Journey to the Center of Gabon

Scientists Will Help Inform the Country's Development and Conservation Decisions 

When you have as much water flowing through your lands as Gabon does, it makes sense to make the most of it. Although rich in oil, this Central African rainforest-covered nation has big plans to harness the power in its rivers to boost its renewable electricity production: Dozens of new hydropower plants are planned in the coming years.

But will this major infrastructure development spell disaster for Gabon’s incredible biodiversity? In the rush to progress, would ecological damage be done that later could not be undone? Luckily, Gabon’s government recognizes the importance of protecting its natural resources and is supporting science that will help it make the best decisions environmentally as it advances economically.

A team of Gabonese and American scientists gathered by The Nature Conservancy spent nearly two months methodically sampling fish species in a series of rivers whose flow might soon be affected by new hydroelectric dams. The results of their findings will be shared with Gabonese authorities as they move forward on their hydropower expansion. It's critical science. But it's far from easy.

More than 80 percent of Gabon is covered in rainforest, from its far interior to its Atlantic Ocean beaches, where elephants and gorillas appear from the treeline and hippos surf the shore. That forest is drenched by more than 120 inches of rain a year that flows along a latticework of ever-larger tributaries into ever-mightier rivers. The government aims to harness the green energy in those rivers with up to 30 new hydropower plants. 

The central African country is rich in oil, but still has a way to go to lift all of its 1.7 million people out of poverty. The World Bank calculates that almost a third of Gabon’s citizens live below national poverty lines, and only one in four living outside of towns and cities has reliable electricity. Development elsewhere in Africa has often been rushed, bringing quick benefits at great environmental expense. Gabon is trying something different. 

It is working with its scientists and others from around the world to really understand critical aspects of the ecosystems that will be affected as it accelerates along its path to development. What really is the biodiversity of that area of forest where a logging license might be approved? How healthy are the offshore fisheries, and would it help to put some off-limits? And, in its freshwater rivers, what species lie beneath the surface, and how might a new hydropower dam built right there affect them? 

The Nature Conservancy has gathered six scientists to spend weeks deep in the Gabonese rainforest to help come up with this data. Led by Jean-Hervé Mve Beh, from Gabon's National Research Center, and Dr. Brian Sidlauskas, associate professor and curator of fishes at Oregon State University, the team is mapping all species they find in a series of rivers that might be dammed. "We're creating the baselines," says Jean-Hervé. "Our work is a recognition of the trend to better understand the impact of human activity on natural habitats." (From left: Joe Cutler, Franck Nzigou, Hans Mipounga, Jean-Hervé Mve Beh.) 

This is relentless, challenging work in remote places where conditions demand extraordinary energy and patience. An hour's thunderstorm can flood camp and leave everything wet for days. The fish they study are most active at night, which means venturing into the water half-a-dozen times from sunset to sunrise to check nets and collect samples. Each step of the way, no matter the difficulties, everyone must stick to the precise methodologies and strict protocols demanded by global science and the panels that will review the findings. 

Samples of fish are collected with many types of nets: nets whose mesh tapers along their length, left hanging in the river's flow; nets as dense as lace curtains stretched between poles, like on a volleyball court; and nets that are hand-held scoops, like the ones kids play with at the beach. More serious tech is deployed, too. Electricity pulsed through shallow streams stuns tiny fish that might otherwise be missed. To avoid being stunned themselves, the team wears thick brown neoprene waders and orders everyone nearby to keep clear of the water. 

The samples must be logged, assessed, and in some cases analysed daily, according to a strict regimen set by Brian Sidlauskas, who directs the science on the expedition. To do this, the team sets up a makeshift mobile lab every time they set up camp, which mostly means somewhere deep in the forest. Here, in Fougamou, the team is in town and enjoying the relative comfort of a few nights at a local hostel. The lab — luxurious compared to other sites — is in the hotel's new outdoor pizza kitchen.

A similar TNC-led expedition in 2014 led to the discovery of a new genus of fish called Cryptomyrus. Joe Cutler, a graduate student at the University of California, Santa Cruz, reckons this team might be on the trail of at least one new species so far. He's using an oscilloscope to measure the electrical signals emitted by mormyrids the team found on a river called the Grand Bondolo. One particular fish, otherwise indistinguishable, communicates with a small but significant kink in the wave its pulse makes on the screen. "That little bump could be enough to mark a new species," Joe says. 

There's a long way to go before anything as headline as that can be declared. Samples, photographs, and notes were shipped back to Oregon State University, where Brian will lead the analysis of what was found. Several members of the Gabonese team will also be traveling to Oregon to assist him in the laboratory.  "It's an age of discovery here," he says. "There's so much basic science coming out of this, so much basic biology. And it's fantastic that it will be used to help decide whether this dam site or that dam site is better or worse ecologically, or whether this dam design or that dam design is better."

The study's results will provide critical input to the planned hydropower expansion, and help inform decisions on where best, and how best, to build. TNC will continue to work with the Gabonese government to supply data and studies that can help it choose the most sustainable path to achieve its development goals in ways that will safeguard the country's extraordinary biodiversity. 


Gifts of any size designated to Gabon will be matched 1:1 by a generous member of TNC’s Board of Directors. To find out more, contact Lauren McFarlane at


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