Microplastic damages the gills of fish and increases the amount of caviar in them. This conclusion was made by scientists from Duke University, a study of which was published in the journal PLoS One.
Humanity produces a huge amount of plastic – in 2015 this figure was 400 million tons per year, and by 2025 production will double. According to scientists, every year, 8 million tons of plastic waste are delivered to the ocean. However, the authors of the study note that this amount may turn out to be only 1% of the actual annual pollution.
Biologists have already proven that microscopic particles, into which plastic breaks up, harm marine life – many animals and plants take them for food, and then die or suffer from various diseases.
Microplastic has been found in every marine mammal studied in a recent study in the UK. In 2017, it turned out that plastic particles are found in tap water around the world – they are consumed by residents of Europe, Japan and Russia.
In a new study, researchers studied the effect of microplastics on fish. Scientists have conducted a series of experiments on Japanese honey (Oryzias latipes). This is a species that spawns daily – this greatly simplifies the study of the effect of microplastics on its reproductive functions.
27 pairs of fish were divided into several groups – two of them were kept in aquariums with a high number of microscopic particles of polyester in water, and two more groups were in aquariums with clean water.
Researchers added 1,000 fibers per liter of water daily to each aquarium of the experimental group, taking into account particles removed with fecal masses. Three weeks later, scientists found that microplastic fibers caused acute changes in the gills and intestines in fish from the experimental group. This probably reduced oxygen supply and made the fish less protected against predators.
In addition, the number of eggs secreted by females sharply increased. This means that microfibers negatively affected the endocrine and reproductive systems of fish.