Using histopathological changes as a biomarker to trace contamination loading of Musa Creeks (Persian Gulf)

Gill histological changes were used as a biomarker to evaluate the health of yellowfin seabream, Acanthopagrus latus (A. latus), collected from different sites in Musa Creeks including: (A) Petrochemical, (B) Jaafari, (C) Ghazaleh, (D) Majidieh, and (E) Zangi creeks. Also Genaveh with relatively clean water was selected as reference. The gills of 60 A. latus were fixed in Bouin's solution for 12 hr, dehydrated in a graded series of ethanol, and embedded in paraffin. Five micrometer thick sections were stained in H&E and Periodic Acid Schiff for microscopic examination. Also, the presence of gill histological alterations was assessed by the histopathologic alteration index (HAI). The gill morphological abnormalities include mucus secretion increase, debris, blood plaque, and shortening of filaments. The gill pathological changes included lamellar cells hyperplasia, aneurysm, lamellar fusion, and epithelial lifting. The HAI means were varied from moderate to severe in sites A and B, thus these sites are considered as being of low quality. Some severe pathological alterations were observed in site D, but their distribution was lower than sites A and B. The least HAI means of sites C and E demonstrated their good environmental quality. The results suggest that there is close relation between amounts of pathological alterations and environmental contamination.