Western reef heron (Egretta gularis) as a bio-indicator of mercury pollution in the Hara International Wetland, Persian Gulf

Mercury and organic compounds are the most toxic substances for aquatic ecosystems. In the this study, feasibility using of western reef heron feathers as bio-indicator of mercury contamination in the Hara International Wetland. Accumulation of mercury were investigated in body and wing feathers in this species. Furthermore, we evaluated factors influencing mercury levels such as sex and morphometric parameter in the mentioned species. The analyses were carried out using advanced mercury analyzer (AMA 254) according to EPA 7473 method. There were no significant differences between body and wing feathers in Hg concentration in this bird (P>0.05). Results showed that morphmetric parameters such as weight, length and wing length and also sex have no significant effects on total Hg accumulation in this bird. Mercury levels in feather were below the threshold of 5–15mg kg–1 that may affect birds. Results also showed the low bioaccumulation of Hg in the Hara Wetland ecosystem is not so critical. Accordingly, we recommend that the western reef heron can use as a biomonitoring of mercury pollution in this region.