Have you ever dipped a net into the ocean and pulled up a couple of tiny, wriggling fish? You feel them twist in your hands before slipping back into the water and for a moment, you get a glimpse of the underwater world. Now stretch that image into something far bigger and darker: not a net a few feet wide, but nearly two miles long, suspended like a massive, invisible wall in the open ocean. Unlike a playful scoop from a pond, this wall doesn’t just catch a few small fish– it traps everything in its path. These gillnets are among the most widely used fishing methods worldwide, and their impact on marine life is devastating.
Every year, millions of marine animals are unintentionally caught and killed in gillnets. This phenomenon, known as bycatch, affects dolphins, sea turtles, seabirds, seals, sharks, rays, and countless other species never meant to be caught. Gillnets work by trapping fish by their gills as they try to swim through the mesh. Marine mammals that need to breathe air die by suffocation after prolonged struggles, while others sustain severe injuries from the netting. Sharks, rays, and other larger fish also become ensnared and restricted , which can lead to exhaustion, injury, or death. Globally, it is estimated that at least 300,000 whales, dolphins, and other cetaceans are killed as bycatch every year. In 2018 alone, up to 650,000 animals died from entanglement, and many survivors later perished from injuries.
Additionally, the damage from gillnets does not end once they are abandoned. These nets not only entangle marine life but also contribute to the broader crisis of ocean plastic pollution. Lost or discarded “ghost nets” continue to drift for years, killing marine life and disrupting ecosystems. Made from durable synthetic materials, they shed microplastics that are ingested by fish and shellfish, posing risks to animal and human health alike. Between 500,000 and one million tons of fishing nets enter the oceans annually, making up 46 percent of the Great Pacific Garbage Patch—spanning 1.6 million square kilometers or three times the size of France. Ghost nets also smother benthic habitats, destroy seagrasses and sediment-dwelling creatures, reduce biodiversity, and threaten fisheries that communities depend on for food and income. Even when nets settle on the seabed, they can be disturbed, refloat and repeat this cycle for 600–800 years.
Despite the massive scale of the problem, solutions exist. Some countries have begun to implement regulations to phase out or restrict gillnet use, especially in protected marine areas. Others are testing more selective fishing gear that reduces bycatch, such as hook-and-line systems or specially designed nets with escape hatches. Recovery and recycling programs for ghost gear are also growing, though they are often underfunded and lack international coordination.
Each step to limit gillnet use, recover ghost gear, or create safer fishing methods brings us closer to oceans where fish are abundant, ecosystems are healthy, and marine life can thrive. In this future, dipping a net into the water, like in that first glimpse of wriggling fish, can still inspire wonder and remind us of the vibrant life that the oceans hold.