- Studies and NGOs have documented lost or abandoned gear from open-net aquaculture operations in coastal areas across cold and temperate latitudes, where fish farming in the sea expanded rapidly in the 1980s and ’90s.
- In Chile, Greece and Canada, for example, observers have reported finding disused buoys, sections of rusting platforms, expanded polystyrene, net cages and other debris washed up on shorelines, or sunk in the water.
- Guidelines published by the Global Ghost Gear Initiative (GGGI), a worldwide alliance of groups seeking solutions to fishing gear pollution, say neglected or mismanaged aquaculture gear can disperse in the environment and break down into debris of various sizes, posing risks such as entrapping marine life, damaging habitats or contributing to microplastic pollution.
- Some industry groups say current regulations and practices suffice to prevent ongoing pollution and they are working to resolve legacy contamination.
Each year since 2021, Pia Reveco and her husband have set sail from Puerto Montt to spend the Chilean summers navigating Patagonia aboard their sailboat. Last year, they traveled along the fjords and mountains of the Golfo de Penas; three years ago, they reached Laguna San Rafael National Park, where a glacier resembling an ice tongue meets the sea. This summer, they opted instead for a shorter trip to the Guaitecas archipelago, a group of sparse islands in the Aysén region known for its rich biodiversity.
During these journeys, they report frequently coming across fish farms, mostly salmoneras, Spanish for salmon farms. On their most recent expedition, which ran from December to March, Reveco posted on X about at least 23 sites that appeared to her abandoned or in bad condition, with corroded, broken or sinking infrastructure and teeming with birds, she told Mongabay.
A 2021 study published in the science journal Marine Pollution Bulletin identified mussel and salmon aquaculture as primary sources of floating marine debris in northern Chilean Patagonia, especially buoys and other plastic floating devices.
Daniel Caniullán, a fishing vessel owner, shellfish gatherer and Indigenous community leader involved in campaigns against the salmon industry, has often documented buoys, sections of rusting platforms and plastic pipes washing ashore on the pristine beaches of the Guaitecas, where he lives.
“We, the Indigenous seafaring fishers of this territory, have seen this type of salmon farming pollution in the area for more than 40 years,” Caniullán texted Mongabay.
In such remote areas, he added, government oversight is minimal. “It’s like having a guard dog with no teeth.”
For its part, Chile’s National Fisheries and Aquaculture Service (SERNAPESCA) told Mongabay in an emailed statement that it regularly conducts sanitary, environmental and production inspections of fish farms, following a national protocol, as well as a special inspection plan for those farms located in protected areas of the Aysén and Magallanes regions.
If waste is detected, the statement said, current regulations require farm operators to remove the structures, debris or other materials identified during beach and area inspections within 10 days. “A deadline that is met by the companies 95% of the time,” the statement added.
Mongabay reached out to two groups representing the Chilean salmon industry for their perspective for this story. SalmonChile did not respond. The Chilean Salmon Council, via public relations specialist Jim McCarthy, did not comment specifically on the issues raised.
Aquaculture equipment management issues aren’t limited to Patagonia. Studies and NGOs have documented lost or abandoned gear from open-net aquaculture operations in other coastal areas across cold and temperate latitudes, where mariculture — fish farming in the sea — expanded rapidly in the 1980s and ’90s. Some of these studies are cited in the Best Practice Framework for the Management of Aquaculture Gear, published in 2021 by the Global Ghost Gear Initiative (GGGI), a worldwide alliance of groups ranging from seafood retailers and fishing companies to governments and nongovernmental organizations that seeks solutions to fishing gear pollution. The report says that when aquaculture gear is neglected or mismanaged, equipment like fish cages, rafts, boats, tanks, piping, buoys, nets, moorings and ropes can disperse in the environment and break down into debris of various sizes, posing risks such as entrapping marine life, damaging habitats or contributing to microplastic pollution.
“People ask us how much [fishing] gear is lost every year. The answer to that is one that nobody really knows,” said Joel Baziuk, associate director of GGGI, which is a project of the Washington, D.C.-based NGO the Ocean Conservancy. “But what we can say is that wherever we look for it — where there’s fishing going on — we find it. And I would imagine it would be a very similar situation when it comes to decommissioned aquaculture farms. If you look for them, it will be there,” he told Mongabay.
In western Greece, the Dutch foundation Healthy Seas has launched a series of cleanups targeting “ghost” fish farms, as it calls aquaculture sites left to decay in the sea after they’re abandoned by their owners or no longer in use. During such efforts in 2021, divers from partner organization Ghost Diving, also headquartered in the Netherlands, found meadows of Posidonia oceanica, a vital seagrass species native to the Mediterranean, smothered beneath sunken net cages, Pascal van Erp, co-founder of Ghost Diving and deputy director of Healthy Seas, told Mongabay.
“We have found the occasional animal being trapped,” Anastasios Filippides, co-founder and executive director of the Greek NGO Ozon, who took part in some of the cleanups, told Mongabay in an interview. But the abandonment of equipment on the seabed appears particularly devastating to the habitat, he said.
Since 2021, Filippides has been mapping and monitoring fish farms in the Saronic Gulf, part of the Aegean Sea. He said he began after noticing large amounts of expanded polystyrene washing up on local beaches. Tracing the origin of this familiar soft, white polymer material initially led him to the buoys and floating platforms of 36 operating and five inactive fish farms in the area. According to a presentation he gave at the Hellenic Parliament in Athens in 2023, less than 40% of the active sites were in excellent or good condition; the rest were leaking polystyrene into the environment.
Following the release of the report underlying Filippides’s presentation, Ozon was approached by Healthy Seas, which at that time was addressing a large ghost fish farm off the Greek island of Ithaca, to survey other areas in western Greece. To date, Ozon has identified 20 abandoned fish farms with obvious debris throughout the Saronic, Corinthian and Amvrakikos gulfs, as well as along the country’s western coastline, Filippides said, and another 18 without obvious debris that remain to be searched for old equipment lying on the seabed.
The notion of “abandonment” is often contested in Greece, Filippides noted via email, as in some cases licenses may not yet have been revoked or are tied up in legal proceedings. He said most are remnants of the woes that followed the 2009 financial crisis, which forced the aquaculture companies that owned them out of business. A few others were simply left behind when companies relocated, he said.
Ismini Bogdanou, director of communications and public relations of the Hellenic Aquaculture Producers Organization (HAPO), which includes 22 companies farming primarily sea bass and sea bream in Greece, acknowledged the issue in an email to Mongabay. “HAPO has in numerous cases discussed with the Ministry of Rural Development methods to end the ghost farm reality which is negatively impacting the environment and the overall image of the industry. Private intervention to collect leftover equipment in the sea and on shore is a complex and complicated process, not a simple procedure at all, and requests the cooperation of (mostly unwilling) owners (that abandoned the farms due to financial reasons), local authorities, jurisdiction, and ministries,” Bogdanou wrote. He added that ownership in Greece is “highly guarded.”
“HAPO members own healthy and fully operational farms” that “abide to best aquaculture practices, that respect animal welfare and protect the sea and land in areas of operation,” Bogdanou said.
“We’re trying to develop the tools with the industries … to prevent this as much as possible,” said Baziuk of GGGI. “But the legacy stuff still needs to be dealt with.”
Beyond encouraging aquaculture producer associations to develop codes to reduce aquatic debris, the GGGI’s best practice framework advises governments and regulating authorities to ensure a plan is in place that clearly outlines procedures for installing, operating and decommissioning aquaculture installations as part of their licensing processes.
“Seafood farmers in Canada are committed to keeping the areas where they farm beautiful and clean,” the Canadian Aquaculture Industry Alliance (CAIA) told Mongabay in an emailed statement. “In addition to strict regulatory requirements, all the salmon farming companies have internal policies in place regarding marine debris and engage in regular beach cleans within their tenure boundary and a wider-area beach cleanup of the adjacent bays, channels, and waterways.”
Yet, on the country’s east coast, the Atlantic Salmon Federation (ASF), a Canadian NGO, said it has found remote coves strewn with abandoned sea cages, nets, ropes, buoys and feed bags — some left unattended since as far back as 2011, when high-resolution satellite images became available. ASF’s latest survey, released in June and based on imagery from the European Space Agency, identified six sites off Newfoundland and Labrador showing the presence of damaged or obsolete equipment.
CAIA’s local counterpart, the Newfoundland Aquaculture Industry Association (NAIA), posted two statements on its website following ASF’s most recent findings: one accuses the NGO of “disinformation tactics” and another affirms that Newfoundland and Labrador fish farmers are “committed to responsible marine equipment storage, disposal and recycling.” According to industry website Aquaculture North America, additional NAIA statement said “Actions have been undertaken by salmon farming companies to clean up legacy equipment from past practices and/or previous owners” and that such cleanup activity began “over five years ago and is close to being completed.”
Government agencies have ordered companies to clean up abandoned gear following ASF’s earlier reports. But according to Neville Crabbe, ASF’s communications vice president, no fines or penalties have been issued. The CAIA statement to Mongabay also specified that in British Columbia, on the west coast, companies are legally required to remediate sites and pay into a collective environmental bond managed by the BC Salmon Farmers Association. Back east, in Newfoundland and Labrador, each company is required to provide a bond or surety as protection against bankruptcy or site abandonment.
As the federal government has announced a ban on open net-pen salmon aquaculture in British Columbia by 2029, wild salmon conservation organizations like ASF fear a potential expansion of sea-cage operations along the shores of Newfoundland and Labrador and are asking for a moratorium.
Salmon farming can provide jobs, contribute to local economies and provide a protein-rich source of food. But the industry also faces challenges and criticism, typically regarding nutrient pollution, antibiotic use, sea lice management and escaped fish. However, marine debris is probably the most visible impact, Crabbe said.
In Chile, the world’s second-largest farmed salmon exporter, after Norway, 1,331 concessions were granted to more than 50 companies. Many of the farms are located in remote southern regions like Los Lagos, Aysén and Magallanes, which are dotted by fjords and home to many national parks and marine protected areas. Since 2017, Greenpeace Chile has led three expeditions to monitor conditions in these areas, as part of an active campaign against salmoneras in the region.
Following the most recent expedition, in 2023, Greenpeace Chile staff told Mongabay the group filed complaints with SERNAPESCA, Chile’s Superintendence of the Environment (SMA), and local port captaincies under Chile’s Maritime Authority (DIRECTEMAR) for six aquaculture sites in the region of Magallanes. Beyond derelict buoys, ropes and cages, in one case the group also alleges it found a floating warehouse containing hazardous chemicals. In addition to the environmental concerns, Estefanía González, Greenpeace Chile’s deputy campaign director at the time, who led the expedition, emphasized maritime safety. Local mariners, often Indigenous people, navigating in these areas risk encountering barely visible, sometimes submerged infrastructure, she told Mongabay.
Inspections followed Greenpeace Chile’s complaints. “Authorities confirmed the presence of marine debris, unused infrastructure, and abandoned buoys and ropes” at three of the sites, spokesperson Silvana Espinosa and campaign specialist Roxana Núñez with Greenpeace Chile told Mongabay in an emailed follow-up document. But the organization says it did not receive any other official communications confirming whether the sites have been cleaned or remediated, or whether the other three sites it complained about were ever inspected. “[T]he lack of transparency from the authorities regarding the progress and outcomes of the inspections is concerning,” the follow-up document states.
Rafael González Hernández, first lieutenant of the Port Captaincy of Puerto Natales, confirmed that his unit carried out joint inspections with SERNAPESCA following Greenpeace Chile’s complaints, but he did not respond to Mongabay’s questions about which sites were inspected, the findings, or any cleanup or regulatory action that may have resulted. SERNAPESCA did not respond to Mongabay’s queries about the status of these complaints.
However, SERNAPESCA has publicized its response to other recent incidents involving debris from aquaculture operations. For example, in an August 2024 press release, the agency said it had confirmed the presence of aquaculture debris at five out of six sites in Aysén it had inspected in response to an original list of 11 complaints filed by the Chilean NGO Committee for the Defense of Fauna and Flora. And in April 2025, the agency announced it had found “an accumulation of waste from aquaculture activities,” including structural elements, buoys, pipes, and expanded polystyrene, along a stretch of coastline in Aysén’s Magdalena Island National Park. It said it contacted industry groups, which completed a cleanup.
“The situation was worrying due to the magnitude of the contamination, which extended along approximately 10 kilometers [6 miles], and the fact that it affects a National Park, a protected area of high ecological value,” Daniela Leiva, SERNAPESCA’s regional director for Aysén, said in the announcement. “It is essential to raise standards for material and waste management in the aquaculture sector and strengthen coordination between companies to clean up these areas.”
“I’m just a concerned citizen and I love the sea,” Reveco, the sailor, told Mongabay, describing her motives for posting about the apparently derelict aquaculture operations she encounters. “We have a boat. So, we travel by because we can. But a normal Chilean person who lives in the city doesn’t have any idea of what is going on in the south of our country.”
Banner image: Sunken salmon farming equipment photographed at a site known as The Locker near Gaultois, Newfoundland and Labrador, Canada, on June 23, 2025. The Atlantic Salmon Foundation, the Canadian NGO that documented the site, states on its website that aquaculture debris at The Locker had been cleaned up following a complaint it made to authorities in 2024, but the cleanup did not include sunken debris and “significant amounts of salmon farm equipment in very poor condition have been hauled back into the area” since it occurred. Image courtesy of Jake Dicks/ASF.
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Citation:
Ahrendt, C., DeCoite, M., Pulgar, J., Pozo, K., Galbán-Malagón, C., & Hinojosa, I. A. (2021). A decade later, reviewing floating marine debris in northern Chilean Patagonia. Marine Pollution Bulletin, 168, 112372. doi:10.1016/j.marpolbul.2021.112372
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