Histopathological characterization of transient and nestling birds affected by the 2020 spill of diesel fuel in the Russian Arctic

Abstract

Abstract Environmental pollution caused by spills of petroleum oil and its products poses a hazard to the health of wild birds. The purpose of the present study was to investigate morphological changes in the transient and nestling birds inhabiting the area affected by the spill of diesel fuel. Two groups of birds were studied: 1 – transient birds (Anas acuta and Mareca penelope); 2 – nestling birds (Aythya fuligula L. and Mergus serrator L.), which inhabit this ecotope. These species are all Anseriformes of the Anatidae family. Birds were caught along the Ambarnaya River in July and August 2022. Birds were captured, organs were removed (liver, lungs and heart) and examined using histological methods. Organ sections were stained with Hematoxylin & Eosin in automatic mode (AFOMK-16-26, Russia). The specimens were examined and scored under light microscope and with digital camera (Carl Zeiss, Germany). Histology of organs and tissues of breeding and migratory birds did not reveal any significant differences between the two groups. More pronounced pathologies were observed in breeding birds. All species had brown foreign particles distributed in blood and showed destructive changes in organs and tissues leading to pronounced dysfunction of the organs. In some bird species, neoplastic processes were observed.