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Underwater heist: Rare footage exposes dolphins' fishing net raids
In a series of unprecedented underwater images, photographer Thomas Peschak has captured Amazonian pink river dolphins piercing fishing nets to steal catfish-a behavior never before documented in such detail. The 2023 photographs, taken in the murky depths of Brazil's Rio Negro River, reveal the dolphins' agility as they exploit fishermen's catches, a tactic that has long frustrated local communities but remained largely unseen by outsiders.
The thief of the Amazon
Peschak, a marine photographer with over two decades of experience, described the dolphins as "great thieves," capable of maneuvering with "incredible exquisiteness" around nets. The animals have learned to associate the sounds of fishing boats and the sight of nets with easy meals, he noted. "No one had ever dived to photograph this behavior underwater," Peschak said, highlighting the challenges of navigating the Amazon's opaque, uncharted waters. His work later earned the photojournalist story award at the 2024 Wildlife Photographer of the Year competition.
The pink river dolphin-known locally as boto in Portuguese and bufeo in Spanish-is the world's largest freshwater dolphin, reaching up to 2.5 meters (8.2 feet) in length and weighing as much as 200 kilograms (440 pounds). Its distinctive melon-shaped forehead, rose-tinged skin, and 100-toothed snout belie a highly intelligent creature that uses echolocation to navigate the Amazon's labyrinthine waterways. Yet despite their cultural significance, all four species of Amazonian river dolphins are now endangered, threatened by hunting, pollution, drought, and fatal entanglements in fishing gear.
Folklore and conflict
Indigenous communities across the Amazon have long woven the boto into mythology, depicting them as shape-shifting seducers or guardians of underwater cities. But their reputation as thieves-of fish and, in some tales, of women-has fueled hostility. "There are communities where fishermen will actually kill these dolphins out of revenge," Peschak observed during his two-year National Geographic expedition across the Amazon Basin. The conflict is exacerbated by accidental bycatch and propeller injuries, with marine biologist Fernando Trujillo estimating that over 700 dolphins die annually in Colombian waters alone due to net entanglements.
"The nets are our main concern. Every year, in a small area in Colombia, we lose hundreds of dolphins to them."
Fernando Trujillo, marine biologist and Omacha Foundation co-founder
Toxins and climate threats
Trujillo's research, conducted in partnership with local fishermen, reveals alarming health crises among the dolphins. Blood samples show widespread contamination from microplastics and mercury-largely tied to illegal gold mining-while lung damage from rainforest fires, often set to clear land for agriculture, has been documented in Brazilian populations. The dolphins' sensitivity to environmental shifts makes them "sentinels of the rivers," Trujillo explained. "Their decline signals broader ecological collapse, from pollution to overfishing."
Climate change compounds these threats. A 2023 drought in Brazil killed over 130 pink river dolphins after shallow waters reached lethal temperatures exceeding 40°C (104°F). Such events underscore the urgency of conservation efforts, which now include community-led rescues during droughts and "pinger" devices-banana-shaped acoustic deterrents that reduce net damage by 40% in pilot programs along the Tapajós River.
Shifting perceptions
Efforts to reframe the dolphins' image are gaining traction. In Colombia, Romani Peña Gómez, a Tikuna Indigenous guide trained by the Omacha Foundation, now conducts health surveys and leads eco-tourism trips. "For us, the dolphins are the joy of the river," Gómez said, echoing a growing recognition of their ecological role. "Protecting them means protecting our own future."
"Before, we saw dolphins as enemies. Now, we work to coexist-so we all can eat."
Elias Correia da Silva, fisherman on the Tapajós River
A fragile symbol
Peschak's photographs arrive as global leaders convene in Belém for the UN Climate Change Conference (COP), casting the pink river dolphin as a "flagship species" for the Amazon's biodiversity crisis. "They represent the most diverse freshwater system on Earth," he said. "Their survival is tied to the health of the entire basin."
Conservationists like Mariana Paschoalini Frias of the World Wide Fund for Nature (WWF) emphasize that local involvement is key. By training fishermen to use pingers and rescue entangled dolphins, projects like the South American River Dolphin Initiative (SARDI) are fostering stewardship. "When communities lead," Frias said, "we build a sustainable Amazon-together."
