The rise and fall of the Nile princess

In recent decades - after reaching a peak due to the population of Lake Victoria with the predatory fish that was not there before, the fishing productivity in Lake Victoria is decreasing due to overfishing and mortality due to water pollution. The fish population, which for about 70 years constituted the bulk of the fishing harvest and the bulk of the income for those living around the lake, is dwindling and the fishermen around Lake Victoria are suffering

In the square of one of the largest cities in Tanzania (Mwanza) Mwanza, which lies on the shore of Lake Victoria, stands a large statue, not of a national hero or a European explorer, but of a fish.

There is a good reason for the fish statue, since the most important source of livelihood for the city's residents is the fisherman, and in the last seventy years the fisherman of the Nile princess, the fish that caused the development of enterprises and industries around the lake in Uganda, Kenya and Tanzania, since the Nile princess is a large fish, and in order to preserve it, it is necessary to smoke, when The fuel for smoking was provided by forests cut down around the lake. Slaughterhouses and cold stores were established to prepare the fish for export. These projects attracted millions of people to the area around the lake so that in the 30s and 200,000s around XNUMX million people settled around the lake. During these years, XNUMX tons were fished in the lake every year (more than in the big lakes in the USA and Canada), and the boom in fishing turned one of the poorest areas in East Africa into a developing area and the princess was given the title "the savior fish".

So far a positive picture emerges, But what brought me to approach the subject is knowledge Due to the dwindling of the fishery to the extent that causes many of the residents around the lake to return to conditions of extreme poverty, many leave the lake and migrate to the big cities in the hope of finding a livelihood (migration to the cities is a global phenomenon).

The Nile princess fish inhabited lakes in Africa but until about seventy years ago it was not in Lake Victoria, there were many different species of fish in the lake and most of the catch was of small fish that were used for local consumption and in order to market them in the urban markets they dried/preserved them in the sun, (a form of processing that is not suitable for the Nile princess the giant).

The Nile princess is a predator and as such since entering the lake it destroyed a significant part of the original fish population, now that the princess population is dwindling there are no fish of other species to fill the gap and the human population around the lake is suffering.

Anyone who has visited East Africa knows that the most common fish in markets and restaurants is what we know as the Nile princess, ( Lates niloticus ), a predatory fish from the Dekraim series that is common in freshwater bodies in Africa. In the XNUMXs, despite the opposition of scientists, Lake Victoria was populated by the Nile princess fish, intentionally or by accident, the princess fish invaded the lake, preyed on the original fish populations and became the main fish that lived and was caught in the lake.

In recent decades, fishing productivity in Lake Victoria has been decreasing due to overfishing and mortality due to water pollution. The fish population, which for about 70 years constituted the bulk of the fishing harvest and the bulk of the income for those living around the lake, is dwindling and the fishermen around Lake Victoria are suffering.

The Israeli connection

In the past I mentioned the involvement of a good Israeli who "helped" the fishermen who live around Lake Victoria, I put the "help" in quotation marks because of the doubt whether his actions actually helped. The same Israeli sat by the lake on the Kenyan side and engaged in raising Nile princess fish in the ponds during the period when Uganda and Kenya were under the British mandate (the 50s), the attitude and understanding of the environment was limited and so was the understanding that the Nile princess is a foreign fish to Lake Victoria.

 There are different opinions about the process of the princess inhabiting the lake. There are stories about fish being washed away from one of the breeding ponds, but (according to a conversation with the Israeli's son) the stocking was probably intentional and was done with the support of the British Mandate government which foresaw the possibilities of exporting the fish to countries outside of Africa, such as Europe and the Middle East. Intentionally or accidentally, the result was almost immediate - the new invader preyed on the local fish species and its population grew.

The local fishermen who were used to treating small fish by drying them needed to learn how to treat the princess that reaches much larger dimensions, treatment by smoking that caused deforestation, or accommodation in cold stores whose construction and destruction cause environmental pollution, meaning that handling the invasive fish caused serious environmental damage.

So what did we have:

Inhabiting a huge lake with a predatory fish that behaved like a typical invader and preyed on the local fish population, deforestation around the lake to provide wood for smoking the fish, development of slaughtering and storage projects that attracted thousands of workers, pollution of the lake water by the industries associated with fishing, pollution that gave a death blow to the remaining population The original fish, overfishing that led to the depletion of the princess population. If in the past the average weight of a fish was about 50 kg, then today the average weight has dropped to 10 kg.

Following the decrease in the fish harvest, factories and related industries were closed, - and as a result, many of the approximately 30 million people who lived around the lake experience poverty and migrate to the cities in search of a livelihood.

Thus, with a positive economic intention but with a lack of consideration for environmental data, the British and Israeli mandate officials "helped" an offensive and harmful invasive species to pollute one of the largest lakes in the world.

More of the topic in Hayadan:

• The earliest evidence of aquaculture 3,500 years ago - in the eastern Mediterranean
• The Great Invasion
• Invasive / alien species
• Operation of the "Renaissance" dam in Ethiopia has begun despite protests from Egypt and Sudan
• A special project for the knowledge site: mapping the world's water problems