Ghost nets are fishing nets that have been abandoned, lost, or otherwise discarded in the ocean, lakes, and rivers. [1] 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, dolphins, sea turtles, sharks, dugongs, crocodiles, seabirds, crabs, and other creatures, including the occasional human diver. [2] 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. [3] It's estimated that around 48 million tons (48,000 kt) of lost fishing gear is generated each year, not including those that were abandoned or discarded [4] and these may linger in the oceans for a considerable time before breaking-up.
Some commercial fishermen use gillnets. These are suspended in the sea by flotation buoys, such as glass floats, 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; [5] old-fashioned crab traps, 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 can be deadly for a variety of creatures, including birds and marine mammals. [6] 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. [7]
Fishermen sometimes abandon worn-out nets because it is often the easiest way to get rid of them. [5]
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. [8]
In September 2015, the Global Ghost Gear Initiative (GGGI) was created by the World Animal Protection to give a unique and stronger voice to the cause.
The term ALDFG means "abandoned, lost and discarded fishing gear". [6]
From 2000 to 2012, the National Marine Fisheries Service reported an average of 11 large whales entangled in ghost nets every year along the US west coast. From 2002 to 2010, 870 nets were recovered in Washington (state) with over 32,000 marine animals trapped inside. Ghost gear is estimated to account for 10% (640,000 tonnes) of all marine litter. [5]
An estimated 46% of the Great Pacific Garbage Patch consists of fishing related plastics. [9] Fishing nets account for about 1% of the total mass of all marine macroplastics larger than 200 millimetres (7.9 in), and plastic fishing gear overall constitutes over two-thirds of the total mass. [10]
According to the SeaDoc Society, each ghost net kills $20,000 worth of Dungeness crab over 10 years. The Virginia Institute of Marine Science calculated that ghost crab pots capture 1.25 million blue crabs each year in the Chesapeake Bay alone. [5]
In May 2016, the Australian Fisheries Management Authority (AFMA) recovered 10 tonnes of abandoned nets within the Australian Exclusive Economic Zone and Torres Strait protected zone perimeters. One protected turtle was rescued. [11]
The northern Australian olive ridley sea turtle Lepidochelys olivacea, 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. [12]
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. [13]
Unlike synthetic fishing nets, biodegradable fishing nets decompose naturally under water after a certain period of time. Coconut fibre (coir) fishing nets are commercially made and are hence a practical solution that can be taken by fishermen. [14] [15]
Technology systems for marking and tracking fishing gear, including GPS tracking, are being trialled to promote greater accountability and transparency. [16]
Legalizing gear retrievals and establishing waste management systems is required to manage and mitigate abandoned, lost, and discarded fishing gear at-sea. [6] The company Net-works worked out a solution to turn discarded fishing nets into carpet tiles. [17]
Between 2008 and 2015, the US Fishing for Energy initiative collected 2.8 million pounds of fishing gear, and in partnership with Reworld turned this into enough electricity to power 182 homes for one year by incineration. [5] [18]
One retrieval initiative in Southwest Nova Scotia in Canada conducted 60 retrieval trips, searched ~1523 square kilometers 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. [19]
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. [20] In 2020 the Ghost Fishing Foundation rebranded as the Ghost Diving Foundation. [21]
A plan to protect UK seas from ghost fishing was backed by the European Parliament 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". [22]
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. [23]
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. [24] Recycled waste nets can be made into yarn and consumer products, such as swimwear. [25] [26]
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. [27]
General:
1
Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment, but may also be caught from stocked bodies of water such as ponds, canals, park wetlands and reservoirs. Fishing techniques include hand-gathering, spearing, netting, angling, shooting and trapping, as well as more destructive and often illegal techniques such as electrocution, blasting and poisoning.
Trawling is an industrial method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different species of fishes or sometimes targeted species. Trawls are often called towed gear or dragged gear.
Longline fishing, or longlining, is a commercial fishing angling technique that uses a long main line with baited hooks attached at intervals via short branch lines called snoods or gangions. A snood is attached to the main line using a clip or swivel, with the hook at the other end. Longlines are classified mainly by where they are placed in the water column. This can be at the surface or at the bottom. Lines can also be set by means of an anchor, or left to drift. Hundreds or even thousands of baited hooks can hang from a single line. This can lead to many deaths of different marine species. Longliners – fishing vessels rigged for longlining – commonly target swordfish, tuna, halibut, sablefish and many other species.
Bycatch, in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juveniles of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting. Non-marine species that are caught but regarded as generally "undesirable" are referred to as rough fish or coarse fish.
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 generally referred to as a "cork line." The line along the bottom of the panels is generally weighted. Traditionally this line has been weighted with lead and may be referred to as "lead line." A gillnet is normally set in a straight line. Gillnets can be characterized by mesh size, as well as colour and type of filament from which they are made. Fish may be caught by gillnets in three ways:
Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions. Large-scale commercial fishing is called industrial fishing.
A fishing net is a net used for fishing. Some fishing nets are also called fish traps, for example fyke nets. Fishing nets are usually meshes formed by knotting a relatively thin thread. Early nets were woven from grasses, flaxes and other fibrous plant material. Later cotton was used. Modern nets are usually made of artificial polyamides like nylon, although nets of organic polyamides such as wool or silk thread were common until recently and are still used.
Lobsters are widely fished around the world for their meat. They are often hard to catch in large numbers, but their large size can make them a profitable catch. Although the majority of the targeted species are tropical, the majority of the global catch is in temperate waters.
Marine debris, also known as marine litter, is human-created solid material that has deliberately or accidentally been released in seas or the ocean. Floating oceanic debris tends to accumulate at the center of gyres and on coastlines, frequently washing aground, when it is known as beach litter or tidewrack. Deliberate disposal of wastes at sea is called ocean dumping. Naturally occurring debris, such as driftwood and drift seeds, are also present. With the increasing use of plastic, human influence has become an issue as many types of (petrochemical) plastics do not biodegrade quickly, as would natural or organic materials. The largest single type of plastic pollution (~10%) and majority of large plastic in the oceans is discarded and lost nets from the fishing industry. Waterborne plastic poses a serious threat to fish, seabirds, marine reptiles, and marine mammals, as well as to boats and coasts.
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 weights attached to another rope along the bottom of the net. Drift nets generally rely on the entanglement properties of loosely affixed netting. Folds of loose netting, much like a window drapery, snag on a fish's tail and fins and wrap the fish up in loose netting as it struggles to escape. However, the nets can also function as gill nets if fish are captured when their gills get stuck in the net. The size of the mesh varies depending on the fish being targeted. These nets usually target schools of pelagic fish.
Unsustainable fishing methods refers to the use of various fishing methods to capture or harvest fish at a rate that is unsustainable for fish populations. These methods facilitate destructive fishing practices that damage ocean ecosystems, resulting in overfishing.
The environmental impact of fishing includes issues such as the availability of fish, overfishing, fisheries, and fisheries management; as well as the impact of industrial fishing on other elements of the environment, such as bycatch. These issues are part of marine conservation, and are addressed in fisheries science programs. According to a 2019 FAO report, global production of fish, crustaceans, molluscs and other aquatic animals has continued to grow and reached 172.6 million tonnes in 2017, with an increase of 4.1 percent compared with 2016. There is a growing gap between the supply of fish and demand, due in part to world population growth.
Fishing techniques are methods for catching fish. The term may also be applied to methods for catching other aquatic animals such as molluscs and edible marine invertebrates.
Marine plastic pollution is a type of marine pollution by plastics, ranging in size from large original material such as bottles and bags, down to microplastics formed from the fragmentation of plastic material. Marine debris is mainly discarded human rubbish which floats on, or is suspended in the ocean. Eighty percent of marine debris is plastic. Microplastics and nanoplastics result from the breakdown or photodegradation of plastic waste in surface waters, rivers or oceans. Recently, scientists have uncovered nanoplastics in heavy snow, more specifically about 3,000 tons that cover Switzerland yearly.
A wild fishery is a natural body of water with a sizeable free-ranging fish or other aquatic animal population that can be harvested for its commercial value. Wild fisheries can be marine (saltwater) or lacustrine/riverine (freshwater), and rely heavily on the carrying capacity of the local aquatic ecosystem.
This page is a list of fishing topics.
The following outline is provided as an overview of and topical guide to fishing:
This is a glossary of terms used in fisheries, fisheries management and fisheries science.
Beach cleaning or clean-up is the process of removing solid litter, dense chemicals, and organic debris deposited on a beach or coastline by the tide, local visitors, or tourists. Humans pollute beaches with materials such as plastic bottles and bags, plastic straws, fishing gear, cigarette filters, six-pack rings, surgical masks and many other items that often lead to environmental degradation. Every year hundreds of thousands of volunteers comb beaches and coastlines around the world to clean this debris. These materials are also called "marine debris" or "marine pollution" and their quantity has been increasing due to anthropocentric activities.
Christine Figgener is a German marine conservation biologist, author, science communicator, and ocean advocate recognized for her work in sea turtle conservation, the fight against plastic pollution, and the empowerment of women in STEM. She is best known for documenting the removal of a plastic straw from a sea turtle's nose in a YouTube video that went viral in 2015. This video, which was featured in popular media outlets such as National Geographic, HuffPost, The New York Times, ABC News, and CNN, highlighted the dangers of plastic pollution on marine wildlife and was a catalyst for the global anti-straw movement that led to several straw bans by businesses such as Starbucks, Disney, and Alaska Airlines.