Water Hyacinth Series [Part 2]

Lake Victoria

May is such a fantastic time to visit Kisumu. At the tail end of The Long Rains, the fleeting nimbus cast a long enough shadow to cool what is normally a hot and humid atmosphere. This is the kind of weather that tempts a traveller to go out and explore the city. But most people don't come here for the city; they come for its heart, Nam Lolwe.  

Nam Lolwe is a Dholuo name for an iconic body of water. It roughly translates to ‘lake that stretches as far out as the eye can see,’ an apt description for what is the largest lake in Africa – and the second largest in the world by surface area – Lake Victoria. 

An Economic Hub

Lake Victoria straddles three countries; Kenya, Uganda, and Tanzania. Here, it sits at the centre of a trilateral maritime trade network that generates around $6 billion worth of trade each year, far below its stated potential of $60B/year. 

But its greatest dependents by far are those with livelihoods tied directly to the lake. Millions of people, from fishermen to fish farmers, fishmongers, boat makers, tour guides, hoteliers, and researchers derive their bounty from these waters. 

The lake is, after all, the largest freshwater fishery in Africa. Between 800k and 1M tonnes of fish are caught in nets every year. Ashore, these are worth around $600 million, and they generate a further $250 million via exports to other regions.

All these stats show just how valuable an economic resource L. Victoria is. Unfortunately, this resource is under constant threat from one of the biggest ecological disasters of modern times; water hyacinth. 

The Unwanted Lilly 

Water hyacinth isn't actually a lily. True lilies take root in the soil beneath the water, with circular floating pads and flowers that sit slightly above the water. Hyacinth, on the other hand, is a free floating plant with roots that dangle in the water and flowers extending well above the surface. 

Thinking it an exotic lily, however, Belgian colonists in Rwanda and Burundi imported the plant as an ornamental for their garden ponds. By the 70s, the highly invasive plant had multiplied and floated its way into rivers and waterways in the local area. L. Victoria’s fate was sealed once the plant reached R.Kagera. 

This river empties its waters into the lake. So by the 80s, clusters of water hyacinth could be found around the its mouth. And with all the nutrients to feed on and no natural predators to feed on, it wasn't long before L.Victoria had a full blown invasion. 

So Many Disadvantages

“So many disadvantages!" exclaims Captain Smart, a tour guide and the captain of a tourist boat at Dunga beach. It is a phrase he will repeat again and again as he describes the impact of water hyacinth has had on his livelihood and community. 

“When water hyacinth is there, there is an abundance of mosquitos. People are getting sick...Malaria, ” he continues, “It also comes with wild animals, like snakes…that is a threat!” Watch the full interview here. 

Water hyacinth grows in thick colonies that can go on for hundreds of meters. During a full-blown invasion, navigating the water is almost impossible. Every inch forward or backwards is hard won. Motors fail as they’re entangled in plant material, leaving captains to rely on wits and prayers. 

“Nobody wants a boat ride during an invasion," adds Ashley, Captain Smart’s colleague and guide on the same boat. "The plant really affects our income when it is around.”

It's the same narrative, if not worse, for fishermen on the lake. Fishing is already an arduous and hazardous profession, especially in a region where many fishermen still rely on paddled and wind- sailed dhows. Water hyacinth makes it harder and more dangerous. 

1. It blocks out sunlight, which starves the phytoplankton that form the foundational base of the aquatic food web
2. It hinders the natural exchange of oxygen between air and water. Combined with no.1, this creates an environment where many fish struggle to survive. 
3. It can also seal off breeding and nursery grounds. Overall, effects 1, 2, and 3 reduce fish populations, forcing fishermen to travel further and longer in search of more. 
4. Rowing through mats of water hyacinth is one of the most exhausting jobs. 
5. Sometimes, there is just too much water hyacinth to sail through. So, fishermen end up being trapped out on the lake. 

What makes it scary is that mats of water hyacinth can seemingly appear out of nowhere, carried by the waves and currents, and overwhelm a vessel and its occupants. 

The Forever War

Water Hyacinth is a menace that some estimates say costs the Lake Victoria Basin $150 million each year. As such, stakeholders have been engaged in a full-scale war against the plant to try to eradicate it. No! To try to manage it. 

This is because it is extremely difficult to eradicate the plant. It reproduces too fast, migrates far and wide, and releases seeds that remain viable for up to 30 years. So, stakeholders' only hope is to manage the plants’ population using a series of biological, mechanical, and chemical measures. 

They are doing a good job so far. In our next piece, we’re going to highlight local efforts to manage the invasion. Spoiler: we’re partnering with one of these initiatives. Stay tuned to find out which one.