User:Ashley13530/Marine plastic pollution

Environmental impacts
The litter that is being delivered into the oceans is toxic to marine life, and humans. The toxins that are components of plastic include diethylhexyl phthalate, which is a toxic carcinogen, as well as lead, cadmium, and mercury.

Plankton, fish, and ultimately the human race, through the food chain, ingest these highly toxic carcinogens and chemicals. Consuming the fish that contain these toxins can cause an increase in cancer, immune disorders, and birth defects. '''However, these toxins are not only found in fish but also in staple foods, drinking water, table salts, toothpaste, and other kinds of seafood. These issues can be found in Indonesia, which is the second largest contributor of plastic waste, where human stools were collected from fishermen finding that 50% had concentrations of microplastics. Each human stool that had microplastics had a concentration between 3.33 to 13.99 µg of microplastic per gram of feces (µg/).'''

The majority of the litter near and in the ocean is made up of plastics and is a persistent pervasive source of marine pollution. In many countries improper management of solid waste means there is little control of plastic entering the water system. As of 2016, there are 5.25 trillion particles of plastic pollution that weigh as much as 270,000 tonnes. Since then, studies have found that the amount of plastic particles has increased to somewhere from 15 to 51 trillion particles in 2021. This plastic is taken by the ocean currents and accumulates in large vortexes known as ocean gyres. The majority of the gyres become pollution dumps filled with plastic.

Research on floating plastic debris in the ocean was the fastest-growing topic among 56 sustainability topics examined in a study of scientific publishing by 193 countries over 2011 to 2019. Over nine years, global research documenting this phenomenon ballooned from 46 (2011) to 853 (2019) publications.

Effects on animals
Plastic waste has reached all the world's oceans. This plastic pollution harms an estimated 100,000 sea turtles and marine mammals and 1,000,000 sea creatures each year. Larger plastics (called "macroplastics") such as plastic shopping bags can clog the digestive tracts of larger animals when consumed by them and can cause starvation through restricting the movement of food, or by filling the stomach and tricking the animal into thinking it is full. Microplastics on the other hand harm smaller marine life. For example, pelagic plastic pieces in the center of our ocean’s gyres outnumber live marine plankton, and are passed up the food chain to reach all marine life.

'''Fishing gear such as nets, ropes, lines, and cages often get lost in the ocean and can travel large distances which has negatively impacted many marine animals such as coral. The fishing gear is made up of non-biodegradable plastic in many different species of coral get tangled in which causes them to lose tissue and possibly die.'''

Plastic pollution has the potential to poison animals, which can then adversely affect human food supplies. Plastic pollution has been described as being highly detrimental to large marine mammals, described in the book Introduction to Marine Biology as posing the "single greatest threat" to them. Some marine species, such as sea turtles, have been found to contain large proportions of plastics in their stomach. When this occurs, the animal typically starves, because the plastic blocks the animal's digestive tract. Sometimes marine mammals are entangled in plastic products such as nets, which can harm or kill them.

Entanglement
Entanglement in plastic debris has been responsible for the deaths of many marine organisms, such as fish, seals, turtles, and birds. These animals get caught in the debris and end up suffocating or drowning. Because they are unable to untangle themselves, they also die from starvation or from their inability to escape predators. Being entangled also often results in severe lacerations and ulcers. It was estimated that at least 267 different animal species have suffered from entanglement and ingestion of plastic debris. It has been estimated that over 400,000 marine mammals perish annually due to plastic pollution in oceans. Marine organisms, such as coral get caught in discarded fishing equipment, such as ghost nets. Ropes and nets used to fish are often made of synthetic materials such as nylon, making fishing equipment more durable and buoyant. These organisms can also get caught in circular plastic packaging materials, and if the animal continues to grow in size, the plastic can cut into their flesh. Equipment such as nets can also drag along the seabed, causing damage to coral reefs.

Some marine animals find themselves tangled in larger pieces of garbage that cause just as much harm as the barely visible microplastics. Trash that has the possibility of wrapping itself around a living organism may cause strangulation or drowning. If the trash gets stuck around a ligament that is not vital for airflow, the ligament may grow with a malformation. Plastic’s existence in the ocean becomes cyclical because marine life that is killed by it ultimately decompose in the ocean, re-releasing the plastics into the ecosystem.

Animals can also become trapped in plastic nets and rings, which can cause death. Plastic pollution affects at least 700 marine species, including sea turtles, seals, seabirds, fish, whales, and dolphins. Cetaceans have been sighted within the patch, which poses entanglement and ingestion risks to animals using the Great Pacific garbage patch as a migration corridor or core habitat.

Ingestion
Many animals that live on or in the sea consume flotsam by mistake, as it often looks similar to their natural prey. Plastic debris, when bulky or tangled, is difficult to pass, and may become permanently lodged in the digestive tracts of these animals. Especially when evolutionary adaptions make it impossible for the likes of turtles to reject plastic bags, which resemble jellyfish when immersed in water, as they have a system in their throat to stop slippery foods from otherwise escaping. Thereby blocking the passage of food and causing death through starvation or infection.

Many of these long-lasting pieces end up in the stomachs of marine birds and animals, including sea turtles, and black-footed albatross. This results in obstruction of digestive pathways, which leads to reduced appetite or even starvation. In a 2008 Pacific Gyre voyage, Algalita Marine Research Foundation researchers began finding that fish are ingesting plastic fragments and debris. Of the 672 fish caught during that voyage, 35% had ingested plastic pieces.

With the increased amount of plastic in the ocean, living organisms are now at a greater risk of harm from plastic consumption and entanglement. Approximately 23% of aquatic mammals, and 36% of seabirds have experienced the detriments of plastic presence in the ocean. Since as much as 70% of the trash is estimated to be on the ocean floor, and microplastics are only millimeters wide, sealife at nearly every level of the food chain is affected. Animals who feed off of the bottom of the ocean risk sweeping microplastics into their systems while gathering food. Smaller marine life such as mussels and worms sometimes mistake plastic for their prey.

Larger animals are also affected by plastic consumption because they feed on fish, and are indirectly consuming microplastics already trapped inside their prey. Likewise, humans are also susceptible to microplastic consumption. People who eat seafood also eat some of the microplastics that were ingested by marine life. Oysters and clams are popular vehicles for human microplastic consumption. Animals who are within the general vicinity of the water are also affected by the plastic in the ocean. Studies have shown 36% species of seabirds are consuming plastic because they mistake larger pieces of plastic for food. Plastic can cause blockage of intestines as well as tearing of interior stomach and intestinal lining of marine life, ultimately leading to starvation and death.

Some long-lasting plastics end up in the stomachs of marine animals. Plastic attracts seabirds and fish. When marine life consumes plastic allowing it to enter the food chain, this can lead to greater problems when species that have consumed plastic are then eaten by other predators.

Multiple studies have found plastics and microplastics in the stomach contents of marine animals.

The ingestion of large amounts of plastic debris, such as fish nets and ropes, can lead to marine animal's deaths via gastric impaction.

Mammals and fish
A 2021 literature review published in Science identified 1,288 marine species that are known to ingest plastic. Most of these species are fish.

Sea turtles are affected by plastic pollution. Some species are consumers of jelly fish, but often mistake plastic bags for their natural prey. This plastic debris can kill the sea turtle by obstructing the oesophagus. Baby sea turtles are particularly vulnerable according to a 2018 study by Australian scientists.

Plastics are ingested by various species of whales, such as beaked whales, baleen whales, and sperm whales. They can mistake plastics for food and consume them accidentally when feeding on prey organisms that are gathered near plastics. Plastics can also enter their system if their prey already had synthetic plastic particles in their digestive tract via bioaccumulation. Large amounts of plastics have been found in the stomachs of beached whales. Plastic debris started appearing in the stomach of the sperm whale since the 1970s, and has been noted to be the cause of death of several whales. In June 2018, more than 80 plastic bags were found inside a dying pilot whale that washed up on the shores of Thailand. In March 2019, a dead Cuvier's beaked whale washed up in the Philippines with 88 lbs of plastic in its stomach. In April 2019, following the discovery of a dead sperm whale off of Sardinia with 48 pounds of plastic in its stomach, the World Wildlife Foundation warned that plastic pollution is one of the most dangerous threats to sea life, noting that five whales have been killed by plastic over a two-year period.

Some of the tiniest bits of plastic are being consumed by small fish, in a part of the pelagic zone in the ocean called the Mesopelagic zone, which is 200 to 1000 metres below the ocean surface, and completely dark. Not much is known about these fish, other than that there are many of them. They hide in the darkness of the ocean, avoiding predators and then swimming to the ocean's surface at night to feed. Plastics found in the stomachs of these fish were collected during Malaspina's circumnavigation, a research project that studies the impact of global change on the oceans.

A study conducted by Scripps Institution of Oceanography showed that the average plastic content in the stomachs of 141 mesopelagic fish over 27 different species was 9.2%. Their estimate for the ingestion rate of plastic debris by these fish in the North Pacific was between 12,000 and 24,000 tonnes per year. The most popular mesopelagic fish is the lantern fish. It resides in the central ocean gyres, a large system of rotating ocean currents. Since lantern fish serve as a primary food source for the fish that consumers purchase, including tuna and swordfish, the plastics they ingest become part of the food chain. The lantern fish is one of the main bait fish in the ocean, and it eats large amounts of plastic fragments, which in turn will not make them nutritious enough for other fish to consume.

Another study found bits of plastic outnumber baby fish by seven to one in nursery waters off Hawaii. After dissecting hundreds of larval fish, the researchers discovered that many fish species ingested plastic particles. Plastics were also found in flying fish, which are eaten by top predators such as tunas and most Hawaiian seabirds.

Deep sea animals have been found with plastics in their stomachs. In 2020, deep sea species Eurythenes plasticus was discovered, with one of the samples already having plastics in its gut; it was named to highlight the impacts of plastic pollution.

It was found in 2016–2017 that more than 35% of south Pacific Lanternfish had consumed plastic particles. When ingested by the fish, the chemical compounds found in these plastics cannot be digested. This can affect humans, as the Lanternfish is a food source for both salmon and tuna. Fish and whales may also mistake the plastic as a food source.

Birds
Plastic pollution does not only affect animals that live solely in oceans. Seabirds are also greatly affected. In 2004, it was estimated that gulls in the North Sea had an average of thirty pieces of plastic in their stomachs. Seabirds often mistake trash floating on the ocean's surface as prey. Their food sources often has already ingested plastic debris, thus transferring the plastic from prey to predator. Ingested trash can obstruct and physically damage a bird's digestive system, reducing its digestive ability and can lead to malnutrition, starvation, and death. Toxic chemicals called polychlorinated biphenyls (PCBs) also become concentrated on the surface of plastics at sea and are released after seabirds eat them. These chemicals can accumulate in body tissues and have serious lethal effects on a bird's reproductive ability, immune system, and hormone balance. Floating plastic debris can produce ulcers, infections and lead to death. Marine plastic pollution can even reach birds that have never been at the sea. Parents may accidentally feed their nestlings plastic, mistaking it for food. Seabird chicks are the most vulnerable to plastic ingestion since they can't vomit up their food like the adult seabirds.

Plasticosis is a type of fibrotic disease initially found in one species of bird in 2023. A great blue heron capturing a fish already caught in a plastic bag – birds and other wildlife regularly consume plastic when it gets entangled with or confused with food.

After the initial observation that many of the beaches in New Zealand had high concentrations of plastic pellets, further studies found that different species of prion ingest the plastic debris. Hungry prions mistook these pellets for food, and these particles were found intact within the birds' gizzards and proventriculi. Pecking marks similar to those made by northern fulmars in cuttlebones have been found in plastic debris, such as styrofoam, on the beaches on the Dutch coast, showing that this species of bird also mistake plastic debris for food.

Of the 1.5 million Laysan albatrosses that inhabit Midway Atoll, nearly all are likely to have plastic in their gastrointestinal tract. Approximately one-third of their chicks die, and many of those deaths are from plastic unwittingly fed to them by their parents. Twenty tons of plastic debris washes up on Midway every year with five tons ending up in the bellies of albatross chicks. These seabirds choose red, pink, brown, and blue plastic pieces because of similarities to their natural food sources. As a result of plastic ingestion, the digestive tract can be blocked resulting in starvation. The windpipe can also be blocked, which results in suffocation. The debris can also accumulate in the animal's gut, and give them a false sense of fullness which would also result in starvation. On the shore, thousands of birds corpses can be seen with plastic remaining where the stomach once was. The durability of the plastics is visible among the remains. In some instances, the plastic piles are still present while the bird's corpse has decayed.

Similar to humans, animals exposed to plasticizers can experience developmental defects. Specifically, sheep have been found to have lower birth weights when prenatally exposed to bisphenol A. Exposure to BPA can shorten the distance between the eyes of a tadpole. It can also stall development in frogs and can result in a decrease in body length. In different species of fish, exposure can stall egg hatching and result in a decrease in body weight, tail length, and body length.

A study found that in 1960 less than 5% of seabirds were found to have consumed waste material, while as of August 2015 that figure climbed to about 90%. It is predicted that by 2050, 99% of seabirds will have consumed such materials. Scientists studying the stomach contents of Laysan Albatross chicks report a 40% mortality rate before fledging. When the stomach contents were analyzed following necropsies, they were found to contain plastic waste. Not only do plastic pellets used in manufacturing worldwide absorb toxic chemicals such as DDT and PCBs from the water, but they can even leach chemicals such as biphenyl. It is estimated that up to 267 marine species are affected by plastic pollution.

Coral

'''Lost fish nets or ghost nets make up around 46% of what is known as the Great Pacific Garbage Patch and have had a negative impact on many different species of coral as they often accidentally trap themselves in these nets. These fishing nets have caused tissue loss, algae growth, and fragmentation of coral. In addition, as coral gets trapped in different types of fishing gear, this causes coral to develop stress as they are not in a favorable condition, which causes coral to break and die off. According to multiple research studies, Tubastraea micranthus is a type of coral species that appears to be the most impacted by fishing gear in the ocean because of its branches and its ability to grow on top of fishing gear such as nets, ropes, and lines.'''

Phytoplankton

'''In 2019 and 2020 there were week-long studies done in Australia along the Georges River to measure the number of microplastics. The purpose of these studies was to determine if phytoplankton living in the river were being affected by the microplastics in the water. The studies included the completion of microcosm experiments where water samples were collected in bottles from the river and then filtered. In addition, microplastic solutions were made along with the collection of phytoplankton from the same river. After the studies were complete, scientists found out that there were very high concentrations of microplastics in the river which have negatively impacted phytoplankton such as cyanobacteria.'''

'''As many different species of phytoplankton are being exposed to microplastics in the Georges River, not only does this impact the lives of the phytoplankton themselves, but also affects other animals in their food chain. Phytoplankton are primary producers; therefore, when microplastics are ingested, other living organisms in the environment that feed on phytoplankton also ingest microplastics.'''

Fin Whales

'''In the Mediterranean Sea, studies have been performed to determine how the number of microplastics on the surface level of the ocean has affected fin whale populations. In the study, researchers collected samples of microplastics during the day when there was little to no wave action. The plastic pieces collected from the samples were then observed under a microscope to determine their size and whether they were microplastics or mesoplastics. The fin whale population's habitat was then observed where the zooplankton population was measured along with sea surface chlorophyll levels within their habitat. The Tyrreno-ROMS model was used to measure the ocean current or gyres along with the sea surface temperatures in the fin whales' habitat within the Mediterranean Sea.'''

'''The results of the studies indicated that there were high levels of microplastics within the surface level of the Mediterranean Sea which is the fin whales' habitat and serves as the location of their food source mainly during the summer months. The results indicate that when fin whales search for food to eat on the surface level of the ocean, they often accidentally consume microplastics. These microplastics have many toxins and chemicals that could harm the fin whale if they consume them as these toxins are then stored in the tissues of the fin whale for long periods of time.'''

Other
A study from 2019 indicates that the large amounts of plastic in the Great Pacific garbage patch could affect the behavior and distribution of some marine animals, as they can act as fish aggregating devices (FAD). FADs can attract feeding cetaceans, thus increasing the risk of being entangled or ingesting additional plastic. NOAA's marine debris removal in 2014 The unaltered stomach contents of a dead albatross chick include a variety of plastic marine debris

Effects on humans
Further information: Microplastics § Humans

Nanoplastics can penetrate the intestine tissue in aquatic creatures and can end up in the human food chain by inhalation (breathing) or ingestion (eating), particularly through shellfish and crustaceans. Ingestion of plastics has been associated with a variety of reproductive, carcinogenic, and mutagenic effects. The most well-known organic synthetic compound used in many plastics is bisphenol A (BPA). It has been linked with autoimmune disease and endocrine disrupting agents, leading to reduced male fertility and breast cancer. '''Phthalate esters are also linked to causing reproductive effects due to being found in packing products for food. The toxins from phthalate esters affect the developing male reproductive system. Diethylhexyl phthalate is also suspected to disrupt the functions of the thyroid; however, studies are currently inconclusive.'''

Plastics in the human body can stop or slow down detoxification mechanisms, causing acute toxicity and lethality. They have the potential to affect the central nervous system and reproductive system, although this would be unlikely unless exposure levels were very high and absorption levels were increased. In vitro studies from human cells showed evidence that polystyrene nanoparticles are taken up and can induce oxidative stress and pro-inflammatory responses.

Background
'Plastic pollution was first found in central gyres, or rotating ocean currents in which these observations from the Sargasso Sea were included in the 1972 Journal Science. In 1986, a group of undergraduate students conducted research by recording how much plastic they came across on their ship while traveling across the Atlantic Ocean. Their research led to them being able to collect useful and long term data about plastic in the Atlantic Ocean along with Charles Moore being able to discover the Great Pacific Garbage Patch. In addition, the undergraduate students' research helped lead to the invention of the term "microplastics".'

Terminology
Microplastics

'''The term "microplastics" was first used by Richard Thompson in 2004 as he described microplastics to be small pieces of plastic, specifically less than 5 mm, that are found in the ocean and other bodies of water. After Thompson's invention of the term "microplastics", many scientists have conducted research to try to determine the effects that microplastics have in the ocean.'''

Plastic soup
The term "plastic soup" was coined by Charles J. Moore in 1997, after he found patches of plastic pollution in the North Pacific Gyre between Hawaii and California. This Great Pacific Garbage Patch had previously been described in 1988 by scientists who used the term neuston plastic to describe "The size fraction of plastic debris caught in nets designed to catch surface plankton (hereafter referred to as neuston plastic)", and acknowledged that earlier studies in the 1970s had shown that "neuston plastic is widespread, is most abundant in the central and western North Pacific, and is distributed by currents and winds".

'In 2006, Ken Weiss published an article in the Los Angeles Times'' which was the first to make the public aware about the effects that the Garbage Patch in the Pacific Ocean. Later in 2009, a group of researchers decided to go out into the Pacific Ocean to prove if the Garbage Patch was real or a myth. After days out on the sea, the research group came across hundreds of plastic pieces in the ocean that were seen as a soup of microplastics rather than large pieces of plastics as expected.'''

The term is sometimes used to refer only to pollution by microplastics, pieces of plastic less than 5mm in size such as fibres shed from synthetic textiles in laundry: the British National Federation of Women's Institutes passed a resolution in 2017 headlined "End Plastic Soup" but concentrating on this aspect of pollution.

The Amsterdam-based Plastic Soup Foundation is an advocacy group which aims to raise awareness of the problem, educate people, and support the development of solutions.

As of January 2019, the Oxford English Dictionary did not include the terms plastic soup, neuston plastic or neustonic plastic, but it defined the term microplastic (or micro-plastic) as "Extremely small pieces of plastic, manufactured as such (in the form of nurdles or microbeads) or resulting from the disposal and breakdown of plastic products and waste" and its illustrative quotations all relate to marine pollution, the earliest being a 1990 reference in the South African Journal of Science: "The mean frequency of micro-plastic particles increased from 491 m1 of beach in 1984 to 678 m1 in 1989".