Editor’s Note: Call to Earth is a CNN editorial series that aims to collaboratively report on solutions to the environmental challenges facing our planet. Rolex’s Sustainable Planet Initiative has partnered with CNN to raise awareness and education about key sustainability issues and encourage positive action.
The Congo Basin in Central Africa is one of the largest remaining wildlife areas on Earth, covering 3.4 million square kilometres (1.3 million square miles). It is home to more than 10,000 species of tropical plants and 2,000 species of animals, many of which are endemic to the region.
As Africa’s largest river basin, it crosses the borders of many countries and is one of the world’s largest carbon sinks, absorbing and trapping carbon from the atmosphere.
Despite its importance, much of it remains undocumented by science. As temperatures continue to rise globally and weather patterns change, understanding the basin and its ecosystems is vital for scientists and local communities to protect these areas and build resilience to climate change.
Steve Boyes, founder and project leader of The Wilderness Project, is collecting scientific information along the Congo River. This is part of the Great Backbone of Africa research expedition, in partnership with the Rolex Perpetual Planet Initiative, which began in the Okavango Delta and will also explore the Zambezi, Nile, Chad and Niger river basins.
“There’s magic, mythology and power in these rivers,” Boyes told CNN. “It’s something unknown. And it’s typically around every corner of these rivers.”
Boyes has dedicated his life to exploring the science of Africa’s freshwater systems. His research in Botswana’s Okavango Delta in 2014 helped earn the river its 1,000th UNESCO World Heritage Site status and led to the discovery of more than 140 new species, as well as a new resource for the delta in the Angolan Highlands.
This expedition is not Boyes’ first exploration of the Congo Basin. In 2023, he embarked on a 39-day canoe journey down the Cassai River in Angola with a team from the National Geographic Okavango Wilderness Project, covering more than 754 kilometers (469 miles) and showing that the Munhango River is the primary source of the Cassai.
In April and May this year, the Great Backbone of Africa team worked intensively along the Congo-Zambezi watershed (a term referring to a forested watershed with high water storage potential) spanning the Chambeshi River in northern Zambia – the Congo’s most remote source. The 33-day journey upstream was the first scientific expedition to attempt to traverse the length of the Chambeshi and document its landscape and communities.
Traveling in five canoes, the 10-person team collected data on everything from birds to settlements, boats and bridges to create a comprehensive snapshot of Chambeshi’s vast ecosystem. Along with 71 aerial drone surveys, water quality measurements and pathogen samples, they took nightly recordings of bats and measured water flow to see how the river evolved on its journey across the country.
They also stopped at regular intervals to monitor fish biodiversity and sample environmental DNA (eDNA) released into the water by different organisms.
“eDNA will tell us what the water diversity is in the river,” said Matt Dooley, principal investigator of the Chambeshi expedition.
“In some of these rivers… the diversity is incredible and there are not many people in the world who really know all the fish that we collect. So we often find new species or new subspecies. And the Chambeshi River in particular is very poorly sampled in terms of fish diversity.”
The team caught, sampled and photographed around 50 species of fish, which will be sent
They need to be analyzed to confirm whether they are new species or subspecies that have not yet been discovered by science.
Once an expedition is complete, the data collected is uploaded to the cloud and made available to any researcher who wants to use it. The findings are also compiled and distributed to local authorities, NGOs and communities so they can better understand the nature of the river and where it could benefit from increased protection measures.
“It’s not just going down and taking pictures and looking and meeting people,” Boyes said. “These are the most detailed, hydrological, ecological river baselines ever done anywhere on Earth.
“We’re doing this for future scientists.”
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