Steroid Fingerprint Analysis of Endangered Caspian Seal (Pusa caspica) through the Gorgan Bay (Caspian Sea)

Abstract

The profile of steroid congeners was evaluated in Caspian seals Pusa caspica by age, sex, and tissue-specific bioaccumulation, and compared with that of abiotic matrices (seawater, surface sediment, and suspended particulate materials, SPMs) from Miankaleh Wildlife/Gorgan Bay, (Caspian Sea, Iran). To identify the level of human fecal contamination, ∑25 sterol congeners were measured in all abiotic/biotic samples, revealing coprostanol, a proxy for human feces, as the most abundant sterol (seawater: 45.1–20.3 ng L–1; surface sediment: 90.2–70.3 ng g–1 dw; SPMs: 187.7–157.6 ng g–1 dw). The quantification of ∑25 sterols in seals followed the order of brain > liver > kidney > heart > blood > spleen > muscle > intestine > blubber > fur, and in both sexes coprostanol level (8.95–21.01% of ∑25s) was higher in blubber and fur, followed by cholesterol in brain, liver, kidney, heart, and blood, cholestanone in intestine and muscle, and β-sitosterol in spleen. Though no age/sex differentiation was observed, the mean concentration of ∑25s was higher in male than females and pup. Different diagnostic ratios revealed sterols originating from human and nonhuman sewage sources. Findings pinpoint the urgent necessity to investigate the ecotoxicity of fecal sterols in mammals, and consequent implications for human health.

Occurrence and source of PAHs in Miankaleh International Wetland in Iran

“…Miankaleh International Wetland (Coastal Biosphere Reserve) has been recognized as a "Ramsar site" since 1975 because of its cultural inheritance, historical, biological and esthetic characteristics (Gholami et al, 2020;Alipour et al, 2015). Miankaleh Wetland is a protected region, located on the southeast part of the Caspian Sea (Iran), a rich ecosystem and ecological haven in Asia (Ranjbar Jafarabadi et al, 2020). This wetland is the most significant wintering area for waterbirds in Caspian Sea region (Alipour et al, 2015), which is an internationally recognized sanctuary for migratory birds (Gholami et al, 2020;Sinkakarimi et al, 2018).…”

“…1). This wetland has both an aquatic ecosystem of Gorgan Bay (semi enclosed and brackish) with an area of about 44800 ha (Ranjbar Jafarabadi et al, 2020), and a land ecosystem with a relatively narrow strip called Miankaleh Peninsula with an area of about 24000 ha. Miankaleh Peninsula separates the Miankaleh Wetland (with a maximum depth of about 6.5 m and a mean depth of about 1.8 m) from the Caspian Sea (Mansoori, 2009) which increases from west to east, with a clockwise direction of flow.…”