There is a stretch of Mauritanian coast, roughly 200km north of Nouakchott, where the Sahara meets the Atlantic with almost no transition. There are no cliffs. There are barely any trees. The dunes simply walk into the sea. On this coast, in a handful of small villages built mostly of wood and bone, live the Imraguen people — perhaps two thousand of them, depending on how you count — who have been fishing these waters for generations in a way that exists almost nowhere else in the world.

The Imraguen are not a large group. They speak a Hassaniya-influenced dialect, with words borrowed from Berber and from earlier coastal languages. They have lived on this coast since at least the 16th century, possibly much longer. And they are the only human community formally permitted to fish inside the Banc d’Arguin National Park, a UNESCO biosphere reserve that covers around 12,000 square kilometres of Mauritania’s coastal waters and dunes.

The fishery, and what makes it strange

What the Imraguen do is, at first glance, simple. In autumn and early winter, vast schools of yellow mullet — locally called “courbine” though the species is debated by ichthyologists — migrate along the Mauritanian coast. The Imraguen wade into the shallows with hand-thrown nets and catch the fish in large numbers.

What they don’t do is use boats with engines. They don’t use commercial trawls. They don’t, traditionally, fish offshore. The technique that makes the Imraguen famous involves a cooperative relationship with bottlenose dolphins, which drive the fish schools toward shore. When the dolphins arrive, the Imraguen wade in. The dolphins eat the fish that escape the nets. Both species benefit. The relationship is the only documented case in the world of a wild marine mammal cooperatively fishing with humans on a regular, structured basis.

This is not folklore. It is observed, repeatedly, by scientists. There’s a good overview on Wikipedia of the community and the practice, and the cooperative fishing has been written about in journals as far back as the 1960s. What’s unclear is how the relationship began. The Imraguen say their ancestors taught the dolphins. Marine biologists are less certain. What’s beyond dispute is that the practice exists, and that it depends on both the dolphin population and the fish migration continuing in patterns that have held for centuries.

The Banc d’Arguin

The reserve itself is one of the largest and most ecologically important protected areas in West Africa. The shallow waters support an extraordinary density of fish, which in turn support migratory shorebirds — millions of them, every winter, from Northern Europe and Siberia. Walking along the dunes in November, you see flocks of dunlin, knot, oystercatcher, redshank, gathering in numbers that look impossible. The reserve is, in essence, the most important wintering ground for Palearctic shorebirds in West Africa.

The UNESCO inscription for the site emphasises the contrast — desert and sea, terrestrial and marine, almost no transition zone. It also emphasises the human dimension. The Imraguen are not an artefact of the reserve. They are a living component of it. Their fishing practices are part of what the reserve protects.

The pressures

The Imraguen way of life is under several pressures simultaneously.

The most obvious is industrial fishing offshore. Mauritanian waters are some of the richest in West Africa, and foreign trawlers — Chinese, European, Russian — have been operating in the country’s exclusive economic zone for decades. The Banc d’Arguin’s protected area excludes them from a 12,000-square-kilometre zone, but the surrounding waters are heavily fished. The pelagic species that migrate through the reserve also migrate through fished waters. What happens outside the boundary affects what happens inside.

The yellow mullet runs, by local report, are not what they once were. Some years the fish arrive late. Some years they don’t arrive at all in some villages. Whether this is climate change, offshore overfishing, or natural variability is a question that fisheries scientists and the communities themselves continue to discuss.

The second pressure is economic. Imraguen households are poor by any standard, and younger generations are increasingly leaving for Nouakchott and beyond. The skills required for the traditional fishery — the wading, the net throwing, the deep knowledge of fish behaviour and dolphin patterns — are not easily transmitted to someone who’s been in the capital for a decade. Several villages have shrunk noticeably over the past twenty years.

The third is climate. Sea temperatures along the Mauritanian coast are rising. The cold upwelling that brings nutrients to these waters depends on patterns that may or may not hold. There’s discussion in the literature — see some of the West African oceanography work FAO has published — about whether the productivity of the entire region could shift northward over coming decades.

What the future might look like

Honestly, I’m not sure. The Mauritanian government has, in fits and starts, supported the Imraguen — both because the community is culturally distinct in a country that values its diverse traditions, and because the Banc d’Arguin is a source of international prestige and conservation funding. The reserve management is generally serious. The community-level engagement varies by village.

Some Imraguen have begun engaging with eco-tourism, in a careful way. A small number of visitors are permitted into the reserve each year, often with Imraguen guides. The income is modest but stable. Whether this becomes a meaningful economic floor for the community, or whether it eventually corrupts the practices that the tourists came to see, is the question every protected area faces eventually.

The dolphins, for their part, continue to show up. There’s something genuinely moving about watching a fishing event unfold — the men in the water with their nets, the dolphins arcing through the shallows, the fish caught in the convergence of two different ways of hunting that, somehow, work together. It is not a relationship that we engineered. It is not a relationship that fits neatly into modern fishery management.

It existed before we noticed it. It will continue to exist, or not, on its own terms. Our job, mostly, is to keep the surrounding world from pulling it apart. That’s a more limited brief than conservation usually claims for itself, but in the Banc d’Arguin, it might be the most honest one available.

— the editors