Our knowledge of sawfishes may be limited, but we can be fairly sure that they were once far more abundant than they are today. In a bid to establish just where they occurred, where they no longer occur and where they may be just hanging on, Ruth Leeney is conducting interviews with artisanal fishers – and in Madagascar has found ‘the king’.
At first I thought nothing of it. Distracted by the task ahead – setting a net 100 metres (330 feet) long, just before midnight – I assumed that the moon was full and busied myself with disentangling the net and checking the floats, grateful for the pale gleam that surrounded us. But the sky was dark; it was the sea glowing all around, green and blue, as if lit from below by a huge spotlight. As the boat picked up speed, the water dancing off its bow looked like sparks of blue fire. Laughing in delight, I dipped my hand in the water and brought up droplets of glittering turquoise. At that moment, we were a tiny bubble of phosphorescence in a sea of darkness.
Mahajamba Bay is a huge, jellyfish-shaped bay on the north-western coast of Madagascar. Its shores are hard to reach: over land, it takes several uncomfortable days in public transport from Majunga, the nearest large town. A sail boat is faster, but more precarious. This relative isolation might, I hoped, have offered the region some protection from overfishing and the exploitation of resources such as mangrove timber. However, in my conversations with local people it became apparent that activities far inland, in parts of this great red island where the local people have never even seen the sea, were having an impact on the communities and ecosystems of Mahajamba Bay.
Two rivers, the Sofia and the Mahajamba, flow into the bay, but local fishermen told me that in recent years the mouth of the Sofia has become too shallow for their boats, preventing them from entering the river to fish. I heard similar stories from fishers along some of Madagascar’s other major rivers, too. This siltation – the accretion of sediment at the river mouth – is probably due to erosion occurring far upriver. Erosion is a natural phenomenon, but has been accelerated in recent decades by deforestation and intensive farming practices. International aid and development agencies have described Madagascar’s erosion rate as one of the highest in the world. Even far out in the bay, the water around us was the colour of hot chocolate, not at all the tropical azure I had imagined the Indian Ocean to be.
Based in one of the world’s most unusual and unexplored ecosystems, Ruth aims to unravel the mystery of Madagascar’s sawfishes. Which species are present? What threats do they face? Can communities be convinced to protect them?