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Kai harvest in a Fijian river, 2022

Story from a Fluid Field by Johanne Tarpgaard

Aku, a young man from the village, finds the bamboo raft that is tied to a tree at the riverside and brings it closer to us. It is made of ten bamboo poles that are tied together with plastic wire and rope. On it lies a big white bag filled with sand that is attached to the raft using a longer rope. We climb onto the raft and, with a bit of balancing effort, Mally, I and our two white 20-liter buckets are ready to find and harvest the species that she is focusing on in her Masters in Marine studies.

Aku gets a good grip of the bamboo pole in his hand and pushes us away from the riverbank. Slowly but steadily he pushes us up the river, staying as close to the riverbank as possible to avoid the strong current in the middle. Most of the raft is underwater, so we only just stay afloat. As we move up the river, I am filled with a gratitude of feeling at home in this fluid world that I am conducting fieldwork in. I feel safe and comfortable on a barely floating bamboo raft, because I know that I have practiced being in and on the water most of my life. But I am also filled with sadness. In between the branches, grass and the reeds, plastic items of all kinds are captured. Plastic bottles, lids from different food containers, black plastic garbage bags filled with possibly even more plastics, noodle packaging and items that I can recognize as plastics but whose purpose I cannot identify.

We spend the day harvesting kai (Batissa violacea) - a freshwater mussel that lives in larger rivers in Viti Levu, Fiji. Kai spend their lives in the benthic zone where water and the sand meet, and they get their sustenance from filtering the water around them. They are a sentinel species for understanding more about microplastics in the river systems of Fiji, which is the reason why we are harvesting 150 of them today. Kai are also one of the main sources of protein and income for many indigenous iTaukei communities. At low tide, women and men go out into the river on rafts or smaller boats, and by either diving down and collecting them with their hands or by standing in the river and using their toes to collect them they harvest the kai of the day. In some villages, three quarters of their income depends on kai harvest. Aku’s village, where we harvest kai today is thus not one of them, as a sand-dredging company are based here, giving jobs and income to the community. Kai are therefore only harvested a few days a week.

After having pushed us alongside the riverbank, Aku turns the raft towards the center. As we reach the middle of the river, Mally drops the big white bag. The weight of the bag works as our anchor, helping us to stay more or less in the same spot. Mally measures the depth with the bamboo pole. It looks like it is 2–3 meters deep. “How many kai can you take in one dive?” I ask Aku, to get a sense of how difficult or easy it is to harvest kai. “Five, six, seven,” he says and smiles. I put on my snorkel mask and ask Aku if I can follow him down to see how he harvests kai, but before I am ready he dives down, the muddy water making it impossible for me to spot him. A few seconds later I see the top of his head breaking the surface and his hands filled with kai. He shows them to us before he puts them in one of the white buckets. “How do I do it?” I ask. “You just feel with your hands,” he says and smiles to me. I take a breath and dive down.

I can hardly see my hands in front of me in the muddy brown water. The current is stronger than I expected but I quickly glimpse and reach the bottom where I move my hands in circular movements in the sand. I touch the first one. It feels like a stone lying in the top layer of the sand. Right next to it there is another one. I can feel them - they are everywhere! I quickly take four or five and make my way back to the surface. The current has pulled me a few meters behind the raft, so it takes a few strokes to get back. “They are everywhere!” I tell Mally. I am surprised by how many there are, and how easy they are to harvest. I give the kai to Mally, pull myself along the raft and as I reach the front, I take a breath and dive. Once again, I reach the bottom quickly, and by moving my hands from side to side I am easily able to take three to five in each hand before the current pulls me back and I need to go up for air.

After having spent less than an hour in the water, we have more than the 150 kai we were aiming to harvest. My excitement for the kai harvest, have made me pay little attention to the surroundings, but the strong current has pulled us closer and closer to the sand dredging machine. In amidst of ruination of the riverbed, Kai still lives in large numbers side by side with humans, sand dredging machines, plastics of all kinds, fishes and entities that I still need to learn about.



Lako, J., Kuridrani, N., & Sobey, M. (2019). Freshwater Mussel (Batissa violacea) Fishery and its Value in Fiji. The Journal of Pacific Studies, Volume 39 Issue 1.

Barrientos, E. E., Paris, A., Rohindra, D., & Rico, C. (2022). Presence and abundance of microplastics in edible freshwater mussel (Batissa violacea) on Fiji’s main island of Viti Levu. Marine and Freshwater Research, 73(4), 528-539.