![Turtle entangled in marine debris (ghost net)](https://upload.wikimedia.org/wikipedia/commons/5/50/Turtle_entangled_in_marine_debris_%28ghost_net%29.jpg)
Ghost nets are
fishing net
A fishing net is a net used for fishing. Nets are devices made from fibers woven in a grid-like structure. Some fishing nets are also called fish traps, for example fyke nets. Fishing nets are usually meshes formed by knotting a relatively thin ...
s that have been abandoned, lost or otherwise discarded in the ocean. These nets, often nearly invisible in the dim light, can be left tangled on a rocky reef or
drifting in the open sea. They can
entangle fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...
,
dolphin
A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the ...
s,
sea turtle
Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhead, ...
s,
shark
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimo ...
s,
dugong
The dugong (; ''Dugong dugon'') is a marine mammal. It is one of four living species of the order Sirenia, which also includes three species of manatees. It is the only living representative of the once-diverse family Dugongidae; its closest m ...
s,
crocodile
Crocodiles (family (biology), family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to inclu ...
s,
seabird
Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same enviro ...
s,
crab
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...
s, and other creatures, including the occasional human diver. Acting as designed, the nets restrict movement, causing starvation, laceration and infection, and suffocation in those that need to return to the surface to breathe.
It's estimated that around 48,000 tons of ghost nets are generated each year, and these may linger in the oceans for a considerable time before breaking-up.
Description
Some commercial fishermen use
gillnet
Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is ...
s. These are suspended in the sea by flotation
buoy
A buoy () is a floating device that can have many purposes. It can be anchored (stationary) or allowed to drift with ocean currents.
Types
Navigational buoys
* Race course marker buoys are used for buoy racing, the most prevalent form of yac ...
s, such as
glass float
Glass floats, glass fishing floats, or Japanese glass fishing floats are popular collectors' items. They were once used by fishermen in many parts of the world to keep their fishing nets, as well as longlines or droplines, afloat.
Large groups ...
s, along one edge. In this way they can form a vertical wall hundreds of metres long, where any fish within a certain size range can be caught. Normally these nets are collected by fishermen and the catch removed.
If this is not done, the net can continue to catch fish until the weight of the catch exceeds the buoyancy of the floats. The net then sinks, and the fish are devoured by bottom-dwelling crustaceans and other fish. Then the floats pull the net up again and the cycle continues. Given the high-quality synthetics that are used today, the destruction can continue for a long time.
The problem is not just nets but ghost gear in general;
[Hannah Gould]
Hidden problem of 'ghost gear': the abandoned fishing nets clogging up oceans
''Theguardian.com'', 10 September 2015 old-fashioned
crab trap
Crab traps are used to bait, lure, and catch crabs for commercial or recreational use. Crabbing or crab fishing is the recreational hobby and commercial occupation of fishing for crabs. Different types of traps are used depending on the type of ...
s, without the required "rot-out panel", also sit on the bottom, where they become self-baiting traps that can continue to trap marine life for years. Even balled-up
fishing line
A fishing line is a flexible, high-tensile cord used in angling to tether and pull in fish, in conjunction with at least one hook. Fishing lines are usually pulled by and stored in a reel, but can also be retrieved by hand, with a fixed attachm ...
can be deadly for a variety of creatures, including birds and marine mammals.
Over time the nets become more and more tangled. In general, fish are less likely to be trapped in gear that has been down a long time.
Fishermen sometimes abandon worn-out nets because it is often the easiest way to get rid of them.
[
The French government offered a reward for ghost nets handed in to local coastguards along sections of the Normandy coast between 1980 and 1981. The project was abandoned when people vandalized nets to claim rewards, without retrieving anything at all from the shoreline or ocean.
In September 2015, the Global Ghost Gear Initiative (GGGI) was created by the ]World Animal Protection
World Animal Protection, formerly The World Society for the Protection of Animals (WSPA) is an international non-profit animal rights organization that has been in operation since 1981. The charity describes its vision as: A world where animal ...
to give a unique and stronger voice to the cause.
The term ALDFG means "abandoned, lost and discarded fishing gear".
Environmental impact
From 2000 to 2012, the National Marine Fisheries Service
The National Marine Fisheries Service (NMFS), informally known as NOAA Fisheries, is a United States federal agency within the U.S. Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) that is responsible for the stew ...
reported an average of 11 large whales
Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and ...
entangled in ghost nets every year along the US west coast. From 2002 to 2010, 870 nets were recovered in Washington (state)
Washington (), officially the State of Washington, is a state in the Pacific Northwest region of the Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the Washington ...
with over 32,000 marine animals trapped inside. Ghost gear is estimated to account for 10% (640,000 tonnes) of all marine litter
Marine debris, also known as marine litter, is human-created waste that has deliberately or accidentally been released in a sea or ocean. Floating oceanic debris tends to accumulate at the center of gyres and on coastlines, frequently washing ...
.[
An estimated 46% of the Great Pacific garbage patch consists of fishing related plastics. Fishing nets account for about 1% of the total mass of all marine macroplastics larger than , and plastic fishing gear overall constitutes over two-thirds of the total mass.
According to the SeaDoc Society, each ghost net kills $20,000 worth of ]Dungeness crab
The Dungeness crab (''Metacarcinus magister'') is a species of crab inhabiting eelgrass beds and water bottoms along the west coast of North America. It typically grows to across the carapace and is a popular seafood. Its common name comes from ...
over 10 years. The Virginia Institute of Marine Science
The Virginia Institute of Marine Science (VIMS) is one of the largest marine research and education centers in the United States. Founded in 1940, VIMS is unique among marine science institutions in its legal mandate to provide research, educatio ...
calculated that ghost crab pots capture 1.25 million blue crab Blue crab may refer to:
* Blue Crab 11, an American sailboat design
* ''Callinectes sapidus'' – Chesapeake or Atlantic blue crab of the West Atlantic, introduced elsewhere
* ''Cardisoma guanhumi'' – blue land crab of the West Atlantic
* '' Disc ...
s each year in the Chesapeake Bay
The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic (United States), Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula (including the parts: the ...
alone.[
In May 2016, the ]Australian Fisheries Management Authority
The Australian Fisheries Management Authority (AFMA) is the Australian Government agency responsible for the management and sustainable use of fisheries resources including combating illegal fishing activities in the Australian Fishing Zone that c ...
(AFMA) recovered 10 tonnes of abandoned nets within the Australian Exclusive Economic Zone and Torres Strait
The Torres Strait (), also known as Zenadh Kes, is a strait between Australia and the Melanesian island of New Guinea. It is wide at its narrowest extent. To the south is Cape York Peninsula, the northernmost extremity of the Australian mai ...
protected zone perimeters. One protected turtle was rescued.
The northern Australian olive ridley sea turtle Lepidochelys olivacea
The olive ridley sea turtle (''Lepidochelys olivacea''), also known Common name, commonly as the Pacific ridley sea turtle, is a species of turtle in the Family (biology), family Cheloniidae. The species is the second-smallest and most abundant ...
, is a genetically distinct variation of the olive ridley sea turtle. Ghost nets pose a threat to the continued existence of the northern Australian variety. Without further action to preserve the northern Australian olive ridley sea turtle, the population could face extinction.
Researches in Brazil used social media to estimate how ghost nets have negatively affected the Brazilian marine biota. Footage of ghost nets found on Google and YouTube were obtained and analyzed to arrive at the results of the study. They found that ghost nets have an adverse effect on several marine species, including large marine animals, such as the Bryde's whale and Guiana dolphin.
Solutions
Alternative materials and practice
Unlike synthetic fishing nets, biodegradable
Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegradati ...
fishing nets decompose naturally under water after a certain period of time. Coconut fibre (coir
Coir (), also called coconut fibre, is a natural fibre extracted from the outer husk of coconut and used in products such as floor mats, doormats, brushes, and mattresses. Coir is the fibrous material found between the hard, internal shell ...
) fishing nets are commercially made and are hence a practical solution that can be taken by fishermen.
Technology systems for marking and tracking fishing gear, including GPS tracking, are being trialled to promote greater accountability and transparency.
Collection and recycling
Legalizing gear retrievals and establishing waste management systems is required to manage and mitigate abandoned, lost and discarded fishing gear at-sea. The company Net-works worked out a solution to turn discarded fishing nets into carpet tiles.
Between 2008 and 2015, the US Fishing for Energy initiative collected 2.8 million pounds of fishing gear, and in partnership with Covanta Energy
Covanta Holding Corporation is a private energy-from-waste and industrial waste management services company headquartered in Morristown, New Jersey. Most of its revenue comes from operating power plants that burn trash as fuel. Covanta charges a ...
turned this into enough electricity to power 182 homes for one year by incineration.[
One retrieval initiative in Southwest Nova Scotia in Canada conducted 60 retrieval trips, searched ~1523 km2 of the seafloor and removed 7064 kg of abandoned, lost, and discarded fishing gear (ALDFG) (comprising 66% lobster traps and 22% dragger cable). Lost traps continued to capture target and non-target species. A total of 15 different species were released from retrieved ALDFG, including 239 lobsters (67% were market-sized) and seven groundfish (including five species-at-risk). The commercial losses from ALDFG in Southwest Nova Scotia were estimated at $175,000 CAD annually.
In 2009 world-renowned Dutch technical diver Pascal van Erp started to recover abandoned ghost fishing gear entangled on North Sea wrecks. He soon inspired others. Organised teams of volunteer technical divers recovered tons of ghost fishing gear off the Netherlands coastline. The loop was then closed - after a season's diving 22 tons of fishing gear was sent to the Aquafil Group for recycling back into new Nylon 6 material. In 2012 Pascal van Erp formally founded the not-for-profit Ghost Fishing organisation. In 2020 the Ghost Fishing Foundation rebranded as the Ghost Diving Foundation.
A plan to protect UK seas from ghost fishing was backed by the ]European Parliament
The European Parliament (EP) is one of the legislative bodies of the European Union and one of its seven institutions. Together with the Council of the European Union (known as the Council and informally as the Council of Ministers), it adopts ...
Fisheries Committee in 2018. Mr. Flack, who led the committee, said: "Abandoned fishing nets are polluting our seas, wasting fishing stocks and indiscriminately killing whales, sea lions or even dolphins. The tragedy of ghost fishing must end".
Net amnesty schemes such as Fishing for Litter create incentives for the collection and responsible disposal of end of life fishing gear. These schemes address the root cause for many net abandonments, which is the financial cost of their disposal.
Fishing nets are often made from extremely high quality plastics to ensure suitable strength, which makes them desirable for recycling. Initiatives like Healthy Seas are connecting environmental cleanup projects to manufacturers to re-use these materials. Recycled waste nets can be made into yarn and consumer products, such as swimwear.
In Australia, the Carpentaria Ghost Nets Program has collaborated with indigenous communities to increase awareness of ghost nets and to foster long term solutions. The program has trained indigenous northern Australians in scouting for ghost nets and in removing ghost nets and other plastic pollution.
See also
*Drift netting
Drift netting is a fishing technique where nets, called drift nets, hang vertically in the water column without being anchored to the bottom. The nets are kept vertical in the water by floats attached to a rope along the top of the net and weig ...
* Monofilament fishing line#Environmental impact
*The Derelict Crab Trap Program The Derelict Crab Trap Removal Program was created by the Louisiana Wildlife and Fisheries Commission in 2004. This was created to remove derelict crab traps from state-owned lakes and river-beds and to reduce the potential impact from these traps. ...
*Plastic pollution
Plastic pollution is the accumulation of plastic objects and particles (e.g. plastic bottles, bags and microbeads) in the Earth's environment that adversely affects humans, wildlife and their habitat. Plastics that act as pollutants are catego ...
General:
*Marine debris
Marine debris, also known as marine litter, is human-created waste that has deliberately or accidentally been released in a sea or ocean. Floating oceanic debris tends to accumulate at the center of gyres and on coastlines, frequently washing ...
*List of environmental issues
This is an alphabetical list of environmental issues, harmful aspects of human activity on the biophysical environment. They are loosely divided into causes, effects and mitigation, noting that effects are interconnected and can cause new effects. ...
Notes
References
*Macfadyen G, Huntington T and Cappell R (2009) tp://ftp.fao.org/docrep/fao/011/i0620e/i0620e.pdf Abandoned, lost or otherwise discarded fishing gearFAO
The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...
: Fisheries and Aquaculture, ''Technical paper 523''. Rome.
External links
Film on Ghost nets in the Indian Ocean
Ghost nets in the Indian Ocean
Ghost Diving - International cleanup projects
Ghost Net Project
Carpentaria Ghost Net Programme
Team Hunts Deadly 'Ghost Nets' in the Pacific
Ghost nets hurting marine environment: UN report
{{Fisheries and fishing
Environmental impact of fishing
Nets (devices)
Water pollution