Drones map disastrous environmental effects of fishing in Benin

BEES, an NGO, takes authorities on a tour of Nokoué Lake and along Benin’s coastal regions to raise awareness about the environmental impacts of fishing and worsening erosion.  à ses drones.
BEES, an NGO, takes authorities on a tour of Nokoué Lake and along Benin’s coastal regions to raise awareness about the environmental impacts of fishing and worsening erosion. à ses drones.

BEES is a NGO in Benin which uses drones to capture images of environmental degradation caused by human activities. They use the images and information captured by their devices to convince local authorities to act faster to address these worsening problems.

Most of the 75,000 people living around the massive Lake Nokoué, which spreads across 339 hectares, make their living from fishing. But a growing number of fishermen and the overuse of traditional fishing techniques is now threatening the lake’s ecosystems and the fish that live there.

The lake is oversaturated with "acadja", a traditional fishing method. Fisherman drag dense masses of branches into shallow areas where the fish then gather to feed and breed, making them easier to catch. Unfortunately, this also makes navigating the lake difficult and modifies the ecosystem.

This practice is banned, but in reality the authorities do little to control it. For the past few years, BEES has been speaking out against it.


Arnaud Adikpeto is the project lead for the NGO BEES. (Photo provided by our Observer)


In November 2017, activists decided that they needed to do something drastic to convince the authorities to act. They organised three days of workshops and invited representatives from the Board of Fisheries (in French, “la Direction de la production halieutique”, or the DPH), a body attached to the Ministry of Agriculture, Livestock and Fishing.

Workshop participants worked with members of the NGO to use drones to map the lake, thus allowing them to better visualise the destruction caused by the fish parks. Project leader Arnaud Adikpeto says that the event was a success and that the authorities who participated went on to quickly address the issues.

"With a simple report, it's possible that no one would have noticed our warning”


After spending three days with our team on Nokoué Lake, authorities from the Board decided to regulate the practice of building acadjas and work to unclog the lake. We saw them removing some of these acadjas on the lake in February. Things happened fast!


The NGO BEES gave authorities from the Board of Fisheries a tour of Lake Nokoué and allowed them to view the zone through drone images. (Photo by our Observer)


If we had just released a simple report, then maybe no one would have taken our warning seriously. By inviting the authorities to see what we do, we gave them the opportunity to understand our work and to actually sit next to us, examine the aerial images and maps we created, and to assess the risks. Another proof of success: the DPH let us know that they wanted to invest in three drones to keep an eye on installations in the lake.

This image shows "acadja" fish parks on Nokoué Lake. (Photo taken with a drone and provided by our Observers)


The situation was urgent. Local fisherman are abusing this technique, which consists of putting branches and bushy plants in shallow water where fish hide, eat and reproduce. Fisherman then surround the “fish park” with a net and scoop up a large quantity of fish in one swoop.


Fisherman haul branches to create acadja on Nokoué lake. (Photo by our Observer)


But this causes problems because fisherman keep adding branches without removing the old ones. The result is that the branches rot and heaps of residue pile up. This makes the lake shallower and can destroy ecosystems and make it hard to navigate the lake.


Coastal erosion

Buoyed by its initial success, BEES now wants to work on raising awareness amongst decision-makers in other zones where the environment is being threatened by human activities.

These activists are particularly concerned about the erosion of the coastline which, according to Benin’s Institute of Oceanographic and Fisheries Research, is receding by up to 30 metres a year in some places.

Putting a halt to this phenomenon is a priority, according to the government of Benin. In 2014, the country invested €70 million to construct eight barriers to prevent sand from shifting. Each was 200 to 300 metres long.

"We map residential zones to make sure that they don’t disappear”

The problem is that these barriers also made things worse in certain areas, says Adikpeto.

The barriers built by the government improved the situation in some places, but they also just displace the problem. Erosion continues to occur but downstream of the installation.

The areas where there are no barriers (right outside of Cotonou, towards Nigeria) are now even more affected by erosion. The government claims that it is taking this problem seriously and that it will have other barriers built.

In the meantime, we’re doing everything we can to get the authorities to respond as quickly as possible. The situation is urgent! We mapped the zones under threat so that we can have images of the homes and buildings that exist now to make sure that they don’t disappear. If the government doesn’t do anything, we will come back to the area in a few months and make the same map. Then, we’ll show the relevant authorities what has happened during that time period. If it is receding 30 metres a year, things could change fast!

We are also using our aerial videos and photos to keep an eye on what is happening on the other side of Benin’s coastline, near Togo.

There is a lot of erosion happening around the "king’s mouth”: a thin strip of land that separates the sea from the Mono River. If the land disappears, then the people living there would be in trouble. It would also result in the fusion of two very different ecosystems.


This strip of land, which separates the sea from the Mono River between the towns of Grand-Popo and Ouidah, is slowly eroding away. (Photo taken with a drone)

We’ve been working in partnership with Benin’s Institute of Oceanographic and Fisheries Research. Our images support their data and make the warnings that they are giving very concrete. We also work with organisations in countries that border Benin. Our country can’t fight alone and needs to think of a regional policy.


In this video filmed by BEES drones, you can see the erosion of a strip of land known as “the king’s mouth” between 1’30” and 2’41”.

Inspire other organisations

Benin is planning on building more hydroelectric barriers. One will be constructed in Kétou, a city in the southeast of the country. The NGO is already beginning to document the region to make sure that the construction of the barrier respects the local population and environment.

Teams from BEES train members of other organisations in November 2017.


The BEES team has already trained six other environmental organisations on how to use drones, thanks to a partnership with Dutch organisation IUCN (International Union for the Conservation of Nature).

"It’s thanks to them that we were able to obtain drones", says Adikpeto. BEES is also supported by the French Global Environment Facility and the Dutch Ambassador to Benin.

Article by Maëva Poulet.