TED Case Studies

Nile Perch, Trade and Environment

Go to TED Super Page

     CASE NUMBER:   206


     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 


    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 


    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 


    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









    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 


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 


    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,


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


    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, 


    2Interview with Les Kaufman, Head of Edgerton Research 

Laboratory of the New England Aquarium, Boston, 1 March 


    3Reynolds, J. Eric, "Socio-economic effects of the

evolution of Nile perch fisheries in Lake Victoria: a

review," (Rome, 1988, FAO).

    4"People, Fisheries..."


    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 


    8"People, Fisheries..."

Go to TED Super Page