On the Içana River, a giant otter can crack a fish’s bones on the bank while Baniwa fishers check traps just downstream. The two groups meet often in northwestern Brazil, yet their relationship has remained largely peaceful.
The river flows into the Rio Negro, a major Amazon tributary known for dark, naturally acidic water. Fish are not especially abundant there, but they are the main source of protein for Baniwa people living along the river and its tributaries near the Colombian border. Giant otters and neotropical otters also hunt in these waters. In other parts of the Brazilian Amazon, fishers have blamed otters for eating valuable fish, driving fish away and damaging nets. Such tensions have sometimes led people to kill the animals.
A 2026 study led by ecologist Natalia Camps Pimenta offers a different picture from the Upper Rio Negro Indigenous Land. Pimenta and her colleagues interviewed 19 Baniwa fishers in seven communities along the middle Içana River. Eighty-four percent said they regularly encountered otters while fishing in the dry season. But only 32% described otters as competitors; nearly two-thirds did not see them that way.
The researchers point to a mix of beliefs, habits and history. For many Baniwa, otters are “pajés das águas,” or spiritual guardians of the waters, believed to protect fish and aquatic life. Fishers and neotropical otters may use the same grounds, especially in lakes, while giant otters were less associated with the places Baniwa fishers preferred. People also make room for one another by avoiding certain spaces at times, targeting different fish and changing their behavior.
That relationship has not always been easy or unchanged. In the mid-1900s, commercial fur trading involving local communities sharply reduced populations of both giant and neotropical otters. The trade disrupted a bond shaped over generations by Baniwa knowledge and culture. The researchers say today’s coexistence reflects not just spiritual beliefs or efforts to avoid clashes, but also past experience, changing social arrangements, outside pressures and the river environment.
The findings matter because they challenge the idea that people and wildlife must always compete for the same food. In a place where fish are scarce and encounters are common, most of the fishers interviewed still did not label otters as rivals. As ecologist Jansen Zuanon told Mongabay, the animals are “almost impossible to ignore”—but being noticed does not automatically mean being attacked.
The study suggests that coexistence grows through practical choices as well as cultural ties: where people fish, what they catch and when they give animals space. The Baniwa experience offers a reminder that local knowledge and a community’s history can shape how wildlife is treated. Understanding those relationships may help inform efforts to protect otters and the people who depend on the same rivers.