restructured the lake’s ecology; for example, the
disappearance of zooplanktivorous haplochromines coin-
cided with a dramatic sixfold increase in biomass of the zoo-
planktivorous cyprinid Rastrineobola argentea (Wanink 1999).
By the early 1990s, what had been a diverse multispecies
fishery rested on only three species: the nonindigenous Nile
perch, the nonindigenous Nile tilapia Oreochromis niloticus,
and the diminutive R. argentea. Although some of the blame
for the cichlid extinction spasm has been shifted from the Nile
perch to other anthropogenic factors, such as overfishing
and eutrophication (Seehausen et al. 1997), the Nile perch was
certainly a major contributor.
The lucrative fishery that developed for Nile perch has it-
self had diverse impacts. Around the lakeshore, enthusiasm
over the increase in the value of the fishery has been tempered
by concerns about species loss, increased economic stratifi-
cation, and the fact that most Nile perch is exported and lo-
cally unaffordable (Pringle 2005). Ecologically, the intense
fishing pressure on Nile perch has depressed its populations
to the extent that certain species of the remnant cichlid fauna
are resurging (Witte et al. 2000).
These events have spawned hundreds of publications,
making the Nile perch in Lake Victoria one of the best-
studied invasive species in history (for a recent review, see
Balirwa et al. 2003).Yet despite this wealth of knowledge,there
remains confusion about exactly when, why, and by whom the
Nile perch was introduced into Lake Victoria. The literature
offers a range of dates for the introduction, from the 1920s
to the 1960s; tracing the tortuous citation chain to the origins
of these dates reveals a fundamental uncertainty about when
the Nile perch was first introduced.Likewise, the motivations
for this anthropogenic introduction, often ambiguously as-
cribed to a desire to “increase productivity,” have not been
Unlike many introductions , which occur b y acc ident o r are
made quietly by private citizens, the introduction of Nile
perch into Lake Victoria was hotly debated at the highest
levels of the British administration in colonial East Africa. As
today’s ecologists often note, colonial ecologists opposed the
proposal (Fryer 1960).The eventual introduction of the Nile
perch therefore represents the failure of ecologists to com-
municate and implement their vision for Lake Victoria.
Although this failure was at least partially due to the famil-
iar problem of trying to regulate a common resource, I
suggest that there were two additional factors at play.
Robert M. Pr ingle (e-mail: firstname.lastname@example.org u) was a Thouron Fellow in
the program in Economic and Social History at the University of Oxford
when this research was conducted; he is now a doctoral student in the
Department of Biological Sciences at Stanford University, Stanford,CA 94305.
Althou gh his cur rent focus is tropica l ecology (esp ecially of Afri can savannas),
he maintains an active interest in history and its applications to ecology and
environmental policy. © 2005 American Institute of Biological Sciences.
The Origins of the Nile
Perch in Lake Victoria
ROBERT M. PRINGLE
The ways in which economic, social, and political forces lead to species introductions are an important, if overlooked, aspect of ecology and
conservation. The nonnative Nile perch (Lates niloticus) in Lake Victoria, and the ecological changes associated with the species’ establishment and
expansion there, has elicited tremendous attention from biologists. Yet it has never been clear why, when, or by whom the fish was introduced. Here
I outline the history of fishery research and management in East Africa and explore the circumstances that led to the introduction of the Nile perch.
The evidence suggests that repeated secretive introductions were made in the mid-1950s by members of the Uganda Game and Fisheries Department
as part of a bifurcated effort to improve sport fishing on the one hand and to bolster fisheries on the other. Fisheries scientists affiliated with the East
African Fisheries Research Organization opposed the introduction, but were ineffective; I suggest that this failure stemmed partially from their
inability to engage effectively with political processes.
Key wo rds : A fri can c ich li ds, exo tic s pec ie s i ntr od uct ion s, ex ti nct ion , i nv asi ve spe ci es, Haplochromis
September 2005 / Vol. 55 No. 9 • BioScience 781
The first of these factors stems from the nature of British
colonialism in East Africa and the role of science within it. The
colonial enterprise underwent a transformation in the late
1930s. The Great Depression had highlighted human vul-
nerability and prompted new concern for the welfare of
Britain’s “dependents” in the colonies. Likewise, confrontation
with Nazi Germany had made clear,among other things, the
true ugliness of imperialism. Hence the shift to what histo-
rians have called “the second colonial occupation”(Low and
Lonsdale 1976): the paternalistic attempt to guide Africa
through development and into modernity,in which eventual
self-government was a stated aim.But administrators in this
new developmental bureaucracy lacked the patience of their
predecessors for basic ecological research. They wanted im-
mediate results, practical scientific means of running an ef-
ficient transitional empire. The scientists who opposed the
introduction of the Nile perch into Lake Victoria failed to en-
gage effectively with these emergent political trends; as a re-
sult, they were considered too cautious and their research too
pure. They were thus kept to the political margins,where they
found it difficult to influence policy.
The second factor relates to the history of ecology and
evolutionary biology as disciplines. The late 1950s and 1960s
were a particularly fertile time for ecological and evolution-
ary ideas; several conceptual developments of that period
would arguably have enabled fisheries scientists in East Africa
to make a more forceful case against the Nile perch intro-
duction, had the debate taken place a few years later than it
Whether or not it was “right” to introduce the Nile perch
into Lake Victoria is a contentious and subjective question
(Pringle 2005). I do not wish to take a stand on that issue here.
Neither am I interested in apportioning blame—or credit—
for the Nile perch’s introduction, the haplochromine extinc-
tions, or the economic growth of Lake Victoria’s fisheries. My
only intention is to shed light on the social, economic, sci-
entific, and political processes that led to these important
events.Thus, although I speak of the “failure”of scientists to
prevent the introduction,I do not mean it in a pejorative sense.
It was simply the failure of a stated objective.
The origins of fishery research and
To t h e B r i t i s h i n E a s t A f r i c a , L a k e V i c t o r i a ’ s 7 0 , 0 0 0 s q u a r e k i l o -
meters (km2) seemed capable of supporting outstanding
fisheries. The 1901 completion of the railroad from Mombasa
to Kisumu, which enabled the transport of lake fish to Nairobi
marketplaces, provided an added incentive to maximize fish-
ery production.Yet by 1921 there was concern that fish yields,
especially of ngege (Oreochromis esculentus), were declining.
One observer,assistant surgeon E. J. H. Oorloff, complained
that Africans were overfishing the lake with the aid of imported
equipment—“the better class of natives use English nets”—
and recommended that a closed season be implemented
(Oorloff 1921). However, administrators were hesitant to
regulate fishing, principally because their ignorance of fish
biology left them unsure whether “any good results would
accrue from putting fishermen to the hardship of a general
close season” (Caldwell 1923); it was suggested that museum
experts be recruited to survey “the finny denizens of our
premier pool” (Anonymous 1923).
To t h a t e n d , M i c h a e l G r a h a m a n d E d g a r B a r t o n W o r -
thington traveled from Britain in 1927 and spent a year
steaming around Lake Victoria. Their work resulted in Gra-
ham’s (1929) The Victoria Nyanza and Its Fisheries. In that
book, Graham recommended that a permanent fisheries re-
search institute be erected to continue scientific study of the
lake. This led to the construction in 1947 of a research labo-
ratory in Jinja, Uganda, which became home to the East
African Fisheries Research Organization (EAFRO). Crucially,
however, an earlier warning by Worthington—that “it would
be a mistake to separate administration from research in the
matter of fisheries” (Worthington 1940)—was ignored. “I
suppose difficulties are bound to go on,” Worthington had
written,“so long as fisheries in Uganda are directly under the
Game Department, while in Kenya they are ? [sic] Agriculture,
and in Tanganyika are directly under the Administration”
(Worthington 1940). Ultimately, however, research and ad-
ministration were indeed separated; the Lake Victoria Fish-
eries Service was created as an interterritorial administrative
body distinct from EAFRO in 1948.
In 1950, the East African High Commission implemented
the Lake Victoria Fisheries Act.The act initiated several con-
servation measures, one of which was the stricture that “any
person who introduces, puts or places into Lake Victoria any
fish, or the spawn thereof, of a species other than that in
Lake Victoria...shall be guilty of an offense against this Act.”
Significantly,EAFRO and Lake Victoria Fisheries Service per-
sonnel were exempt from these provisions. And although a
1953 amendment to the 1950 act extended its legislative
reach one mile up “each river and stream entering Lake Vic-
toria,” the rest of East Africa’s inland water remained under
These provisions reflected a growing debate over whether
fishery productivity might be increased by introducing non-
indigenous species into Lake Victoria. Colonial officials were
frustrated that Africa’s largest lake contained relatively small
fish, mostly cichlids of the genus Haplochromis. Hap-
lochromine cichlids were widely utilized by local fishermen,
but the British disdained them, labeling them “trash fish.”In
The Victoria Nyanza and Its Fisheries, Graham (1929) wrote,
“It has been suggested to me frequently that Lake Victoria
would be improved if its fish fauna contained some of the Lake
Albert species, such as the Nile perch (Lates) or the Tiger fish
(Hydrocyon)” (p. 23). Graham conceded that this was a rea-
sonable idea, but he urged caution: “In the ngege fishery of Lake
Victoria we have an extremely valuable established fisher y for
a very desirable fish. The introduction of a large predatory
species from another area would be attended with the utmost
danger,unless preceded by extensive research into the prob-
able effects of the operation” (Graham 1929, p. 23).
Biology in History
Biology in History
782 BioScience • September 2005 / Vol. 55 No. 9
Of course, the introduction of nonindigenous fish was a
common practice in colonial East Africa. Beginning in the
1890s, colonial administrators stocked dozens of Kenya’s
rivers with trout, both to entertain themselves and to entice
prospective settlers.Later, in an attempt to stem tilapia declines,
EAFRO blessed the introduction of four nonindigenous
tilapiines (Oreochromis leucostictus, O. niloticus, Tilapia ren-
dalli, and Tilapia zillii) in 1953. Although legal under the
1950 Fisheries Act’s exemption of fisheries officials, these
tilapia introductions were controversial. The British Mu-
seum’s Ethelwynn Trewavas, who saw her opportunity to
map Africa’s ichthyogeography slipping away, had complained
that people were moving tilapia around the continent “in a
slap-happy fashion” (Trewavas 1952). Much later, one-time
EAFRO director Peter Jackson lamented the introductions as
“woolly-headed” and “useless” (Jackson 2000). At the time,
however, the move was rationalized by EAFRO’s “seemingly
paradoxical conclusion that under tropical conditions the
more animals, particularly herbivorous animals, living in a
lake, the more animals that lake can support”(EAFRO 1953).
However, the introduction of a large predatory fish was
viewed with considerably more skepticism by fishery biolo-
gists. Because of the possibility that the Nile perch might
ruin Lake Victoria’s important tilapia fishery, Worthington
(1929) echoed Graham’s caution, urging that “the recom-
mendation made by Mr. Graham that no such project be put in
hand must be endorsed here [italics in original] until extensive
research has been carried out into the effects of the intro-
duction.” He later suggested an experimental introduction into
nearby Lake Nabugabo and concluded that “if the introduc-
tion is effected and a natural balance is struck between the Nile
Perch a nd the Lake Na bugabo fish es, the i ntroduction o f the
Nile Perch into Lake Victoria may be considered” (Wor-
The cautious stance of Graham and Worthington found
support in other quarters. Kenya fish warden Hugh Copley
(1940) wrote that
the question of a predatory fish in Lake Victoria is an inter-
territorial matter and any introduction should take place
only after a most exhaustive and searching investigation. It
has always been a worry to myself having [American]
Black Bass in Lake Naivasha, for it is always possible some
irresponsible person will take this fish and stock a dam
having an outflow (possibly during the season of heavy
rains) to some stream with an ultimate access to Lake Vic-
toria, and thereby introducing a predatory fish whether it
was advisable or not.
This memo captures the essence of the management
dilemma that took shape in the years following World War II.
First, the lake was shared by three territories,and different as-
pects of its administration fell to different organizations, all
of which were disjunct from fisheries research. Second, try-
ing to regulate the species composition of a lake the size of Vic-
toria in an era obsessed with bolstering production was a
monumental job.It implied both monitoring the numerous
rivers and swamps that abutted the lake and policing a 3500-
km shoreline to prevent any unilateral introductions.
Fisheries management in a developmental
The consecutive ravages of depression and war brought food
supply to the fore of the colonial mind. EAFRO, which owed
its existence to the beneficence of the High Commission and
the Colonial Office, was often pressed to aid in the under-
taking. In 1948, EAFRO director Robert Beauchamp received
an inquiry from the East African Industrial Research Board
in Nairobi about the prospects for an industry, based on the
lake, to “make fishmeal to supplement the animal protein ra-
tion which is deficient to the [tune] of some 1,000 tons per
annum” (EAIRB 1948). Beauchamp’s lukewarm response
prompted chastisement from an official at the Colonial De-
velopment Corporation in London, who urged that “if we keep
bashing at these problems, I think we will find some field for
commercial development!” (CDC 1949). In one extreme at-
tempt to boost production, London-based colonial fisheries
adviser C. F. Hickling (1953) recommended that the fishery
be totally deregulated: “It is possible to exterminate stocks of
game, hence the need for game sanctuaries; but it is in fact im-
possible to exterminate stocks of fish except in a few special
cases.... It would seem a wise principle to assume that a fish-
ery is in a sound condition, requiring no regulation, unless
the contrary can be proven.”
EAFRO’s reluctance to throw its weight behind such “prac-
tical” measures, and the tendency of its scientists to work on
problems that had no immediate economic application, was
almost its undoing. In 1954,Worthington received a letter from
the High Commission. “Sir,” it began,“I have the honour to
address you on the question whether or not there still exists
an economic need for fisheries research in the East African ter-
ritories” (EAHC 1954). Copley (1954), frustrated at the po-
litical naïveté of the EAFRO scientists, begged Worthington
to give him something with which he could justify further re-
search to his superiors:
Literally I stand between the Kenya Government with-
drawing its support from Jinja, and Jinja, if you
understand me. The Kenya Government would withdraw
their support tomorrow morning with the greatest of plea-
sure.... Tanganyika would do so the next day. What one is
fighting for is to get all these Governments to believe
that...a lot of the work has practical application NOW; if
we cannot, then good-bye to Jinja.
As far as the scientists were concerned, their various in-
vestigations needed no special justification. Administrators,
however, expected scientists in the colonies to be responsive
to political and economic imperatives. In one revealing
episode, Colonel S. P. Fearon of the High Commission dis-
patched a directive to EAFRO director Beauchamp:“You will
undertake a fishing survey of the deeper waters of the Lake,”
it instructed, and “you will exercise the strictest economy”
(Fearon 1955).This wording was so dictatorial that even the
Colonial Office blanched, but Fearon would not budge:
We ar e m e re l y t r y i n g t o l a y d o w n w ha t t h e Co u n c il e x p e ct s
Beauchamp to do, both for his benefit and the Council’s....
To d a y t h e s u c c e s s f u l s c i e n t i s t i s a m a n c o m m a n d i n g a
handsome salary with a host of lesser scientists beneath
him and a large, expensive and complicated organization
to manage.... The scientist of today, in fact, cannot expect
to have his cake and eat it. He must either accept the
restrictions which the expenditure of public money entails,
or he must be content to remain a scientist pure and sim-
ple. (Fearon 1955)
Thus, EAFRO scientists were not in a particularly strong
position to influence policy when the idea of introducing Nile
perch was revisited in the 1950s. Despite considerable effort,
the British had not been able to discover a commercial value
for the “trash” haplochromines. Graham (1929) had sug-
gested that they might be made into fertilizer; others posited
that their function was simply to die,thereby enhancing the
fertility of the lake (Greenwood 1966). Still others suggested
that they were vermin, in that some preyed on economically
valuable tilapia fry, and should therefore be exterminated
(Provincial Commissioner, Nyanza 1939).
The impetus for the revival of the Nile perch introduction
proposal was the Uganda Game and Fisheries Department
(UGFD), which brought together two men who advocated the
idea for different reasons. Bruce Kinloch, chief game warden
from 1950 to 1960, was a devoted big-game hunter and sport
fisherman, and he worked hard to expand the range of the
Nile perch, a “fine sporting and very edible fish” (UGFD
1951, Kinloch 1972). Kinloch’s chief fisheries officer Don
Rhodes believed, according to a contemporary, “that any-
thing whatsoever was justified if it could conceivably
advance the weal of the common man” (Jackson 2000).
Yet UGFD was hamstrung by “certain influential and
conservative-minded quarters” at EAFRO, which opposed
any Nile perch introductions (Kinloch 1972).
However, when the Owen Falls Dam was constructed in
1954, putatively sealing off Lake Victoria from the Nile, UGFD
came into sole regional jurisdiction over the upper Nile and
the attached Lake Kyoga. Within the year, UGFD officials
and local African fish guards had transferred a handful of Nile
perch from the base to the top of Murchison Falls (which
separates Lake Albert from the upper Nile). In 1955, UGFD
officer John Stoneman led a “proper” stocking expedition,
transferring 47 Nile perch from Butiaba on Lake Albert to the
Victoria Nile below the dam, and 100 more to Lake Kyoga at
Masindi Port (Kinloch 1972).
After these steps had already been taken, the debate over
whether to stock Lake Victoria grew louder, with the lines
drawn between EAFRO and UGFD. At a 1955 meeting, Kin-
loch requested consideration of the issue, arguing that al-
though the Nile perch would probably affect “various species
of fish which were of little or no commercial value,” it would
have minimal impact on tilapia (EAIFAC 1955). Opposition
from EAFRO hinged on the argument that the outcome of the
“exp eriment” w ith Nile perch i n Lake Kyog a sho uld be kn own
before an introduction into Lake Victoria could be considered.
Adopting a different tack, UGFD employees seized on a
paleontological study showing that a congener of the Nile
perch (Lates sp.) had occurred,and gone extinct, in the Lake
Victoria region during the Miocene (Greenwood 1951). Thus,
UGFD officials began calling for the reintroduction of the Nile
perch, while also alluding to “vague reports”that Nile perch
had already been seen in Lake Victoria near Port Bell (EAIFAC
1957). In face of stubborn resistance from EAFRO, UGFD of-
ficer Alec Anderson agreed to a hiatus on stocking operations
within Uganda,although he grumbled that he would “prefer
to see some such device as an electrical fence installed rather
than that there should be a complete prohibition on stock-
ing”(EAIFAC 1957).Anderson also engaged in a debate in the
East African Agricultural Journal with EAFRO scientist Geoffrey
Fryer. Fryer (1960) appealed to the “common-sense” princi-
ple of trophic inefficiency (Lindeman 1942) and argued that
to assume Nile perch would feed only on Haplochromis species
to the exclusion of tilapia was “wishful thinking.” Anderson
(1961) countered that Nile perch certainly would feed on “les
indesirables Haplochromis,”which “is [sic] generally regarded
as a [sic] ‘trash fish’ of very little value.”
EAFRO,perhaps recognizing that the Nile perch question
would not disappear, had belatedly begun to arrange for a
study of Nile perch biology, which they had long stated was
a prerequisite for considering the introduction. This work was
not begun until 1959 (EAFRO 1960),in part because of bud-
get constraints (themselves due to niggardly funding from the
High Commission, which had decided in 1958 to disband the
Lake Victoria Fisheries Service and distribute its duties to the
three territories). And almost before the work could get un-
der way, Nile perch began turning up in Lake Victoria. The
1960 EAFRO annual report stated that the need for the Nile
perch study had become all the more urgent,“since during the
year it became apparent that Nile perch had already gained
access to the lake by some means” (EAFRO 1960). In Octo-
ber of 1961, a Nile perch caught near Mwanza, Tanganyika,
was brought to fisheries officials there by an engineer who,hav-
ing worked for years on Lake Albert, was familiar with the fish
(Mwanza Fisheries Officer 1961).
These discoveries transformed the debate, and nobody
objected when Don Rhodes said in 1962 that “in view of
the evidence that Nile perch were already breeding in Lake
Victo ria and spreading rapidly, [I] would therefore like to stock
more fish immediately as these become available at Port Bell,
Kaazi, and Entebbe to satisfy the long-standing demands of
important sporting and commercial efforts in these areas”
(UFD 1962). Thereafter, the anthropogenic dispersal of Nile
perch did indeed spread rapidly (figure 1). Thirty-five were
introduced into Lake Victoria at Entebbe Harbor in May
1962; by November 1963,that total had reached 339. In 1963,
Nile perch were stocked “in the Kagera River, Lake Salisbury,
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784 BioScience • September 2005 / Vol. 55 No. 9
Lake Saka, Lake Nabugabo, Lake Kijanebalola, and various
dams” (UFD 1962/1963). Fishery officials in Kenya intro-
duced eight more Nile perch (from Lake Turkana) at Kisumu
It remains impossible to say with absolute certainty that
somebody within UGFD introduced Nile perch directly into
Lake Victoria before 1960. However, the available evidence
points strongly in that direction (although both Kinloch and
Rhodes denied having done so personally in interviews with
the author). Kinloch’s 1972 memoir and numerous official
documents from the time certainly evince a steadfast resolve
to spread Nile perch and a disdain for those who opposed the
idea, as does a report by American economist James A. Crutch-
field (1959), who worked closely with UGFD during his
tenure as a Fulbright fellow.
Most compelling, however, is the testimony of two
Africans who worked for UGFD in the 1950s. On 25
February 1978—shortly before the Nile perch boom—John
Ofulla Amaras published the following in a letter to the
East African Standard: “Please take note that Nile perch...were
stocked in Lake Victoria and Kioga [sic] from Lake Albert in
August, 1954. ..by mys elf assisted by fi sh scouts at that time
Augustino Kyomya, Benwa Magadu, Peter Karakaba and
others—under the directive of the then Senior Fisheries Of-
ficer, Mr. Alex [sic] M.Anderson.”
Figure 1. Map of the Lake Victoria region, showing the range expansion of the Nile perch in East Africa during the 1950s and
1960s. Dots show locations and years of deliberate introductions: (1) Murchison Falls; (2) Masindi Port; (3) the upper Nile
below the Owen Falls Dam; (4) Port Bell; (5) Entebbe Pier; (6) Lake Nabugabo; (7) Lake Kijanebalola; (8) the Kagera River;
(9) Lake Saka; (10) Lake Salisbury; (11) Kisumu. Arrows indicate entry of Nile perch into Lake Victoria; question marks indi-
cate uncertainty. The asterisk shows the point of origin of Nile perch introduced into the Ugandan waters of Lake Victoria, at
Butiaba on Lake Albert; the Nile perch introduced at Kisumu in 1963 came from Lake Turkana in northern Kenya (not
shown). The fish icon represents the point of furthest advance, near Mwanza, Tanganyika, by 1961.
Amaras, a Kenyan, was indeed a UGFD fisheries assistant
from 1954 to 1955 (UGFD 1955); in a 2003 interview with the
author,he claimed that multiple introductions of Nile perch
from Lake Albert had been made into Lake Victoria at Port
Bell and Entebbe Pier over several months in 1954 (these are
the same locations subsequently proposed by Don Rhodes in
1962). Peter Karakaba, named in Amaras’s letter, also stated
in a 2003 letter to the author that Nile perch had been in-
troduced directly into Lake Victoria, although he gave the date
as 1955. Former UGFD officer John Stoneman, in an inter-
view with the author, remembered Amaras’s having been in-
volved in the stocking of Lake Victoria, which would mean
that the introduction took place in either 1954 or 1955, as
Amaras was dismissed from UGFD in October 1955 (UGFD
It is unlikely that any existing evidence could conclusively
prove whether the initial introduction into Lake Victoria it-
self was intentional or accidental. UGFD officials have always
maintained that Nile perch must have entered the lake through
the turbines in the Owen Falls Dam when the dam was shut
down for cleaning, a claim that many scientists considered im-
plausible (Jackson 2000). In any case, it made little practical
difference whether the Nile perch was introduced directly into
the lake or into a river behind a penetrable dam.
Although a number of factors and individuals clearly con-
tributed to the Nile perch’s introduction, it is perhaps most
interesting historically to ask why EAFRO’s research biologists
failed in their attempts to prevent it.This is neither a criticism
nor an attempt to downplay the considerable importance of
EAFRO’s basic research during these years—much of it con-
ducted under difficult conditions. It is merely an attempt to
learn from history.
It is true that it would have been difficult for EAFRO to pre-
vent determined UGFD officials from transferring Nile perch
at least to the source of the Nile. However, it is possible that
if they had made a stronger attempt to push their agenda
through political channels from the beginning, the interter-
ritorial organizations of research and administration might
have been fused, as originally advocated by E. B. Worthing-
ton. Such an arrangement would have provided scientists
direct control over policy. Alternatively, EAFRO might have
been afforded a stronger intraterritorial role,such that mov-
ing Nile perch from Lake Albert to Lake Kyoga or the upper
Nile would at least have required EAFRO oversight.
A third possibility is that more funding would have been
forthcoming if EAFRO had more skillfully manipulated ad-
ministrative sentiment within the High Commission. As
early as Graham’s 1929 survey, EAFRO scientists had main-
tained that “extensive research” was required before Nile
perch introductions could be considered.Yet they were slow
to undertake such a study, and by the time they did, they found
it difficult to obtain funding from an administration convinced
that their work was too esoteric. It is tempting to speculate
what would have happened if, as Worthington suggested in
1932, an experimental introduction had been made into
Lake Nabugabo. What ultimately happened in Lake Nabugabo
was similar to what happened in Lake Victoria, with ap-
proximately 50 percent of indigenous fishes disappearing
from open waters (Chapman et al. 2003). This is hardly the
“natural balance” that Worthington (1932) was looking for.
However, it is not clear that even this would have pro-
vided EAFRO biologists with a compelling argument against
further introductions. Biologists such as the British Mu-
seum’s Ethelwynn Trewavas and Humphrey Greenwood val-
ued haplochromine cichlids as evolutionary curiosities, but
the argument that these cichlids had some intrinsic value was
never raised in fishery policy discussions.Instead, biologists
such as Fryer (1960) appealed principally to economics, ar-
guing that the Nile perch would devastate valuable established
fisheries. This turns out not to have been the case—indeed,
the Nile perch vastly increased the economic value of every
lake where it was introduced. To modern biologists, who
generally believe that biological diversity is a good in itself, the
term “trash fish” sounds odd, even offensive. But modern ecol-
ogy’s preoccupation with diversity and its benefits only really
began in the late 1950s (e.g., Hutchinson 1959). While EAFRO
biologists clearly believed that species were interesting things
to study, they would have found it hard to articulate policy
arguments based on the value of biodiversity. Simply, no
such “value” had yet been attributed to biodiversity.
Similarly, the study of biological invasions was in its
infancy in the 1950s (Elton 1958) and later drew heavily on
the observations that predator–prey, parasite–host, and
mutualist–mutualist relationships are coevolved (Ehrlich
and Raven 1964), and that invasive species can exploit or dis-
rupt those relationships.Whereas Fryer (1960) and others at
EAFRO clearly recognized that the introduction of a non-
indigenous apex predator could endanger fisheries, their
arguments could have been much stronger in,say,1970 than
they could possibly have been in the period 1954–1960.
It might be argued that no amount of cogent scientific rea-
soning would have made a difference—that government
agencies like UGFD tend to introduce nonindigenous species
regardless of scientific concerns, and that such introduc-
tions, once proposed, are so difficult to prevent as to be almost
inevitable. However, the history of the Nile perch in Lake
Victoria also offers an instructive example of applied sci-
ence being used to forestall such an introduction.In the late
1980s, it was proposed to introduce the Nile perch into still-
water bodies of tropical Queensland,Australia.After a detailed
study of the thermal tolerances of Nile perch, and careful
scrutiny of the consequences of the introductions in Lakes
Victoria and Kyoga, it was concluded that the introduction
“would be potentially disastrous for Australian aquatic fauna....
Consequently, the agency responsible for the evaluation
program has abandoned the concept of introducing the Nile
perch to Australia” (Barlow and Lisle 1987). The Nile perch
remains classified as a noxious species in Queensland.
It is also possible that the secretive introduction of a hand-
ful of fish would have been inadequate to establish the Nile
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786 BioScience • September 2005 / Vol. 55 No. 9
perch in Lake Victoria, and that the legally sanctioned mass
introductions after 1960 were crucial to its subsequent suc-
cess. A growing literature suggests that multiple introductions
can increase the genetic diversity of invading populations and
lessen the probability of stochastic extinction (Kolbe et al.
Incipient conflicts between biodiversity and economic or
infrastructural development persist today in various mani-
festations: new roads, new dams,new species introductions.
Thus, ecologists and evolutionary biologists might profitably
take several lessons from this story. The first is that there is an
important role for scientists who are willing to grapple with
policy,and with politics. While science itself should obviously
be apolitical, the systems that scientists study (and the eco-
nomic, legal, and social matrix in which they must operate)
are politically contested arenas. Thus,scientists who desire the
persistence of the systems they study (and the unfettered
ability to study them) are justified in being advocates in
matters on which their science can be brought to bear.
Ta k i ng t h i s r e a s o ni n g o n e s t e p f u r t h e r, i t i s n o t u n r e a s on a b l e
for scientists to consider how they might position them-
selves to exert political influence if and when it becomes
By the same token, this story highlights the importance of
both applied and basic research: a thorough and persuasive
argument against the introduction of the Nile perch would
have required both empirical data on the probable effects of
the introduction and a cogent theoretical framework to
express generally why the introduction of nonindigenous
species can be ecologically disastrous.
I am deeply indebted to those who discussed these events with
me: John Amaras, Peter Karakaba,Bruce Kinloch,Rosemary
Lowe-McConnell,Don Rhodes, John Stoneman, and Robin
We l co m m e . Jo h n Ba l i r w a a n d t h e st a f f s o f R h od e s Ho u s e L i -
brary, the Public Record Office, and the Kenya National
Archives kindly helped me locate archival material. Financial
support was provided by the Thouron family and by St.
John’s College, Oxford. Finally, I am grateful to Dave Ander-
son, William Beinart, Kai Chan, Paul Ehrlich, John Fay, and
Jessica Shors for advice and help with the manuscript.
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