A ghost net is a fishing net that has been abandoned, lost, or deliberately discarded in the ocean, where it continues to trap and kill marine life for years or even centuries. These nets are made from synthetic plastics that don’t break down naturally, so they drift through currents or settle on the seafloor, silently “fishing” long after anyone is using them. Ghost nets are one of the most destructive forms of ocean pollution, and they make up at least 46% of the total plastic mass in the Great Pacific Garbage Patch.
What Ghost Nets Are Made Of
Modern fishing nets are manufactured from synthetic polymers, primarily polyamide (nylon), polyethylene, and polypropylene. These materials replaced older nets made from natural fibers like hemp, cotton, and coconut, which degraded quickly in saltwater. The switch to synthetics dramatically increased fishing efficiency because the nets last longer and hold up in rough conditions. That same durability is exactly what makes them so dangerous once they end up in the ocean: they’re non-biodegradable, resistant to saltwater, and can persist for centuries.
Nets end up as ghost gear for a variety of reasons. Storms rip them free from boats. They snag on rocky seabeds or coral and are cut loose. Some are dumped illegally because disposal on land costs money. Regardless of how they get there, the result is the same: a nearly invisible web of synthetic plastic drifting through marine ecosystems.
How Many Enter the Ocean Each Year
For decades, the commonly cited figure was 640,000 metric tons of fishing gear lost to the ocean annually. Researchers have since noted that this estimate is outdated and poorly sourced, but it persists in policy discussions. The true number remains difficult to pin down because losses happen across millions of vessels worldwide, many of them small-scale operations with no reporting requirements. What’s clear is that the volume is enormous. A 2022 study published in Science Advances found that gear loss is widespread across all fishing sectors and ocean regions, reinforcing that this is a systemic problem rather than a localized one.
The Toll on Marine Life
Ghost nets kill hundreds of thousands of marine mammals and sea turtles every year. Whales, dolphins, seals, sea lions, and turtles all become entangled as they swim through or near drifting nets. For smaller animals like sea turtles, porpoises, and small whales, a heavy net can cause immediate drowning. Larger animals often survive the initial entanglement but suffer drawn-out injuries: the netting cuts into their skin, restricts movement, prevents feeding, and leads to infection or slow starvation.
Entanglement is considered a primary cause of human-caused death in several whale species, particularly right whales, humpback whales, and gray whales. Right whales are critically endangered, with only a few hundred remaining in the North Atlantic, so every entanglement death pushes the species closer to collapse. Even leatherback sea turtles, which can measure over six feet long and weigh a ton, regularly need to be disentangled from ghost gear by rescue teams.
Fish are also caught in ghost nets in large numbers. The nets don’t stop working just because no one is hauling them in. Dead fish attract scavengers, which then become trapped themselves, creating a cycle of killing that can continue indefinitely as long as the net holds together.
Damage to Coral Reefs
Ghost nets don’t just float at the surface. Many sink and drape across coral reefs, where they cause serious physical damage. The nets break coral branches, block sunlight that corals need for photosynthesis, and scrape against living tissue as currents push the netting back and forth. Over time, this abrasion kills the coral underneath.
NOAA divers working in atoll lagoons have documented significant coral loss at sites where ghost nets accumulated. After removing nets from shallow reefs, they found that areas with prolonged net contact had significantly less live coral and more bare, dead substrate compared to nearby net-free zones. Coral reefs support roughly a quarter of all marine species, so damage to reef systems has cascading effects throughout ocean food webs.
Microplastic Pollution From Degrading Nets
Even as ghost nets slowly break apart, they don’t disappear. They fragment into smaller and smaller pieces, eventually becoming microplastics (particles smaller than 5 millimeters) and nanoplastics. This degradation process can take centuries, and throughout that time, the nets release both plastic particles and toxic chemical compounds into surrounding water and sediment.
Research along Spain’s Mediterranean coast has directly measured this effect. In areas where abandoned fishing nets were present, the concentration of line-shaped microplastic particles in seafloor sediments jumped dramatically. In one location near Alicante, these particles increased eightfold compared to control sites without nets. In Benidorm, net-impacted sediments showed a similar spike. The particles matched the same polymer types used in modern net manufacturing, confirming that the nets were actively shedding plastic into the environment. These microplastics enter the food chain when small organisms ingest them, eventually working their way up to fish, seabirds, and marine mammals.
Cleanup and Recovery Efforts
Removing ghost nets from the ocean is labor-intensive and expensive. Nets tangled on coral reefs require trained divers who must carefully cut the gear away without causing further damage to the reef. Derelict crab traps and other gear on the seafloor are located using sonar and visual surveys, then hauled up by vessel. In many cases, the sheer volume of gear and the vastness of the ocean make recovery logistically challenging.
Several organizations coordinate large-scale removal operations. NOAA runs programs focused on locating and retrieving derelict fishing gear in U.S. waters. The Global Ghost Gear Initiative, a partnership recognized by the United Nations, has set a goal of getting at least a quarter of the global commercial seafood and fisheries sector to adopt best practices for gear management, from production through end-of-life recycling, by 2025. These best practices include marking gear so lost nets can be traced back to their source, improving net design to reduce the chance of loss, and creating incentives for fishers to report and retrieve lost equipment rather than leaving it behind.
Turning Ghost Nets Into Products
Because fishing nets are made from recyclable plastics, recovered ghost nets can be processed into new materials. One company, Bureo, collects discarded fishing nets from coastal communities and converts them into a recycled nylon material called NetPlus. This material has been used in a range of consumer products, from performance outdoor clothing to hat brims. Patagonia, for example, uses NetPlus material in some of its products. Peak Performance has developed a jacket concept using the recycled nylon alongside other traceable materials.
These recycling programs serve a dual purpose. They reduce the volume of ghost gear in the ocean, and they provide economic incentives for fishing communities to collect and turn in old nets instead of dumping them. Programs like Fishing for Energy also provide grant funding for projects that develop innovative ways to reduce gear loss at sea and build sustainable local systems for managing end-of-life fishing equipment. The economics still favor prevention over cleanup, though. Keeping nets out of the ocean in the first place is far cheaper and more effective than retrieving them after they’ve already caused damage.