Banc d'Arguin Fishing Waters

Nouadhibou · Dakhlet Nouadhibou · Mauritania

The Banc d'Arguin stretches along Mauritania's Atlantic coast like a submerged Saharan plateau, a vast expanse of shallow sandbanks, seagrass meadows, and tidal flats where the desert meets one of the most productive marine ecosystems on earth. The cold Canary Current wells up along this coast, dragging nutrient-laden deep water to the surface and fuelling an explosion of life that has earned the area UNESCO World Heritage status. Our expedition boat anchored over a seagrass bed in eight metres of water on a windless December morning. The descent revealed a landscape that felt more prairie than ocean. Turtle grass stretched in every direction, its blades swaying in a gentle current. Within seconds a green sea turtle appeared, unhurried and massive, cropping the grass with methodical bites before gliding away into the haze. The guide signalled to stay low, and we drifted over the meadow like hawks over farmland. The seagrass gave way to patches of open sand where cuttlefish hovered and shifted colour. A pair of guitarfish lay half-buried, their flattened bodies barely distinguishable from the substrate until one erupted in a cloud of silt and banked away. Schools of grey mullet moved through in disciplined columns numbering in the hundreds, their silver flanks catching the filtered Saharan light. At the meadow's edge a pod of Atlantic humpback dolphins worked the shallows. We heard them before we saw them, clicks and whistles transmitted through the water column, and then three grey shapes materialised from the green murk, passed within ten metres, and vanished. These dolphins are among the rarest in the world, and Banc d'Arguin holds one of the last viable populations. The encounter lasted twenty seconds but carried a weight that the rest of the dive could not match. On the return I paused over a spotted eagle ray resting on the bottom, its white-spotted wings spread wide, before it lifted off and disappeared with three powerful strokes.