TED Case Studies
Nile Perch, Trade and Environment
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Nile Perch, Trade and Environment
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CASE NUMBER: 206
CASE MNEMONIC: PERCH
CASE NAME: Nile Perch, Trade and Environment
A. Identification
1. The Issue
In forty years or less, virtually all of the natural,
biological "wealth" unique to Lake Victoria has been
destroyed. At one time the lake contained over 400
endemic species of haplochromines whose extraordinary
diversity and speed of evolution were inspiring to
scientists concerned with "the forces that create and
maintain the richness of life everywhere."1 Today, a mere
handful of species exists, threatened on one hand by a
fearsome enemy - the Nile perch (Lates niloticus) - and on
the other by the lake's changing conditions.
2. The Description
Due to the presence of the Nile perch, the natural
balance of the Lake Victoria ecosystem has been disrupted.
The food chain is being altered and in some cases, broken,
by the indiscriminate eating habits of the Nile perch.
The subsequent decrease in the number of algae-eating fish
allows the algae to grow at an alarming rate, theregby
"choking" the lake. The increasing amounts of algae, in
turn, increase the amount of detritis (dead plant
material) that falls to the deeper portions of the lake
before decomposing. As a byproduct of this decompostion,
the oxygen levels in the deeper layers of water are being
depleted. Without oxygen, any aerobic life (such as fish)
cannot exist in the deeper portions of the lake, forcing
all life to exist within a narrow range of depth. In this
way, the Nile perch has degraded the diverse and thriving
ecosystem that was once Lake Victoria.
The abundance of aquatic life are not the only
dependents of Lake Victoria. More than thirty million
people in Kenya, Uganda, and Tanzania rely on the lake for
its natural resources. The fishing industry, in
particular, is suffering. With traditional food sources
all but extinct, and nets continuously damaged from the
sheer force of the Nile perch, local fisheries have had to
abandon their work. The costs of scarce wood that is
burned to dry the Nile perch and of large processing
plants that are built to prepare the fish for market
preclude many fisheries from entering the Nile perch
market. Only fisheries with large financial resources
have been able to switch to catching the Nile perch.
Given time, however, the supply of Nile perch will
diminish as its food supply dwindles, making these
fisheries unsustainable.
The following is the story of Lake Victoria and the
results of an historic meeting in which scientists,
resource managers, and policy makers came together to
create an agenda to rehabilitate it.
Lake Victoria's ecology and natural resource base has
been dramatically altered through the introduction of the
Nile perch (Lates niloticus). In the 1950s, a proposal to
increase fish catches in the lake by introducing the Nile
perch was adamantly opposed by scientists who feared that
the lack of a natural predator for the fish would result
in the imminent destruction of the lake's bountiful
ecosystem. Despite the controversy, a colonial fisheries
officer was ordered to clandestinely put the Nile perch
into the portion of the lake that is in Uganda.2
Thereafter it was introduced intentionally in both 1962
and 1963. By 1964 the Nile perch was recorded in
Tanzania, by 1970 it was well established in Kenya, and by
the early 1980s it was abundant throughout Uganda,
Tanzania, and Kenya, the three countries surrounding Lake
Victoria.
Having no natural predators in the lake and a plethora
of food, the Nile perch flourished, often reaching up to
250 kgs., forcing it to eat constantly to sustain itself.
Such eating habits are no longer sustainable. The Nile
perch has caused mass extinctions among haplochromine
populations. With little available food sources
remaining, the Nile perch has taken to cannabalism with
the larger fish feasting on the smaller ones.
Hundreds of endemic species that evolved under the
special conditions offered by the protection of Lake
Victoria have been lost due to extinction, and several
more are still threatened. Their loss is devastating for
Lake Victoria; the fields of ecology, genetics, and
evolutionary biology; and more evidently, for the local
fisheries.
Local fisheries once depended on catching the
tilapias, catfishes, carps, and lungfishes that comprise
the local diet. Today, the compositions and yields of
such fish catches are virtually negligible. Extensive
fish kills, Nile perch, loss of habitat, and overfishing
have caused many fisheries to collapse and many protein
sources to be unavailable at the market for local
consumption.
Few fisheries have been able to make the switch to
catching the Nile perch which requires a significant
amount of capital resources. Unlike traditional fish
catches, the Nile perch must be dried over a fire; relying
on large amounts of scarce wood for fuel has led to an
increasing rate of deforestation. After drying, the fish
is either transported to the local markets or prepared for
export. Selling Nile perch at the local markets is not
the most profitable option for the fisheries. One
explanation is that its unpopularity has kept it from
being fully integrated into the local diet. A second
explanation is that there are few fisheries with the
technology, capital, and infrastructure to move the fish
further than local markets, let alone export them, so
local market prices are kept relatively low by the surplus
of supply over demand.
A small number of processing plants have been
established to filet, freeze, and prepare the Nile perch
for export to Europe and Israel where it will receive a
higher market value. In Kenya, Israelis were snuck in to
assist with the building of processing plants. 54.9% of
their export volume went to Israel and 22.8% to Spain in
1987.3 General lack of control over the processors and
exporters is resulting in the heavy exploitation of the
Nile perch without any concern to the sustainability of
the fisheries.
An important off-shoot of this problem is that the
socio-economic characteristics of the fisheries
populations are changing as the inequalities of economic
opportunities increases, creating a widening gap between
those with access to capital resources and those without.
Researchers, conservationists, and policy makers met
in Jinja, Uganda in 1992 to discuss options to
rehabilitate Lake Victoria. Several groups were convened
to prioritize research needs and develop recommendations.
The following is a comprehensive list of issues the groups
concerned themselves with during this period:
a. riparian wetland ecotones
b. fish biology, management, and conservation
c. fisheries management
d. biodiversity and conservation
e. socioeconomics
f. fishery policy, management, and socio-economics
g. commodity systems and the dynamics of capital
h. fisheries management and extension
i. immobility and persons at risk
j. nutrition and fisheries
k. fisheries regulation and development
l. limnology and environment
At the conclusion of the meeting a long and detailed
list of resolutions was compiled. Resolutions important
to this case include:
a. captive propagation of native species of food fish;
b. restoration and rehabilitation of indigenous stocks;
c. overfishing of Nile perch in specified areas; and
d. expansion of aquaculture to help meet basic needs.
More importantly, the decision was made to combine
research, disseminate information, enforce regulations,
and coordinate fisheries development and management among
the three riparian states.
3. Related cases
BALLAST Case
TILAPIA Case
WALLEYE Case
SALMON Case
SALMON2 Case
MUSSEL Case
APPLE Case
FLORIDA Case
Lake Victoria's battle with the Nile Perch has its
parallels in the struggles of Lake Erie with Zebra Mussles
and Lake Malawi with Talapia. In each case, the foreign
species has been introduced into the lake and its
prosperity has adversely affected the natural balance of
its host. Consequently, it has also disrupted the fishing
industries and impacted the fishing community both
economically and socially.
Key words:
1) Lake Victoria
2) Nile perch
3) Biodiversity
4. Draft Author: Ellen Grosman
5. Discourse and stage: DISagreement and Allege
6. Forum and scope: KENYA and REGION
It is a domestic problem that naturally encompasses
three countries. Scientists from all over the world,
rather than legislative bodies, have been the key actors
in researching, designing, and implementing conservation
plans and strategies. They are involved at the request of
the Fisheries Research Institutes of the riparian states
of the Lake Victoria Basin.
A Lake Victoria Fisheries Commission has been
established to implement and sustain management and
research.
7. Decision breadth
More than seventy scientists, conservationists, and
ministers of fisheries attended the 1992 conference in
Jinja, Uganda to develop a research agenda to face the
challenges of Lake Victoria's ecosystem.
8. Legal standing
The culmination of research and workshops is an action plan
for management and conservation of Lake Victoria.
9. Geography
a. Geographic domain: Africa (the Nile)
b. Geographic site: East Africa (EAFR)
c. Geographic impact: Kenya
10. Sub-national factors: no
11. Habitat: TROPical
12. Type of measure: Regulatory Standard [REGSTD]
13. Impact: INDirect
14. Resource impact
a: Directly related: yes FISH
b: Indirectly related: no
caught in the nets)
c: Not related: no
d: Related to process: yes DEFORestation
15. Product type: Fish
Fish is sold fresh and as frozen filets.
16. Industry output:
The total value of the Nile Perch is nearly three
hundred million US dollars per year.4
Nile perch value Total industry value
Kenya 114648 (KSHS '000) 237333 (KSHS '000)
Tanz. 114525 (TSHS '000) 263838 (TSHS '000)
Uganda n/a n/a 5
In both Kenya and Tanzania the Nile perch constituted
about one-half of the total industry value in 1986.
At April 1993 exchange rates of approximately 66 KSHS per
dollar and 500 TSHS per dollar this converts to:
Nile perch value Total industry value
Kenya USD 1,737,090 USD 3,595,954
Tanz. USD 229,050 USD 527,676
Uganda n/a n/a
It is impossible to quantify how the amount of people
employed in the fisheries has been affected by the Nile
Perch. Statistical information from the respective
countries, if it exists, is inaccurate, outdated, and does
not account for the informal sector. The Information
Counselors at the Kenyan and Ugandan Embassies hesitantly
offered rough estimates, whereas at the Tanzanian Embassy
no guesses were hazarded.
Kenya: Fisheries employment around Lake Victoria was said
to be 3,000 in the formal sector and 20,000-30,000 in the
formal and informal, collectively.6
Uganda: In the entire country, the fisheries are said to
employ 5,000 formally and 20,000-40,000 collectively, in
the formal and informal sectors.7
17. Impact: High
18. Industry sector: FOOD
19. Exporters and Importers: Kenya and Israel
20. Environmental problem types: SPLS (species loss-sea)
21. Name and number of species: hundreds are involved
It is estimated that before the introduction of the
Nile perch there existed approximately 400 haplochromine
cichlid species and 40 non-cichlid species, many of which
were endemic. Today, no one knows just how many have
survived. "Haplochromines have nearly vanished, with at
least half the fauna feared extinct. Table fishes
[tilapias, catfishes, carps, lungfish] have declined
sharply, with the most important among them, the ngege
(Oreochromis esculentus), extinct but for a few scattered
populations in time lake basin ponds and reservoirs. Even
catches of the introduced Nile perch, now the mainstay of
the fishery, have shown signs of falling off."8
22. Resource impact: HIGH
Lake Victoria is running through its life-cycle at a
rate approximately four times greater than what should be
its natural rate. The Nile perch are devouring all but a
few species of fish, including its own. With no small
fish to feed on algae, its growth is "choking" the top of
the lake and its decay is depleting the lower levels of
oxygen.
Due to the relative economic immobility of persons in
the fishery, low returns to catches does not prevent
exploitation. Rather, it is likely that without
alternatives, they will fish to commercial extinction. In
Kenya, where even the littlest minnows have been
overfished, people are forced to turn to shrimp for
purposes of economics and nutrition.
The export of Nile perch has driven its cost well
beyond the means of locals. Combined with limited numbers
of fish in the local markets, locals are deprived of an
important source of protein.
23. Urgency of problem: LOW
24. Substitutes: CONS
25. Culture: yes
26. Human rights: no
27. Trans-border issue: yes
28. Relevant literature
Baskin, Yvonne. "Africa's troubled waters: fish
introductions and a changing physical profile muddy
Lake Victoria's future." BioScience. v.42,
pp.476-81.
Chamberlain, Joan. "Oxygen loss threatens Lake Victoria."
New Scientist. v.135, p.8.
Kaufman, Les. "Catastrophic Change in Species-Rich
Freshwater Ecosystems: The lessons of Lake Victoria."
BioScience. 4.42, pp.846-58.
------------. personal communication. 1 March 1994.
"Nile perch eats all and sundry in its new home." New
Scientist. v.109, p.24.
Okie, Susan. "The race to save a dying lake." The
Washington Post, July 7, 1992, A:1:1.
Payne, Ian. "A lake perched on piscine peril." New
Scientist. v.115, pp.50-54.
"People, Fisheries, Biodiversity, and the Future of Lake
Victoria." Proceedings of the Lake Victoria Ecosystem
Workshop held in Jinja, Uganda, Aug. 17-21, 1992.
Boston: Edgerton Research Laboratory of the New
England Aquarium, 1993.
Reynolds, J. Eric. "Socio-economic effects of the
evolution of Nile perch fisheries in Lake Victoria: a
review." Rome, 1988. FAO
ENDNOTES
1"People, Fisheries, Biodiversity, and the Future of
Lake Victoria." Proceedings of the Lake Victoria Ecosystem
Workshop held in Jinja, Uganda, Aug. 17-21, 1992. (Boston:
Edgerton Research Laboratory of the New England Aquarium,
1993).
2Interview with Les Kaufman, Head of Edgerton Research
Laboratory of the New England Aquarium, Boston, 1 March
1994.
3Reynolds, J. Eric, "Socio-economic effects of the
evolution of Nile perch fisheries in Lake Victoria: a
review," (Rome, 1988, FAO).
4"People, Fisheries..."
5Reynolds.
6Interview with William Meda, Information Counselor of
Kenyan Embassy in Washington DC, 13 April 1991.
7Interview with Nimisha Madazani, Information
Counselor of Ugandan Embassy in Washington DC, 13 April
1991.
8"People, Fisheries..."
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