Fredrick Mugira, Bertha Fellow
Two small rivers in western Uganda: Mpanga, and Rwizi, are choking on plastic waste, carrying it to lakes that drain into the River Nile. Once in the Nile, this plastic debris may flow into the Mediterranean Sea.
Mpanga River traverses Fort Portal, a city of 52,911 population, picking up all sorts of waste, including plastics. Swiftly snaking in hilly terrain, as its name suggests, River Mpanga flows into Lake George through Lake Edward and outs to Lake Albert through Semliki River. The three lakes drain into Albert Nile.
A marine plastic pollution consultation workshop organized by the Nile Basin Initiative in April 2022 in Entebbe, Uganda, heard that the hilly terrain of Fort Portal city “makes it more probable that uncontrolled plastics drain into this river (Mpanga).”
Equally, River Rwizi meanders through Mbarara city, inhabited by over 120,900 people, picking wastes, including plastics, on its journey from the mountainous district of Buhweju. It drains into the wetlands leading to Lake Victoria, the source of the Nile.
Mbarara city generates 36 metric tons of municipal solid waste per month. Of this, 1.6 metric tons is plastic waste. This is according to a draft report on plastic waste transport from the Nile River and its major tributaries into the marine environment discussed at the Entebbe marine plastic pollution consultation workshop in April 2022.
According to the same report, Uganda’s tourism city of Fort Portal generates 28 metric tons of municipal solid waste per month; of this, 2.4 metric tons is plastic waste.
A large volume of plastic waste, primarily used soft drink bottles, generated from Fort Portal city drains into River Mpanga, a source of domestic water for over 60,000 dwellers of Fort Portal city and neighboring areas.
Journalist Sunday Rogers, who has covered the Mpanga river pollution story for over a decade, estimates that “daily, 500-1000 pieces of plastic bottles find their way into River Mpanga.” And he recounts that the situation is worse during the rainy season.
According to the UN environment programme, “one million plastic bottles are purchased every minute” worldwide. Half of these are designed to be thrown away after a single use.
The number of plastic bottles from Mbarara city that drain into river Rwizi daily is also in the “thousands,” according to Jeconious Musingwire, the southwestern region manager for the national environment watchdog, NEMA.
“Some contain contaminated liquids which pollute the river’s water,” laments Musingwire.
Although the two cities have official waste dumping sites: Kenkombe for Mbarara city and Kiteere for Fort Portal city, due to the rural nature of these urban centers, plastic waste, just like other wastes, is discarded into the environment.
Other sources of the plastics
Rivers Mpaga and Rwizi are not the only sources of plastic waste in Uganda’s lakes that drain into the Nile; some originate from factories and urban centers adjacent to them. Others come from fishers.
For example, areas that fringe Lake Victoria and river Nile, such as Nakawa division, Central division, Bweyongerere, all in Kampala city; the Entebbe municipality, and Jinja city, have a “relatively substantial plastics leakage risk” according to the NBI’s draft status report on plastic waste transport from the Nile River and its major tributaries into the marine environment.
Streams and the drainage channels that drain through such urban centers and their industrial parks pour much plastic debris into the adjacent wetlands leading into Lake Victoria or the river Nile.
Nakawa municipality alone has three streams that drain into Lake Victoria. They meander through three industrial parks before emptying into Lake Victoria through the Kinawataka wetland.
In western Uganda and eastern Democratic Republic of Congo, streams and rivers from the nearby urban centers such as Kasese municipality, Katwe town on the Uganda side, and Vitshumbi on DR Congo drain plastic debris into Lake Edward. The same happens to Lake Albert as streams and rivers from adjacent urban centers such as Kanara town, Hoima city on the Uganda side, and Parombo, Tchomia, and Kafe towns on the DR Congo side flow into it.
Dr. Vianney Natugonza, a fisheries expert and senior lecturer at Busitema University maritime Institute, says plastics are “always glaringly visible” in some rivers draining these lakes.
The use of plastic fishing floaters on these lakes by fishers is also a significant source of plastic debris.
For instance, at Lake Kyoga’s Zengebe landing site in Rwampanga town council, there are 70 fishing boats. Each boat usually has two fishers carrying 40 fishing nets tied together for a fishing trip. At the lower side of the long net, the fishers tie at least five sand-filled small fishing sinker bags made from plastic. These help the net to sink. But they also need the same net to float. So they tie more than five empty plastic bottles on its upper side. Some of these plastic materials sink in the lake when they get off the nets or wear out, although the landing site’s chairperson, Wajja Alex, says they “regularly collect them and burn them.”
The situation is not different at lakes Edward and George, where fishers still employ used plastic bottles and pieces of plastic sandals to enable their nets to float.
The introduction of plastic waste in lakes that drain into the river Nile inescapably washes such debris into the Nile.
According to Dr. David Were, a water quality researcher and lecturer at Makerere University, Kampala, for flowing systems such as rivers, when a pollutant is introduced upstream, it or some of its components are most likely to be transported downstream.
And this is more common to pollutants that cannot easily segment at the bottom of the river, such as plastic waste, which floats.
From inland to the Sea
River Nile, the longest river in the world, travels a distance of 6,695 kilometers from Lake Victoria in Uganda, through South Sudan, Sudan, and Ethiopia to the Mediterranean Sea via Egypt. According to the Nile Basin water resources atlas, lakes Victoria, Kyoga, Edward, Albert, and Tana are the major natural lakes of the Nile.
Rivers are “direct conduits of trash into lakes and the oceans,” according to the UN environment programme, which argues that “rivers and lakes carry plastic waste from deep inland to the sea, making them major contributors to ocean pollution.”
It takes approximately three months for the waters near the town of Jinja, Uganda — the point where the Nile leaves Lake Victoria, to reach the Mediterranean Sea, according to Laban Musinguzi, a fisheries scientist at the National Fisheries Resources Research Institute (NaFIRRI) who is also the editor for freshwater biodiversity portal.
For floating plastic debris to travel all this journey, the waterway must be free of flow alterations and obstructions. But tiny particles may furtively sift through.
“But if you look at the case of river Nile, we have many flow abstractions, for example, we have hydropower plants, which screen and trap objects in flowing in the water before reaching the turbines,” narrates Dr. Were.
“So when you are talking about plastics flowing downstream, these should be small particles,” says Dr. Were. He cites mesoplastics ranging from 5–10mm long and microplastics that are less than 5mm long.
These “can be able to flow through the turbines and flow downstream, affecting the health of the people depending on the water downstream,” narrates Dr. Were.
According to the National Oceanic and Atmospheric Administration’s National Ocean Service, microplastics are the most common type of debris found in the oceans.
Is the Nile exporting Uganda and DR Congo’s plastic waste to Mediterranean Sea?
A study by the Helmholtz Centre for Environmental Research in Germany found that 95 percent of the plastic waste transported by rivers into oceans and seas comes from ten rivers. The list of these rivers includes the Nile, which drains into the Mediterranean Sea.
The Mediterranean basin’s annual plastic waste input is estimated at 100,000 tons. Up to 50% comes from land-based sources, 30% from river channels, including the Nile, and 20% from maritime transportation.
Callist Tindimugaya, Uganda’s commissioner for water resources planning and regulation in the ministry of water and environment, acknowledges that the plastic debris in Africa’s great lakes wash into the Nile and flows downstream. He, however, believes they may not easily reach the Mediterranean Sea.
“We have several wetlands that will hold them,” he narrates.
According to the Nile Basin Initiative, there are about 17 major wetland systems in the Nile basin. These include South Sudan’s Sudd, the most extensive wetland in Africa and the second largest in the world, covering an area of 57,000 square kilometers. Others are the 542 square kilometer Lake Bisina Wetland System in Uganda and the Dinder National Park wetland system in Sudan, which covers an area of 10,846 square kilometers.
Such wetland systems trap and hold the plastic debris, causing more challenges, according to Dr. Tindimugaya.
“In the areas where we have plastics, we have much flooding because they block water,” he relates, further expressing worry that “we do not have to worry about plastics reaching the Mediterranean sea alone; by the time they reach South Sudan, what damage will they have caused even on the Ugandan side?”
What is more worrying is that microplastic deposit in riverbeds has long-term retention; they remain within riverbeds for up to seven years before moving to the seas and oceans, according to a study by researchers at Northwestern University and the University of Birmingham in England.
Based on this evidence, the more time plastic debris lingers, the more effect it has on an ecosystem.
A 2019 study published in the journal of Environmental Science and Technology found that an average person eats at least 50,000 particles of microplastic annually. Most of these particles were found in rivers, oceans, soil, and air.
“Individuals who meet their recommended water intake through only bottled sources may be ingesting an additional 90000 microplastics annually, compared to 4000 microplastics for those who consume only tap water,” warned the study.
River Nile is a lifeline for over 272 million people who live within its basin, according to the Nile Basin initiative. Most depend on the Nile’s water and other resources, such as fish.
Unfortunately, over 75% of fish sampled in a study on Evidence of Microplastic Contamination in Fish from the Nile River contained microplastics in their gastrointestinal tract. The highest number of Microplastic was found in the Nile Tilapia.
The impacts of humans ingesting microplastic are severe. Plastics contained “over 10,000 chemicals” linked to “increased cancer, infertility, decreased penis size” in humans, according to Bethanie Carney Almroth, associate professor and researcher at the University of Gothenburg. Bethanie spoke at the 2022 virtual training sessions on water and communications facilitated by the Stockholm International Water Institute.
Simply put, “preventing plastic waste discharge into any water system right from their source is the best way to stop plastic pollution from going downstream a river,” narrates Dr. Were.
The story was first published by waterjournalists.com