The first observation of ingesting microplastic particles in wader on the southern shores of the Caspian Sea: Common Teal (Anas crecca)

The birds have always been of great importance in various cycles of ecosystems. In between the number of microplastics in marine environments is increasing. In recent years, due to the entry of marine debris into the environment, all kinds of particles such as fiber, fragment, film and other particles in different sizes are accidentally ingested instead of food or accidentally by birds. Due to their indigestion, these particles block the gastrointestinal tract, reduce the useful volume of the gastrointestinal tract, suffocate and in some cases lead to the death of the animal. The present study is the first to investigate microplastic observations in the Anas crecca waterfowl of the southern Caspian Sea basin. The abundance, type, size, shape and color of microplastics in the stomach contents of this bird were examined.

Carcasses discovered from hunters in the northern provinces and lost specimens from the coast were described. SZM-LED2 Stereomicroscope with objective lens of 0.7, 0.8, 1, 1.5, 2, 3, 4, 4.5 and eye piece 10x was used to detect microplastic particles by OptikaView software version 7.

The results show that in the two provinces of Guilan and Mazandaran, a total of 316 microplastic particles including fiber, fragment and film were found in 46 of common teal (Anas crecca), which: fiber and then fragment had the highest frequency. The size range of the parts varied from the film with 0.071 mm to fiber with 13.543 mm. Also, the greatest variety of shapes was related to long linear fiber components.

The relationship between fiber density and residential areas can be considered as an indicator of urban ecosystem pressure. Continuous monitoring of the environment with the help of microplastics in the areas where bird colonies are found should be considered.