Fishing on Lake Victoria – History, Economic Impact and More
Table of Contents
History of Fishing on Lake Victoria
Between 1927-1928 Michael Graham carried out the first-ever coordinated fisheries survey of Lake Victoria. In His survey, two species were considered as endangered tilapia species, namely Victoria tilapia (O. variabilis) and the ‘Ngege’ or Singida tilapia (Oreochromis esculentus]. There are other relevant monitored species such as the Marbled lungfish (Protopterus aethiopicus), African Sharptooth catfish (Clarias gariepinus), Elephant-snout fish (Mormyrus kannume), Ripon barbel (Labeobarbus altianalis), Ripon barbel (Labeobarbus altianalis), and Semutundu (Bagrus docmak).
Haplochromis guiarti and Haplochromis cinereus have been suggested to be the most common species in the Lake. In his former report that was carried out through a survey, Graham communicated that “The Satu Tilapia esculenta or ngege” is the more significant food source found in the Lake, be it for the native consumption or the non-native’s consumption. With its size and quality of flesh, it stands above all other fish in the lake, for it is easy to trade and acquire because it travels in great numbers more than most other fishes around, like the Bagrus sp and semutundu (Luganda].
Graham added that the approval of the European flex gillnet of five-inch mesh had beyond reasonable doubt reduced the number of ngege in the Kavirondo Gulf, Smith’s Sound, the northern shore of the Lake, and the Sesse Islands areas convenient to market locations. By the dawn of 1954, the Lake’s victorious environment was characterized by an enormous variety of fish. It was home to over 500 species of fish, 90% of which were Cichlids, a bloodline of the haplochromines. It has been said over the last 15,000 years in Lake Victoria, Cichlids have evolved, and their extraordinary ability to rapidly adapt to extreme and diverse environments has made them unique. And this gave them the nickname “evolutionary plasticity” and made them the most successful species in the Lake.
Approximately 80% of the Lake’s fish biomass came from haplochromine species, an abundance that led Graham to believe the species would support a trawler fishery of about 200 boats. This affirms the idea that Lake Victoria was the most diverse fish environment on planet earth. The Cichlids of Lake Victoria managed to exploit virtually every food source available, including plants, animals, and loose materials. Haplochromine families are relatively bony and small and were never favored during fishing. The population living beside the Lake instead tends to favor the Lake’s two easily accessible species of Tilapia (O. variabilis and Oreochromis esculentus). Hence by the late 1940s, the British authorities were contemplating the overall ecological efficiency of the Lake, and some suggested that a predator needed to be inserted into the Lake to turn the haplochromine fish stock into something more economically viable. The predator in mind was the Nile perch (Lates niloticus). All those in favor of introducing a predator into the Lake argued as follows,
Firstly, prove from other African lakes points to the fact that the Nile perch could do exceptionally well commercially. If introduced into the Lake, it would undoubtedly feed on the haplochromines, thus improving the fishery’s overall value. Additionally, anglers may turn their attention to catching it by introducing such a fish, thereby alleviating some of the pressure on the tilapia stock. It was argued that since the Nile perch can weigh up to 200 kilograms (440 lb), anglers will be encouraged to use larger meshes to cash it. Furthermore, according to reports, Perch prefers offshore areas, which will relieve pressure on the inshore tilapia fishery.
Secondly, in the lakes where the Nile perch was indigenous, it coexisted with tilapia species, posing no threat to Lake Victoria’s commercially important tilapia stock.
Thirdly because of its potential size, the Perch made for an excellent sport fish, which might attract sport fishers and tourists to the lake area.
Finally, archaeological evidence near Lake Victoria suggests that an ancestor of the Nile perch may have been indigenous to lake Karunga, lake Victoria’s Miocene predecessor. Hence the argument was made that if the Perch had once been a native of the Lake, there was no reason why it couldn’t be one again.
The arguments against the Nile Perch were as follows:
Due to their nutritional needs, predators can never be as abundant as non-predators. In another light, the amount of fish that a Nile Perch must consume to produce a kilogram of the flesh is far more significant than the amount of greenery a tilapia must consume to do the same. Nile Perch is an inefficient species from an ecological standpoint. As aforementioned, because tropical waters are rich in nutrients (mainly detritus), their fertility is determined by the rate they are brought back into solution. However, the Nile Perch does not consume these loose fragments, so there is no reason to believe that its introduction would significantly impact the Lake’s overall ecological efficiency. An herbivore or a detritivore should be inserted if any fish needs to be introduced.
Also, to assume that the Nile perch would only consume haplochromines is wishful thinking.
Finally, Tropical ecosystems are complex, so it is impossible to predict what might occur with the introduction of the Nile perch.
While the argument for and against proceeded, it was unanimously agreed that tilapia stocks needed bolstering mainly due to increasing fishing on Lake Victoria created pressure on aboriginal species, associated with the expansion of the sales for fresh fish in the 1940s. The introductions of Tilapia started at the beginning of the 1950s with Oreochromis leucostictus from Entebbe, then by Tilapia zillii (Winam Gulf, 1953), T. rendalli (Winam Gulf 1953/54), O. niloticus (Kagera River 1954), and O. mossambicus (Entebbe 1961/62) followed. Because Tilapia feeds on loose materials and plants, their introductions were regarded as less harmful to the entire life of the sea than the introduction of a species that feeds on other species.
Despite the argument over the introduction of the Nile Perch in the early 1960s, it appears that it was already inadvertently introduced from Uganda in 1954. After discovering it in the Lake, other official introductions were made in 1962 and 1963.
During the 1950s and 1960s, introduced tilapia species failed to establish themselves in the Lake. However, the Uhuru Rains flooding in the early 1960s caused the lake level to rise considerably, flooding large areas of the shoreline and providing new breeding grounds for fledgling tilapia stocks, enabling them to compete with indigenous species. Of the six exquisite species introduced, two O. zillii and Oreochromis niloticus, by the early 1980s, these two were believed to have established themselves so as to be the main two Tilapia catches in the Lake. Of the indigenous species, O. esculentus was eradicated from the Lake due to competition with the newly introduced tilapias, while O. variabilis populations significantly declined.
The Nile Perch is a solid predator. When a checked specimen stored at the Kisumu Museum in Kenya weighed 184 kg (406 lb) confirms its enormous nature. The Populations of the fish affirmed themselves in a right-handed motion around the Lake, starting in Uganda, later by Kenya, and ending up in Tanzania. The amount of Nile Perch fishing on Lake Victoria was initially relatively small but rapidly increased in the 1980s, marking the ‘Nile Perch boom’ beginning. “At first glance, it appears the lake has become a fish farm that can only be described in gargantuan terms since Lates [Nile perch] made its debut.”
The Nile perch introduction had a deciding effect on haplochromine stocks that it favored as its primary kill; their abundance and diversity were affected. Approximately 40% of the haplochromine species are known to have been driven to extinction after Nile Perch was introduced, causing the fish biomass in the Lake to decline from 80% to less than 1%. According to researchers, this may be the most significant extinction event among vertebrates in the 20th century and has been referred to as the “most dramatic example of extinction that humans have caused within an ecosystem.”
After being Freed from their evolutionary hunters, the populations of the small native silver cyprinid [Rastrineobola argentea (mukene in Ganda Omena in Luo, and dagaa in Swahili) Thrived, growing into enormous shoals. In the same vein, pied kingfisher (Ceryle rudis) inhabitants that had previously been feeding on haplochromines expanded considerably due to the new feeding ground. Other similar and positive impacts have been witnessed throughout the entire ecosystem. Based on its evolutionary plasticity, haplochromines should have no problem adapting rapidly to the new environmental conditions caused by the Nile Perch explosion and unique richness in minerals and organic needs. This evidence was found from the Lake. One haplochromine, H. (Yssichromis) pyrrhocephalus, a species from the floating Organism in the Lake, was almost pushed to extinction by the Nile Perch. These species have recovered alongside increased fishing on Lake Victoria together with the exploitation of the Nile Perch, at that time (the 1990s) when water clarity and dissolved CO2 levels had declined due to the enrichment of the lakes with minerals and nutrients. Over a period of 20 years, H. pyrrhocephalus responded to heightened oxygen deficiency by increasing its gill surface area by about 64%; Head length, eye length, and head volume saw a decrease in size; meanwhile, cheek depth increased. The former surface structural changes may have happened to accommodate this increase in gill size. Other surface structural changes suggest adaptations relating to the presence of more significant and more challenging prey types.
Towards the end of the 1940s, fish stocks were under immense pressure. The fish market grew with the availability of railways to quickly transport fish to the coast and other settlements. Also, improved boats involved with fishing on Lake Victoria and nets were made available. The British authorities decided to remedy the situation by introducing exotic species, like Nile Perch and Tilapia. 5 significant impacts resulted from these introductions. The first of them was the emergence of the Nile Perch. After taking some time to establish itself, the fish began showing up in catch statistics only in the mid-1970s. Nile Perch “boom” became familiar in the 1980s as a result of the species explosion. The height of the peak of the catches increased from 335m in 1975 to about 380 776m by 1990
The second impact was the Nile perch’s destruction of the haplochromine species flock, its primary food source, and the complete crash of the species.
The third impact is in connection to Lake’s small endemic silver cyprinid, the dagaa. Its Monopoly (with haplochromine species) as food sources allowed it to thrive. It was not the primary target of the Nile Perch, and catches rose exponentially from 13,000 mt in 1975 to a legendary record of 567,268 mt in 2006.
The fourth primary impact of the introductions saw the firm establishment of the Nile tilapia (Oreochromis niloticus) in the fishery world. Tilapia catches from the Lake increased from about 13,000 mt in 1975 to a whopping 105,000 mt in 2000. It can be concluded that these introductions save the fishery world from collapsing. Finally, with such productivity and increased change, so too the entire production system and health of the Lake.
Finally, before the arrival of the colonial administration, the fishery was controlled by fishermen Soley, although specific fishing methods were reserved for women who owned their labor and their fishing equipment. Playing its role in the near-collapse of the fishery in the 1940s and 1950s was the re-adjustment of the fishery into fleets drawing on paid labor and more improved equipment. The Nile perch ‘boom’ was to help facilitate and massively expand this process. The emergence on the European market for high-quality white fish meat coincided with the development of industrial Fish processing facilities along lake Victoria’s shores in Entebbe, Mwanza, Kisumu, Musoma, and Jinja. In addition to the European Union [EU], Nile Perch is exported to the United States, Australia, and the Middle East, which brings in large sums of foreign exchange for the states along the coast.
In Uganda, the Nile Perch export earnings are second only to coffee in rankings. In 2006, the total net value of Nile perch exports was estimated to be US$250 million. The primary market for the Perch remains the European Union, which makes the industry to be subjected to all EU laws, health and safety inspectors. Due to inadequate hygiene and cholera outbreaks, the EU has sometimes closed its export doors to other states. Two Americans founded victory farms in 2015. They are now becoming the fastest-growing fish farm in sub-Saharan Africa.
The value of fishing on Lake Victoria has increased exponentially due to the high demand for Nile Perch. Not only that, but labor has also witnessed an increase with an approximated 12,041 Boats on the Lake in 1983. And by two decades later , There were 51,702 boats and 153,066 fishermen. The business of fishing on Lake Victoria has also employed multitudes of fish transporters, factory employees, and fish processors. In response to the fishing crew’s needs, boomtowns have developed along the Lakeshore. These towns resemble shantytowns with little in the way of service. In the 2014 frame survey, only 20% of 1433 landing sites provided communal restrooms, only 4% provided electricity, and only 6% were equipped with portable water. From Darwin’s Nightmare Documentary of 2004, you can find the impact of Perch fishing on the local economy.
The Nile Perch fishing on Lake Victoria has been a controversial topic with the conservationist seeking to preserve the unique nature and ecology of the Lake. In contrast, others recognize the importance of the economy and poverty alleviation that Nile Perch fishery would provide. Empirical evidence of the 1990 survey shows that most riparian states suffer from malnutrition due to the export of their prominent source of protein, which is fish. Thus, commercialization and export of the dagaa and Nile Perch undermine the survival of households, with an estimated 40.2% of children being prevented from thriving due to lack of protein. However, this is lower compared to the inland communities. At the fish landing sites, 5.7% of mothers were diagnosed to be chronically malnourished.
The three countries shearing boundaries with Lake Victoria [Kenya, Tanzania, and Uganda] have agreed in principal terms to the idea of taxing the Nile Perch exports, earnings to be applied to various projects that will benefit the local communities and sustain the fishery. However, this tax hasn’t been put into effect, enforcement of environmental and fisheries laws are generally weak, and the Nile perch fishery remains in totality a mining operation thus far.
For more articles related to lakes in Tanzania and their inhabitants click here!