Fiber micro-plastic cause damage to fish gills, aneurysms and increase the number of eggs in females, found researchers from the USA and China. A study published in the journal PLoS One.
One of the main components of the micro-plastic is a synthetic fiber, e.g. nylon, polyester, polypropylene and acrylic, which are used for the manufacture of fabrics. When washing the fibers fall into the sewage and ultimately into the ocean. According to some estimates, every year in the world’s oceans comes from 4.8 to 12.7 million tons of plastics, and the share of the micro-plastic accounts for about one third. Fibers in turn make up 90 percent of the micro-plastic.
The researchers found of microplastics in organisms of different animal species: microfiber was detected in 60 percent of the macroinvertebrates, in 49% of shore birds and various fish. During the life of the fish absorb a large number of microfibers. Earlier it was reportedthat fiber micro-plastic does not remain in the intestines of the fish longer than other food components, and the other a six-week experiment showedthat microfibers cause damage to the oral cavity and folds of intestine of fish.
However, in the body of the fish is not the only fiber that they eat. Hundreds or even thousands of fibers daily pass through their gills with water. The Gill apparatus and the intestines are most strongly exposed to the micro-plastic, however, laboratory studies of changes associated with exposure of the fibers is still insufficient to draw conclusions about the possible harmful effect.
Group led by David Hinton (David Hinton) from Duke University decided to fill this gap and conducted a series of experiments with Japanese medceu (Oryzias latipes) fish that spawn each day, which greatly simplifies the study of possible changes in the reproductive sphere. Twenty-seven pairs of adult fishes were randomly distributed in groups, a control group of nine pairs of fish were placed in aquariums with clean water. Two experimental groups, also with nine pairs of fish were in aquariums with a high content of fibers of polyester or polypropylene — the most common synthetic fibers.
In each aquarium of experimental groups were added 10 thousand fibers per liter of water, followed by addition of thousands of fibers of fish per day during water changes to account for the microfibers removed from the fecal mass. The average length of the polyester fibers in the experiment, 350 micrometers, of polypropylene — 380 micrometers.
The experiment lasted three weeks, during which researchers daily followed weight of the fish, the caviar production, consumption and absorption of microfibers — how many fibers have been received and how many are displayed. The results of the experiment showed that fibers did not lead to visible changes in the condition or body mass did not affect embryonic mortality, the development of eggs or hatching fry. After the experiment, the researchers examined the tissue of the fish to see what changes have occurred in the organs and tissues.
As expected, a large number of fibers contained in the water passes through the Gill cavity and the intestine and causes acute and chronic changes in the body of the fish. In particular, this has led to structural changes of the Gill plates increased the development of mucus in the gills and intestines, the formation of aneurysms in the vessels and changes in skin cells. Scientists stress that changes in the Gill apparatus can lead to a lack of oxygen making fish vulnerable to predators, less competitive in the production of food and in the struggle with other males for spawning.
The experiment showed that females who participated in the experiment, eventually began to produce more calves. Statistically significant results (p < 0.05) were obtained for the experimental group with the water-containing polypropylene, in the third week of exposure, the average number of eggs in this group amounted to 14 pieces, when in the control group in the third week of exposure was for 12 eggs, although within the group was not reached statistically significant values. The change in the number of eggs is a common biomarker of endocrine disruption in fish, which may indicate the effect of microfibers on endocrine function and reproductive system of the fish.
The researchers suggest that this is due to the chemicals that are added to the textile. This, for example, dyes or surfactants, used to remove static electricity from the fibers of synthetic fabric. To answer questions about the mechanisms of the influence of these chemical compounds to the fish, scientists will continue to study and will analyze the water samples and tissues obtained in this experiment.
Previously, scientists have examined the question of whether plastic in the body of the fish to be hazardous to humans. To see how well you do in this topic, you will substantial if you pass our test of”MicroProse”.