26
Sep
Africa’s Resilient Refusal of Agrochemicals Offers a Lesson in Tackling Invasive Species
(Beyond Pesticides, September 26, 2023) In Ethiopia’s Bahir Dar, where Lake Tana feeds into the Blue Nile, a major hydroelectric power plant stands, serving as an emblem of the ecosystem services the river provides to over two million inhabitants. Yet ever since its first appearance in 2012, this crucial waterway has been under attack by one of the world’s most invasive species: the water hyacinth.
In America and Europe, where agrochemical giants such as Bayer and Syngenta are headquartered, such problems might quickly be remedied using herbicides. However, the prevailing ethos coming from the African continent is quite different. Dion Mostert, whose South African boat business has suffered due to the water hyacinths infestation, encapsulates this sentiment, saying he has considered herbicides but sees them as a temporary fix to a much larger challenge.
Instead of relying on temporary—and often harmful—agrochemical solutions, Ethiopia and other African countries are embracing holistic and sustainable solutions.
For instance, Lake Victoria–a water body shared by Kenya, Tanzania, and Uganda—suffered from a water hyacinth infestation in the 1990s. In response, scientists introduced two species of weevils known to be natural predators of the hyacinth: Neochetina bruchi and Neochetina eichhorniae. The initiative was extremely successful, with a 90 percent decrease in hyacinth cover. This strategy was so fruitful it continues to serve as the blueprint for many other African countries facing similar infestations. Following the victories observed in East Africa, Benin mirrored this biological strategy to combat their own water hyacinth issues, reaping similar benefits.
And now, as South Africa tackles a growing water hyacinth problem, they are turning to weevils once again, denoting another chapter in a broader African tale of ecological resistance.
On the other hand, Ethiopia has adopted mechanical removal as a primary control method. In several organized campaigns, over 200,000 individuals, ranging from students to farmers, have contributed their labor to the cause by removing hyacinths by hand and building harvesting machines. While the issue has been ongoing, there have been many victories along the way. According to a study by Minychl G. Dersseh, et al., there has been a notable decrease in the expansion rate of water hyacinth. In 2016, the expansion rate was 120.5 percent, but by 2019, that number was reduced to 23 percent, reflecting the effectiveness of the persistent efforts of the community. And in November 2020, those efforts persevered in the form of a month-long initiative that aimed to clear 90 percent of the weed through physical removal.
As nations across the world grapple with invasive species like the water hyacinth, Africa’s approach offers a unique perspective. Not only is there an overwhelming desire to employ ecologically-sound solutions, but there also is an ever-growing push to address root causes rather than symptoms. While the water hyacinth was once thought of as a nuisance to Lake Tana, the plant is now gaining recognition as a potential resource. Instead of disposing or burning the biomass after removal, there is a growing push to repurpose it into fertilizer and feedstock. Officials like Ayalew Wondie, PhD, seek to engage with the issues more deeply. “The problem isn’t Lake Tana,” Dr. Wondie says. Rather, the issue is the excessive levels of phosphorous and nitrogen that make their way into the lake through agricultural runoff and poor wastewater management. Plans to create an integrated watershed management system for Lake Tana are underway at Bahir Dar University.
Despite the nuances of the many ecological systems found on the continent, globally, there is a tendency to simplify Africa’s ecological strategies, often relegating them as less sophisticated than alternative industrialized methods. Prominent politicians and corporations like the Bill and Melinda Gates Foundation emphasize Africa’s need for a green revolution. Yet, historically, these prescribed interventions deliver poor results.
In Burkina Faso, the adoption of genetically modified Bt cotton was initially seen as a revolutionary step toward achieving higher yields and combating pests. However, cotton quality was compromised over time, with the cotton fiber becoming shorter and less valuable. The economic promise it once held started waning as farmers grappled with declining revenues and increased seed costs. Even without considering the shortcomings of the cotton fiber length, the high susceptibility rate of Bt crops to insect resistance indicates further issues would have arisen in the cotton crop. Meanwhile, in Ethiopia, the fight against relentless locust invasions led to the extensive deployment of insecticides between 2019 and 2021. While these chemicals offered short-term relief against the swarms, the consequences for the broader ecosystem were profound. Widespread use of these insecticides resulted in the inadvertent death of an estimated 76 billion honey bees. Not only did the insecticide kill bees critical for pollination, but their loss also affected the livelihoods of countless beekeepers, further exacerbating ecological and economic problems.
These instances serve as stark reminders that solutions anchored in industrialized agricultural practices often introduce new challenges, undermining the very objectives they aim to achieve. This critical understanding is held by many in Africa, which is why it has sustained several ecological successes even in the face of invasive species like the water hyacinth.
As the global community confronts a changing climate and its impacts, a pressing need to reevaluate reliance on agrochemicals is needed. While these chemicals are still widely promoted as quick fixes, such methods’ long-term viability and sustainability are in question. Instead, a more holistic, ecologically balanced strategy may be the key to sustainable progress.
The African approach to the invasive water hyacinth symbolizes a mindset that might be a solution to issues of sustainability worldwide. For example, in the U.S., numerous health conditions are linked to pesticide and herbicide exposure, so making a transition away from these chemicals is crucial for the well-being of both the environment and the greater community. Beyond Pesticides offers resources to help attain these ecological goals. Consider supporting organic land management and championing pesticide-free parks and lawns in your community. If you are dealing with an invasive species outbreak, please refer to our ManageSafe™ database as a resource for best management practices for handling pests.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
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September 27th, 2023 at 9:34 am