Ghost Nets and Their Effects at Sea
A ghost net is a fishing net lost or abandoned at sea that keeps catching marine life.
A ghost net is a fishing net lost or abandoned at sea that keeps catching fish, turtles, seabirds and other animals with nobody using it. The technical term is ALDFG, for abandoned, lost or otherwise discarded fishing gear.[1] The problem took its modern size after net materials changed. A 2022 study based on interviews with fishers estimated that about 2% of the world's fishing gear ends up in the sea each year.[4] Türkiye's agriculture ministry has been removing these nets since 2014, and between 2021 and 2024 it took 1.1 million square metres of them out of the Sea of Marmara alone.[9]
From Natural Fibre to Synthetics
Until the 1950s most nets and ropes were made of natural fibre, which rotted quickly in seawater. A lost net fell apart before long. The same weakness cost fishers money, since worn gear had to be replaced often, and the industry moved to synthetic materials that last far longer.[2] What saved money on the boat created a new problem in the water, because a synthetic net that goes missing can keep working for years.[1]
It works in a simple cycle. A gillnet that nobody recovers stays upright on its floats and goes on catching fish. When the weight of the catch beats the floats, it sinks to the bottom, where crustaceans and other fish eat what it holds. Then the floats lift it up and the cycle starts again.[1] Traps behave in a similar way. Older crab pots without a rot-out panel, the section that decays to let animals escape, can go on trapping marine life on the bottom for years.[1]
How the Problem Came to Light
Fisheries scientists began to recognise ghost fishing in the mid 1970s. The definition dates from the same period: the ability of fishing gear to go on fishing after the fisher has lost all control of it.[13] Early records showed that fish were not the only victims. In 1975 a reindeer on an Alaskan island was photographed tangled in 65 pounds of net. A single net found in the North Pacific held 99 dead seabirds, two dead sharks and more than 200 fish.[2]
By the late 1980s the subject had reached international policy. The possibility of ghost fishing was among the reasons given for closing the high-seas driftnet fishery, and the FAO Code of Conduct for Responsible Fisheries of 1995 called for gear losses to be prevented. Researchers at the time still complained that few studies had actually measured the deaths involved.[13]
How Much Gear Is Lost
The lack of measurement shows in the most quoted figure of all. The 640,000 tonnes a year attributed to a 2009 FAO and UNEP report was derived from an assumption that fishing gear makes up 10% of all marine litter. It was repeated for years, and researchers who later looked into it found it unsubstantiated.[4]
Firmer numbers came from Kelsey Richardson and colleagues at CSIRO in Australia and the University of Tasmania. In 2019 they reviewed 68 publications from 1975 to 2017 and estimated annual losses of 5.7% of nets, 8.6% of traps and 29% of lines. The individual studies ranged from zero to 88%.[3] Because of that spread, the group changed method in 2022 and asked about 450 fishers in the United States, Morocco, Indonesia, Belize, Peru, Iceland and New Zealand how much gear they lose each year. The average came to 1.82%. Scaled up by global fishing effort, that means roughly 2,963 square kilometres of gillnet, 75,049 square kilometres of purse seine, more than 25 million pots and traps and about 14 billion longline hooks a year.[4] The two studies use different methods and their results differ with them, the 2022 figures being lower.
Counts of what the gear catches come from individual regions. In Washington State, 870 nets recovered between 2002 and 2010 held more than 32,000 marine animals. The Virginia Institute of Marine Science estimates that ghost pots in Chesapeake Bay catch 1.25 million blue crabs a year. One net found at Pearl and Hermes Atoll in Hawaii in 2014 weighed 11.5 tons.[1]
Attempts to Collect the Nets
One of the first government schemes on record was French. In 1980 and 1981 a reward was offered for ghost nets handed in along the Normandy coast, and it was abandoned when people began cutting up sound nets to claim the money.[1] Fishing for Energy, started in the United States in 2008, tackled the fisher's disposal problem instead. By 2015 it had collected 2.8 million pounds of gear, which was burned to generate enough electricity for 182 homes for a year.[1]
In Europe the work began with divers. Pascal van Erp, a Dutch technical diver who dived on wrecks, started recovering nets snagged on North Sea wrecks in 2009, and others joined him. One season's 22 tons went to the Italian company Aquafil to be recycled into Nylon 6. He founded the not-for-profit Ghost Fishing in 2012, and it became Ghost Diving in 2020.[1] Healthy Seas, with Aquafil among its founders, started in 2013 and reports having collected 1,309 tons of nets and other marine litter since then.[8] In September 2015 World Animal Protection set up the Global Ghost Gear Initiative to bring this work together.[1]
International Rules
The basic rule for gear at sea is MARPOL Annex V, in force since 31 December 1988. Amendments effective on 1 January 2013 turned it into a general ban on discharging garbage at sea, with accidental loss among the exceptions.[6] That leaves the question of how to tell whose net has been lost. In June 2022 the IMO's Marine Environment Protection Committee decided to develop a mandatory requirement for marking gear, and a group of EU and other states submitted draft Annex V amendments for the sub-committee meeting of February 2026.[5] No such amendment is in force yet. The EU has taken another route: its single-use plastics directive (2019/904) puts plastic fishing gear under producer responsibility and moves the cost of collecting waste gear onto manufacturers.[7]
Türkiye and the Sea of Marmara
Türkiye's clean-up project began in 2014. In the Marmara it speeded up after the mucilage crisis of 2021. When Environment Minister Murat Kurum announced the Marmara Sea Protection Action Plan on 6 June 2021, it included a target of clearing ghost nets within a year.[10] According to the agriculture ministry's statement of February 2025, 1.1 million square metres were removed from the Marmara between 2021 and 2024, so the work took longer than the plan had said.
The same statement gave separate figures for 2024 and for the project as a whole. Minister İbrahim Yumaklı said that in 2024 the ministry had surveyed 146.1 million square metres of seas and inland waters and removed 1.6 million square metres of net, which he compared to 224 football pitches, along with 13,750 other pieces of gear. The total since 2014 stood at 452.6 million square metres surveyed, 2.6 million square metres of net and 65,000 pieces of gear.[9] A report from February 2026 quoting fisheries director general Turgay Türkyılmaz gives 805 million square metres surveyed and 2.9 million square metres of net.[12] The two totals belong to different dates, and the later one is known only from that report.
Volunteers now play a part too. After a tip-off through Mavi Atlas, a mobile app run by the Marine Life Conservation Association and the ministry, divers in an operation announced in June 2026 made seven dives at six points off Marmara Island over four days. They brought up about 15,000 square metres of net, 225 kilos of lead and lengths of rope, and released the animals still alive in the mesh.[11] These same waters carry heavy commercial shipping traffic.
Frequently asked questions
What is a ghost net?
A ghost net is a fishing net lost or abandoned at sea that keeps catching marine life.
Why do ghost nets keep fishing for years?
Synthetic nets do not rot in the sea. The net sinks under the weight of its catch, rises again once the catch has been eaten, and goes on fishing.
How many ghost nets has Türkiye removed?
The ministry reported 2.6 million square metres removed from 2014 to early 2025, of which 1.1 million came from the Marmara between 2021 and 2024. A February 2026 report gives a total of 2.9 million square metres.
Sources
- Wikipedia. Ghost net (secondary source).
- Juliet Lamb. Ghost Fishing, JSTOR Daily, 2016, updated 2018.
- Richardson K., Hardesty B. D., Wilcox C. Estimates of Fishing Gear Loss Rates at a Global Scale, Fish and Fisheries, 2019.
- Richardson K. et al. Global Estimates of Fishing Gear Lost to the Ocean Each Year, Science Advances, 2022; CSIRO, October 2022; Hakai Magazine. In Graphic Detail: Gluts of Ghost Gear; Olive Ridley Project. How Much Ghost Gear Is in the Ocean.
- Ocean Conservancy. IMO Gear Marking Statement, 13 June 2022; Council of the EU. WK 15812/2025, draft amendment proposal for PPR 13.
- IMO. Prevention of Pollution by Garbage from Ships (MARPOL Annex V).
- European Union. Directive 2019/904.
- Healthy Seas. Press Kit.
- Republic of Türkiye Ministry of Agriculture and Forestry. Statement on ghost nets recovered in 2024, 17 February 2025.
- Diken. Report on the Marmara Protection Action Plan, 6 June 2021.
- Ekonomist. Mavi Atlas İlk Meyvesini Verdi, 2 June 2026.
- Vatan. 11 Yılda 2,9 Milyon Metrekarelik Sessiz Katil Denizden Çıkarıldı, 18 February 2026.
- Matsuoka T., Nakashima T., Nagasawa N. Review of Ghost-Fishing: Scientific Approaches to Evaluation and Solution, Kagoshima University.
