Investigating the presence of microplastics in demersal sharks of the North-East Atlantic

Abstract

Microplastic pollution is ubiquitous in the marine environment and is ingested by numerous marine species. Sharks are an understudied group regarding their susceptibility to microplastic ingestion. Here, we provide evidence of ingestion of microplastic and other anthropogenic fibres in four demersal sharks species found in the waters of the United Kingdom and investigate whether body burdens of contamination vary according to species, sex or size. Sharks were collected from the northEast Atlantic. Stomachs and digestive tracts of 46 sharks of 4 species were examined and 67% of samples contained at least one contaminant particle. Although we acknowledge modest sample size, estimated particle burden increased with body size but did not vary systematically with sex or species. A total of 379 particles were identified, leading to median estimates ranging from 2 to 7.5 ingested contaminants per animal for the 4 species. The majority were fibrous in nature (95%) and blue (88%) or black (9%) in colour. A subsample of contaminants (N = 62) were subject to FT-IR spectroscopy and polymers identified as: synthetic cellulose (33.3%), polypropylene (25%), polyacrylamides (10%) and polyester (8.3%). The level of risk posed to shark species by this level of contamination is unknown. Nevertheless, this study presents the first empirical evidence and an important baseline for ingestion of microplastics and other anthropogenic fibres in native UK shark species and highlights the pervasive nature of these pollutants. plastics in the marine environment. Research on plastic in the marine environment has accelerated rapidly in the last decade, with numerous publications describing its impact on ecosystems and marine taxa 1-7. It is estimated that between 4.8 and 12.7 million tonnes of plastic enter the oceans every year from a variety of sources 6. Plastic is a popular material due to its durability, low production cost and efficiency in its uses 8. It is these properties, alongside its often disposable nature that leads to its prevalence in the environment for many years 9. Microplastics (defined as plastic particles < 5 mm) 10 are ubiquitous in the marine environment 11-13. Despite this knowledge, quantitative assessments of their abundance are still fairly limited 14 , although some estimates place their abundance at 5.25 trillion particles globally, weighing in at over 250,000 tonnes 5. Microplastics, in the form of fibres, fragments or beads/spheres, assimilate in the marine ecosystem via multiple avenues. Larger pieces of plastic can disintegrate over time due to UV radiation exposure, wave action and physical abrasion, eventually fragmenting into microscopic particles 15. Microplastics are also found in many everyday items used by humans including cosmetic products and can be produced by clothing wear 16-19. These can then reach the oceans via wastewater treatment plants 20. ingestion of microplastics in marine species. Ingestion of microplastics is reported in many marine species including turtles, marine mammals and fish 1,21...

Effect of microplastics in water and aquatic systems

“…The presence of microplastics and fibres were found in the demersal shark species of united kingdom for the first time (Parton et al 2020). The major intake route of MP by sharks can be through its foods, which are mostly crustaceans and molluscs, or through direct feeding (Germanov et al 2019).…”

“…The major intake route of MP by sharks can be through its foods, which are mostly crustaceans and molluscs, or through direct feeding (Germanov et al 2019). Owing to the small particle size detected by the researchers, there is a chance of immediate excretion but however the presence of chemicals bound to the fibres can have repercussions on their reproductive cycle and immune systems (Parton et al 2020).…”

Microplásticos en peces marinos de importancia económica en Lima, Perú

“…Sin embargo, las especies evaluadas en el presente estudio no mostraron una relación entre las medidas biométricas con el número de partículas de MP/branquia. Tampoco se observó diferencias entre hembras y machos, resultado similar al obtenido por Parton et al (2020).…”

“…McNeish et al (2018) mencionan que la estrategia de alimentación de los peces está relacionada con la transferencia trófica de las partículas de plástico, por lo que estas especies podrían presentar un riesgo para otros organismos de diferentes niveles tróficos, peces de mayor tamaño, aves y mamíferos que se alimentan de otros peces, como S. deliciosa que se alimenta de la anchoveta (Parton et al, 2020;Weis, 2020). Calderón y Hansen (2018) mencionan que probablemente los peces omnívoros con preferencia a alimentos animales tengan una mayor abundancia de partículas MP, lo que coincidiría con este estudio, ya que S. gigas presentó 43.9/pez de MP.…”

Consequences of Exposure to Phthalates, Micro Plastics and Nano-Plastics on the Organisms

“…Particles were basically blue and dark (42.5% and 26.4%) in shading and Nylon was the most common (60%) polymer type (Nelmsw et al, 2018). Movement of moderately enormous (particles can happen over the vertebrate gut by means of per sorption (the section of particles through the epithelial layers of the gastro-intestinal lot), while littler particles are taken up through typical stomach related cycles (Parton et al, 2020). Ingested Micro and Nano plastic would initially experience the intestinal epithelium and aggravation of the gut lining.…”