Papua New Guinea is known for its multitude of tribes and languages – more than 800 of the latter, each called the tok ples (talk place) of a certain area and group of people. Simarun, shigat, simie, warame, woreman, waruman, uruman… As we moved from village to village, the name for sawfish changed, but everyone had caught sawfishes recently and confirmed that they were present in the Sepik River year-round. But after years of hearing the stories of old fishermen, I wanted proof. I was looking for living sea monsters.

When we reached Kopar, a village at the mouth of the mighty Sepik River, the locals told me that they caught sawfishes – uruman in their tok ples – every day, just beyond the river mouth. They invited me to join a group of fishermen the next morning to watch them retrieve their nets. They assured me there would be a sawfish in the catch. In years of searching, this was the most confident assertion I had heard; I needed no further encouragement. And so, after a night of broken sleep on the floor of a local house, I climbed into a boat in the pre-dawn shadows and held on tight as we crossed the churning waters where the muddy flow of the river met the blue of the ocean.

Just beyond that tumult, the fishers hauled in their 200-metre-long (650-foot) nylon nets, dexterously untangling one baby shark after another and dropping them onto the deck. I was momentarily distracted by small winghead sharks, like little aliens emerging from the depths. Keeping my toes clear of the heaps of net on deck, I held my breath and waited.

The first net brought up no sawfish. I wondered – have I come all this way to document the sea monster’s demise even in this far-flung corner of the earth? And then, in the second net, a reddish glint in the sun, an erratic thrashing of something long and ungainly. A narrow sawfish! With an iridescent purple gleam to its skin, it lay on the deck like a jewel pulled up from the seabed. I held its tail while Jerry, the chief fisherman, expertly extricated the fish’s saw from the snarls of net. There was fight in this little creature, so I worked quickly, taking measurements and photos, and then released it back to the sea. It disappeared under the waves, allowing me barely a moment to absorb that finally, after five years, I had found living proof of the existence of sawfishes in a place where no one had ever looked. The fishermen were nonchalant; I was beaming.

In the five nets we checked that morning, there were two narrow sawfishes, both just over a metre (three feet) in length. Adult narrow sawfishes can reach 3.5 metres (11.5 feet), so these were young animals. When we got back to Kopar, we were told that another boat had caught a bigger sawfish that same morning and I was handed the animal’s saw, still bloody where it had been cut from the head, as proof. It was a largetooth sawfish, probably about three metres (10 feet) long based on the length of the saw. I hurried along the beach to where the team of fishers had landed the animal, but it had already been reduced to chunks of flesh. Its large, golden fins were laid out on a wooden rack to dry in the sun. Once dried, they would be taken down the coast to the nearest town, where shark fin traders would buy them and ship them to Asia.