Problems Caused by Polyethylene Terephthalate to the Chromis Viridis Fish
Plastic particles on the micro and macro scale continue to increase in the environment, both due to product usage, increased industrial production, and the breakdown of larger plastic rubbles. The toxic effects of plastic particles are a result of their chemical composition, uptake as well as binding with environmental pollutants, or the extent to which they are taken up by fish. Plastic use has significantly increased worldwide in the last few decades, with more than 299 million tons recorded in 2013. Polyethylene terephthalate (PET) is used in softening vinyl products, including vinyl clothing, footwear, emulsion paint, product packaging, printing ink, surgical gloves, inhalation masks, and breathing tubes. PET is also used in making water and soda bottles, chewing gum, drinking glasses, toys, food containers, plastic bags, heat-sealed plastic, and squeeze bottles. The blue-green Chromis Viridis examined in this study feeds on, flakes as well as pellets; specifically, it relies on shrimps, copepods, amphipods, polychaetes, fish larvae, and fish eggs. This study found out that it is possible for PET to cause developmental and mechanical problems to Chromis Viridis based on the information regarding feeding, gaseous exchange, and use of appendages. Nonetheless, there is a need for further experimental research to validate the claims.
Problems Caused by PET to the Blue-Green Chromis Viridis Fish in Sea Water
Plastic particles on the micro and macro scale continue to increase in the environment due to product usage, increased industrial production, and breakdown of larger plastic rubbles. While the particles contain various organic pollutants such as plasticizers, they can also bind with other environmental pollutants from the water. The chemicals along with other microparticles are harmful. This project seeks to determine if the plastic chemical called polyethylene terephthalate (PET) causes developmental and/or mechanical problems in blue green Chromis viridis fish when deposited in sea water.
The relevance of This Study
The increased ties with marine environments have resulted in the identification of various factors of chemical contamination. Plastic particles that originate from industry powders and resins or chemical and mechanical breakdown of macro plastic have been increasing in the environment. The toxic effects of plastic particles are a result of their chemical composition, uptake as well as binding with environmental pollutants, or the extent to which they are taken up by fish.
Plastics are used in various products ranging from industrial applications to personal care to textile products and have the potential for intelligent solutions in the future for as environmental friendly applications. Plastic use has increased significantly worldwide in the last few decades, with more than 299 million tons recorded in 2013 (Greenpeace Research Laboratories, 2016). The disadvantage of the substances is the resulting waste. For many years, there has been an awareness regarding the problems of plastic debris both in scientific and public communities. On average, plastic debris makes up between 60 and 80 percent of marine waste, and in some areas, the concentration is even higher, at 95 percent. As much as 100,000 particles per m2 on some shorelines as well as up to 350,000 items per km2 on some ocean surfaces are made up of plastic (Bathanie, 2013). The plastic debris deposited on shorelines and sea surfaces cause immediate threats when consumed by sea animals such as fish, birds, turtles, and mammals. Nonetheless, there is an increasing sign that environmental plastics are likely to continue in the environment at smaller sizes.
Discarded plastic may be landfilled, recycled, or incinerated. However, there are others that find their way into oceans as well as other waterways through urban drainage, deliberate garbage dumping, runoff, accidental spillage, or effluents from wastewater and sewage treatment plants (Greenpeace Research Laboratories, 2016). There is so much attention to tiny pieces of microplastics because their effect can be more significant than that of macro-plastics. Carelessly discarded waste plastic is likely to affect marine animals through choking, strangulation, entanglement, and malnutrition. Given the small size of microplastics, they can be ingested in large numbers and could also be adsorbed and desorbed. Hazardous components of plastic debris include chemical ingredients, physical components as well as adsorbed environmental chemicals such as persistent and bioaccumulative substances and metals. Once plastics are in a microscopic form as fragments of larger pieces or intentionally manufactured microbeads, there are some that can adsorb toxic or bioaccumulative pollutants from seawater, including persistent organic pollutants, which bioaccumulate in tissues and resist degradation. The impact of the existence of the pollutants in the natural environment has been recorded both on wildlife and humans. Polyproylene and polyethylene are among the most likely organic pollutants that accumulate in their environments (Greenpeace Research Laboratories, 2016). Once ingested, microscopic plastic segments are translocated into tissues resulting in increased granulocytomas or decreased stability of lysosomal membrane (Bathanie, 2013). Persistent bioaccumulative and toxic substances are linked with various adverse effects such as decreased fish populations.
Moreover, plastic particles may be a result of organic chemicals. Plastics can leach chemical compounds, including anti-microbials, ultraviolet stabilizers, plasticizers, dioxins as well as flame retardants, which are toxic and remain of a serious environmental concern. Plastic additives can be leached resulting in disruption of the endocrine system through toxicity. Furthermore, plastics found in marine environments may act as sinks for organic pollutants, which specially bind to plastic particles as a result of their hydrophobic nature (Greenpeace Research Laboratories, 2016). The particles then find their way into wildlife through ingestion, resulting into toxic effects of the chemicals, which include hormone disruption, oxidative stress, carcinogenicity, and immunosuppression.
Fish, which is one of the largest and most diverse groups of animals and holds ecological and commercial significance, are useful indicators of stressors in aquatic habitats. Moreover, plastic particles have been identified in the gut content of various fish species worldwide, including estuaries, pelagic habitats, and bays. Polyethylene has a higher affinity for organic contaminants compared to other polymers, remains the most largely produced plastic globally, and is one of the most common polymers that have been recovered as aquatic debris. Fish exposed to marine and virgin plastic treatments have recorded signs of stress in their liver, such as fatty vacuolation, glycogen depletion as well as single cell necrosis.
Based on this background information, it is apparent, that chemicals in plastics have detrimental effects on the lives of marine environment creatures. When waste plastics are not properly discarded, their detrimental effects come in forms such as strangulation, choking, entanglement, and malnutrition to marine animals. Similarly, there have been reports of glycogen depletion, cell necrosis, and glycogen depletion.
Categorization of Plastics
Plastic products are in five main categories, namely polyvinyl chloride (PVC), polyethylene, polypropylene, and polyethylene terephthalate (PET). When plastics are broken down, they form microparticles and nanoparticles, which pose additional threats to wildlife. The threats are a result of the ingested particles. The information that fish ingest plastics helps in understanding the effect of plastic particles, particularly on the environment as well as on making predictions regarding their interactions with fish biology (Greenpeace Research Laboratories, 2016). Furthermore, filter feeders usually take up plastic particles, which pose problems to them, and provide mechanisms through which plastics enter fish through the food web. Bis-2-ethylxylphlate is used in polyvinyl chloride production while bisphenol A is a plastic additive. The compounds are known to inhibit growth and disrupt hormones as well as affect reproduction and embryonic development of fish.
Bisphenol-A (BPA) is a monomer that is used in the production epoxy resins, and polycarbonate plastics are a potential endocrine disruptor. There have been concerns that BPA causes toxicity during development, particularly in infants and unborn children (Greenpeace Research Laboratories, 2016). Phthalate esters function as softeners that make plastics more flexible, particularly polyvinyl chloride. The esters also act as fragrance or solvent fixers in cosmetics and perfumes. Of note, there are phthalates that are toxic to reproduction while others damage the liver when taken at high doses.
Nonylphenol functions as an antioxidant, stabilizer, and plasticizer. This chemical is very toxic to aquatic animals besides being an endocrine disruptor in fish, with possibility of causing feminization. Polybrominated diphenyl esters (PDBEs) act as fire retardants and are used in plastics, textiles, and foams. These chemicals are possible endocrine disruptors, particularly to the thyroid function. There have been concerns regarding the effect of PDBEs on neurological development and behavior of the liver and the immune system (Greenpeace Research Laboratories, 2016). Polychlorinated biphenyls (PCBs) were initially used as flame retardants and fluid insulators in transformers (Greenpeace Research Laboratories, 2016). PCBs are toxic to the immune system as well as developing nervous systems in various animals.
Overview of Poly (Ethylene Terephthalate) (PET)
Poly (ethylene terephthalate) (PET) is a semi-crystalline thermoplastic polyester, which different companies manufacture using different trade names (Webb, Arnott, Crawford & Ivanova, 2013). PET is strong, durable, chemically stable, thermally stable, and easily permeated by gases. When combined, the properties make PET a suitable material for many applications and a substantial component of worldwide plastic consumption (Webb et al., 2013). Phthalates are used in softening vinyl products, including vinyl clothing, footwear, emulsion paint, product packaging, printing ink, surgical gloves, inhalation masks, and breathing tubes (Webb et al., 2013). The chemicals cause endocrine disruption and reproductive effects. Finally, polyethylene is used in making water and soda bottles, chewing gum, drinking glasses, toys, food containers, plastic bags, heat-sealed plastic, and squeeze bottles (Webb et al., 2013).
Overview of the Blue-Green Chromis Viridis Fish
The Green Chromis is a small fish that is characterized by uniform pale green coloration that may have a blue tint. Its natural environment is the Indo-Pacific region where they live in large aggregations. They live in relatively shallow waters with a maximum depth of approximately 36’ deep in lagoons. The blue green Chromis viridis feed on meaty foods, flakes as well as pellets; specifically, they rely on shrimps, copepods, amphipods, polychaetes, fish larvae, and fish eggs. They have also been reported to eat filamentous algae and zooplankton. These fish have fins and gills for gaseous exchange.
Effects of Microplastic on Marine Biota
Plastic particles have their effect as a result of various possible factors relating to chemical and physical effects. Particle size and shape are important when examining physical effects; while for chemical effects, large surface area and reactivity along with intrinsic toxicity and adsorption are worth examining (GESAMP, 2015). Smaller particles usually have large surface area per unit mass, and therefore, show more intrinsic toxicity. Microplastic particles with less than 100 micrometers are thus considered to have a higher likelihood of causing chemical effects on marine organisms (GESAMP, 2015). Similarly, microplastic shapes can range from spheres to fibers with varied surface roughness and sizes that include fine particles to ultrafine particles. There is also a possibility that nanoparticle sizes occur in the environment. The toxicities that are caused by nanoparticles are diverse.
External exposure to microplastic occurs when the outer surfaces of organisms such as gills come into contact with microplastic (GESAMP, 2015). Afterward, the microplastic may be translocated into an organism from the external. The level of exposure often depends on the concentration as well as size distribution of the microparticles as well as the explicit nature of the organism. For nearly all animals that are active feeders, external exposure of microplastics is smaller than exposure through ingestion. In marine organisms that do not rely on filter feeding, ingested microspheres are retained within the body tissues for up to 14 days after ingestion (GESAMP, 2015).
It has been shown that microplastics are ingested by many of the marine taxa representing different trophic levels such as fish-eating birds, fish, marine mammals as well as invertebrates. Ingestion of plastic particles has been reported in nearly all oceanic regions as well as in numerous species, including pelagic and benthic fish, nephrops, pelagic planktivorous fish, pelagic piscivorous fish, marine mussels, stranded whales, franscicana dolphins, fulmars, wedge-tailed shearwaters, harbour seals, and magellanic penguins (GESAMP, 2015). Invertebrates ingesting microplastics include deposit feeding lungworms, sea cucumbers, sponges, echinoderms, polychaetes, bivalves, and bryozoans (GESAMP, 2015). There is also an evidence of planktonic organisms consuming microplastics apart from salps, for instance, larval fish and arrow worms. Microscopic polystyrene particles ingested by mussels have been found in the gut prior to being translocated to the circulatory system before eventual uptake by hemocytes. There is also an intracellular uptake of microplastic into the cells of digestive tubules and subsequent transition into cell organelles of the lysosomal system (GESAMP, 2015). Whenever plastic accumulates inside the lysosomes, with such accumulation corresponding with breakdown of the lysosomal membrane into the cytoplasm, the end result is always cell death. It is, therefore, appropriate to argue that in vivo exposure to microplastic due to physiological strategies that are involved in the process of feeding results in nanoparticle uptake by gills and subsequent translocation to the digestive gland where the materials taken up induce lysosomal distresses (GESAMP, 2015).
Once microplastics have been assimilated into the tissues or hemolyph of an organism, they can accumulate or be excreted based on their compositions, sizes, and shapes. If accumulated, physical and chemical effects are developed and maintained for a long time. However, if the particles are excreted, then the processes are reversed in a process of healing and regeneration. Microplastic concentrations can peak in the hemolyph even after a single discrete exposure. Nonetheless, microparticle is retained in the gut for up to 12 days, with small-sized particles having a higher retention time than larger ones (GESAMP, 2015).
Moreover, microplastics can be transferred into the food web when predators consume prey. Microplastics have been found in the stomach, gills, hepatopancrease, and ovaries of the animals predated on such species as crabs. Likewise, polystyrene microspheres ingested by zooplanktons have been found in shrimps after ingestion, indicating transfer of microplastics across the trophic. Microplastic particles identified in the gastrointestinal tracts of different fish species is an indication of prey activities (GESAMP, 2015).
It is apparent that microplastics have become common and global in the marine environment. Adverse effects of microplastics on marine organisms arise from physical obstruction and damages caused to feeding appendages or physical harm or damage to digestive tract (GESAMP, 2015). Besides, microplastics may act as vectors for transporting chemicals into marine organisms, resulting in chemical toxicity. Microplastics translocated to other tissues from the gut may cause internal exposure and subsequent particle toxicity or particle-dependent chemical toxicity when chemicals are leached. Microplastics could also act as carriers for dispersal of chemicals and invasive species and pathogens, which endanger marine biodiversity (GESAMP, 2015).
Small-sized plastic particles are available in a wide range of marine organisms, thereby posing possible threat to the biota. This is usually the case with suspension feeders, including zooplanktons, crustaceans, bivalves, and polychaetes (GESAMP, 2015). Direct effects occur following ingestion and translocation into cells, tissues, and body fluids that cause particle toxicity. Investigations on the impacts of microplastics on marine organisms have focused on invertebrates and fish. Sorption of nanoparticles to algae hinders algal photosynthesis and induces oxidative stress. Microplastics adhere to the external appendages and carapace of zooplanktons, resulting in decreased function or algal feeding (GESAMP, 2015). There have also been instances of reduced fitness and bioaccumulation of organisms. The next section, therefore, provides a summary of studies that have been conducted before and are pertinent to the study topic.
The literature provided here highlights the most recent scientific and technical reports on how plastics affect the marine environment. The study by Rochman, Hoh, Kurobe & Teh (2013) sought to determine whether ingested plastic can transfer hazardous chemicals to fish and induce hepatic stress. This study was conducted following a report by the United Nations, which showed that more than 50 percent of plastics were characterized by hazardous additives, monomers, and chemical byproducts. Because persistent bioaccumulative and toxic substances isolated from plastic debris, bioaccumulate plastic debris associated with adverse effects such as decreased fish populations. The authors were concerned that there was a poor understanding regarding the extent to which chemicals associated with plastic debris through manufacturing process or environmental bioaccumulate in animals after ingestion. There was also a concern about the health hazards that wildlife were exposed to due to the complex mixture of plastic materials as well as chemicals that were associated with plastic materials. The chemical and physical hazards highlighted alongside increased ingestion of plastic by different aquatic organisms across different trophic levels, and evidence supporting chemical transfer to wildlife from plastics prompted the study.
The hypothesis of the study by Rochman and colleagues (2015) was that PAHs, PCBs, and PBDEs are transferred from the tissue of fish following the ingestion of marine-plastic material. One of the findings of this research was that polyethylene sorbs more PCBs and PAHs than other polymers. The other finding was that there was a greater concentration of PBTs in the fish that were exposed to marine plastic than in fish that received virgin and control treatments. The concentrations were higher after a long-time exposure. Therefore, a short-time exposure to plastic diet may not contribute to significant amounts of PBTs in the aquatic life (Rochman et al., 2015).
Hypothesis on adverse health effects, particularly in fish, was mainly on the sublethal effects on liver that followed plastic ingestion. Glycogen was depleted severely in fish that had been treated with plastic from the marine environment; in fact, the rate of depletion was 74 percent while fish from virgin plastic recorded 46 percent glycogen depletion and virgin treatment recorded no glycogen depletion. On the other hand, fish that had been treated with marine plastic recorded 47 percent fatty vacuolation while virgin plastic treated fish recorded 29 percent fatty vacuolation and control treatment had 21 percent fatty vacuolation. Single cell necrosis was evident in 11 percent fish treated with marine plastic while virgin and control treatments had no cell necrosis. Even though this study focused on a medaka fish model, the investigators noted that several other fish models in the wild also ingest plastic debris (Rochman et al., 2015). A notable aspect of this study is that the fish were exposed to mixtures of chemicals through plastic ingestion. Using histology, the investigators recorded severe glycogen depletin, cellular necrosis, cellular lesions, and fatty vacuolation. The conclusion, therefore, was that polyethylene ingestion is a route for bioaccumulation of PBTs in fish with toxicity coming through plastic ingestion being due to the sorbed contaminants as well as the plastic material.
On the other hand, Avio, Gorbi and Regoli (2015) conducted a study that was meant to experiment with the development of a new protocol that would help in extracting and characterizing microplastics found in fish tissues. The investigators conducted the study after the realization that various organisms are able to ingest microplastics, which can potentially cause adverse effects on the respiratory system, the digestive system as well as movement appendages. Nonetheless, the investigators indicated that at the time of conducting the study, there was no clear evidence regarding tissue accumulation or transfer of the microparticles in wild organisms. Therefore, in their study, the investigators compared the efficacies of the approaches for extracting microplastics from tissues of various fish based on the polymer size. They were able to extract microplastics from fish tissues that were ranging from 78 percent to 98 percent, depending on the size of the polymer. The isolated microparticles were those of polyethylene and polystyrene, and they were noted to have originated from the stomach, liver, and hepatic tissues. The fish species used in the experiment had been collected from the Adrian Sea (Avio et al., 2015). Therefore, it is evident from the findings of this investigation that microplastics can be translocated from the gastrointestinal tract to the liver of fish.
In another study, Mattssson et al. (2015) conducted an investigation to determine if there was an altered behavior, physiology, as well as metabolism in fish that were exposed to polystyrene nanoparticles. The investigators acknowledged that nanoparticles are used in many of the consumer products, including cosmetics, sunscreen, and electrical devices. Besides, there was a realization that many more plastic waste products were entering the natural ecosystems, including lakes and oceans. The nanoparticles were administered through an aquatic food chain, from algae to Daphnia, and observations were made on the behavior as well as metabolism. The investigators found that the feeding and shoaling behaviors were severely affected as well as metabolism, thus the conclusion that nanoparticles have severe effects on behavior and metabolism of fish. The study showed that microplastics result in fish feeding for a longer time, becoming less active and spending more time in their shoal and less time making explorations (Mattsson et al., 2015).
Analysis of how Polyethylene Terephthalate (PET) Could Cause Development and/or Mechanical Problems in Chromis Viridis Fish
The analysis of possible effect of PET on developmental and chemical problems focuses on the mode of feeding, use of appendages, and gaseous exchange structures. It has been noted that the blue green Chromis viridis are omnivores feeding on meaty foods, flakes as well as pellets. These fish specifically rely on shrimps, copepods, amphipods, polychaetes, fish larvae, and fish eggs. Chromis viridis have also been reported to eat filamentous algae and zooplankton. Concerning appendages, the fish have fins for movement and maintaining balance while in water while the gills are used for gaseous exchange.
Setälä, Fleming-Lehtinen & Lehtiniemi (2014) conducted experiments using different sea zooplankton taxa to observe ingestion as well as transfer of microplastics in the food web. The findings of this study can be used to support the argument that PEP causes development and mechanical problems to fish. In the study, mysid shrimps, cladocerans, rotifers, copepods, ciliates, and polychaetes were exposed to microspheres. The highest percentage of ingested spheres was in pelagic polychaete larvae while mysid shrimp showed egestion of microspheres. The study showed that there is a potential of transferring plastic microparticles from one trophic level to another. It can be argued that since Chromis viridis feeds on polychaetes, there is a likelihood of PET being transferred via food chain, thus causing a developmental problem; however, this has to be proven experimentally. The trophic level transfer of microplastics from zooplankton to the mysid shrimp, both of which are food for the Chromis viridis, should serve as an indication of impending problems. Microplastics ingested by viridis after feeding on the other aquatic creatures such as zooplanktons and shrimps that serve as food can transfer problems such as toxicity, which not only can hinder developmental processes, but also can cause mechanical problems.
Small-sized microplastics such as PET are available for various marine organisms, thereby posing a significant threat to biota. Small-size deposit feeders such as zooplankton, polychaetes, and bivalves, which are fed on by Chromis viridis, may pose mechanical hazards after ingesting the plastics. Physical effects can also be through entanglement, obstruction of feeding organs, reduction of feeding capacity, or adsorption of microplastics, for instance, algae and zooplankton. Direct effect on Chromis viridis may occur after ingesting and translocating PET microparticles into tissues, cells, and body fluids, resulting in particle toxicity (GESAMP, 2015). Microplastic adheres to external appendages of aquatic wildlife. Therefore, it is possible that appendage-like structures in Chromis viridis, for instance, the fins, can be obstructed by the microplastic particles of PET. It is also important to remember that PET is among the commonest microplastics deposited in the marine environment.
It has been shown that microspheres found within copepods are transferred after being ingested by mysid shrimps. This further demonstrates possible trophic level transfer of microplastics, including polyethylene terephthalate. Importantly, Chromis viridis feed on both mysid shrimps and copepods, increasing the possibility of transferring the microplastics and toxic effects via the two food sources.
Gaseous exchange in Chromis viridis occurs through the gills. It should, however, be noted that exposure to microplastics can occur through the gills. Afterwards, microplastics are translocated from the outside into the organism. The level of external exposure depends on the concentration as well as size distribution of the particles and the nature of the organism. Physiological mechanisms that are involved in the process of feeding agglomerate nanoparticles that are taken up by the gills and later directed to the digestive glands where intracellular uptake of the small-sized materials would induce lysosomal perturbations. Similarly, diffusive uptake of dissolved plastic organic particles such as those of PET can occur following transfer from food to Chromis viridis. Under the right condition, marine organisms such as viridis will ingest microplastic particles (GESAMP, 2015). As a consequence, it is probable to translocate PET microplastics through the gills to cause mechanical and developmental problems.
Xenobiotic microplastic particles such as PET can accumulate in the organs and tissues of the blue green fish. Once the buildup has increased to significant proportions, they can induce an immune response, granuloma formation, and foreign body reaction. Such direct particle toxicity results from microplastic translocation from gut to body fluids into cells, organs, and even organelles. Accumulation of plastic inside lysosome and the breakdown of lysosomal membrane as well as release of degrading enzyme into the cytoplasm can cause cell death. Besides, strong immune response can occur where particles are expelled from the digestive tubules into storage tissues. Macrophages that engulf plastics have been shown to be encapsulated by fibrous tissue, triggering the formation of granulocytoma. Proliferation of granulocytes and basophilic hemocytes indicate strong immune response that has also been observed in the digestive gland of aquatic animals (GESAMP, 2015).
Based on the analysis provided regarding the effect of polyethylene terephthalate (PET) on development and/or mechanical problems in Chromis viridis fish, the one thing that is evident is the lack of adequate previous supporting evidence. However, it is important to rely on Chromis viridis feeding mechanisms, gaseous exchange, and use of appendages in its aquatic environment to show microplastic; particularly, PET would cause developmental and mechanical problems.
· There is a need for more research on the physical effects of polyethylene terephthalate on the gut and tissue of Chromis Viridis fish. There is currently very limited research on this aquatic fish. The methods of choice for detecting and analyzing microplastics, including PET, would need to carefully consider prior experimentation so as to support comparison with other studies.
· It is important to determine the extent of bioaccumulation of PET and other toxic chemicals in Chromis viridis that have ingested microplastics as well as the level of plastic organic particles to transfer on a trophic level.
· It is important to determine the sublethal effect on Chromis viridis of polyethylene terephthalate as well as sublethal quantity of microplastic ingestion.
· There is a need to have protocols that accurately identify polyethylene terephthalate and associated toxic effects on Chromis viridae tissue. Such protocols need to be standardized, because through that, it will be easy to estimate levels of exposure as well as formulate risk assessments.
· There is a need for an estimate for field data to access the quantity of polyethylene terephthalate containing plastics in the aquatic environment, inclusive of sources, how the fish and other animals move with currents, and their sink rate. It is also necessary to determine the rate of breakdown as well as distribution of PET of different sizes after they have entered the aquatic environment.
· There is a need for further research to determine the extent to which polyethylene terephthalate crosses membranes and cell walls in Chromis viridis. It is also critical to examine further how polyethylene terephthalate increases the stress burden in Chromis viridis as well as other organisms.
· It is important to determine if Chromis viridis accidentally or actively ingest microplastics, particularly polyethylene terephthalate.
Most microplastic particles consist of six major polymers, including polyethylene, polypropylene, and polystyrene, which are likely to float. There are also polymers of polyvinyl chloride, polyethylene terephthalate, and plyamide, which are more likely to sink. Plastics absorb and concentrate hydrophobic derived from the surrounding sea water. Furthermore, additive chemicals that are incorporated during manufacture represent significant proportion of the particle composition. Once the microplastics have entered the sea water, they become globally distributed on surface water, beaches, seabed sediments as well as in various biota, including fish, birds, mammals, and invertebrates from the Arctic to the Antarctic. The particles then become concentrated in locations such as ocean gyres after long-distance transport, shipping routes, and population centers.
Polyethylene terephthalate (PET), a strong, durable, chemically stable, thermally stable, and easily permeated by gases polymer, is used in softening vinyl products, including vinyl clothing, footwear, emulsion paint, product packaging, printing ink, surgical gloves, inhalation masks, and breathing tubes. PET is associated with endocrine disruption and reproductive effects. Polyethylene is also used in making water and soda bottles, chewing gum, drinking glasses, toys, food containers, plastic bags, heat-sealed plastic, and squeeze bottles. The blue green Chromis viridis that is examined in this study feeds on a variety of food sources, including flakes, pellets, shrimps, copepods, amphipods, polychaetes, fish larvae, and fish eggs. These fish have also been reported to feed on filamentous algae and zooplankton. These fish have fins and gills for gaseous exchange.
The blue green Chromis viridis have appendages such as fin,s which they use for movement and maintaining balance in water, and the gills are used for gaseous exchange. Based on the results of experiments conducted so far, zooplankton fed on by Chromis viridis ingest and transfer microplastics, indicating the possibility that PEP may cause development and mechanical problems to fish. Microplastics ingested by viridis via zooplanktons and shrimp can transfer PET toxicity that enhances mechanical and developmental problems.
PET can also physically affect Chromis viridis through entanglement, obstruction of feeding organs, reduction of feeding capacity, or adsorption. Direct effect on Chromis viridis may occur after ingesting and translocating PET microparticles into tissues, cells, and body fluids, resulting in particle toxicity. Furthermore, microplastic adheres to external appendages of aquatic wildlife. Therefore, it is possible that appendage-like structures in Chromis viridis, for instance, the fins, can be obstructed by the microplastic particles of PET. It is important to remember that PET is among the commonest microplastics deposited in the marine environment.
Gills are used for translocation of materials from the outside into the organism. The level of external exposure depends on the concentration and the size of distribution of the particles as well as the nature of the organism, in this case, Chromis viridis. Physiological mechanisms involved in the process of microplastic feeding involve uptake by the gills and later direction to the digestive glands where the small-sized materials undergo intracellular uptake, thereby inducing lysosomal perturbations. Similarly, diffusive uptake of dissolved plastic organic particles such as those of PET can occur following transfer from food to Chromis viridis. Under the right condition, marine organisms such as viridis will ingest microplastic particles. As a consequence; it is probable to translocate PET microplastics through the gills to cause mechanical and developmental problems.