Survey of contamination of estrogenic chemicals in Japanese and Korean coastal waters using the wild grey mullet (Mugil cephalus)

Abstract

We monitored the contamination by environmental estrogens (EEs) of coastal areas in Korea and Japan using the wild grey mullet. The grey mullet were collected from Ansan, Jeju, Yeosu, Tongyeong, and Busan in Korea and Nagasaki, Omuta, and Fukuoka in Japan.Contamination by EEs was determined by measuring vitellogenin (VTG) levels in serum and identifying gonadal abnormalities histologically (i.e., testis-ova). In four sites in Korea (Ansan, Yeosu, Tongyeong, and Busan) and two sites in Japan (Nagasaki and Fukuoka), serum VTG in immature and male grey mullet was detected at levels greater than 1.0 g/ml, which is considered to be an abnormal level. Although, testis-ova were observed in some individuals collected in Ansan, Tongyeong, and Busan in Korea and Omuta in Japan, there was no correlation between individuals with testis-ova and individuals with abnormal levels of VTG. Furthermore, in Japan, serum VTG levels of fish collected from Nagasaki and Fukuoka was also greater than 1.0 g/ml. Although individuals with testis-ova were found in Omuta, these fish expressed normal levels of serum VTG. Our results suggest that the grey mullet living in these coastal areas are influenced by EEs in the environment. Furthermore, it appears that the production of VTG and the occurrence of testis-ova are caused by different mechanisms.

Gene Structure and Estrogen-Responsive mRNA Expression of a Novel Choriogenin H Isoform from a Marine Medaka Oryzias dancena

“…Coastal or marine environments are often defined as the "final destination" for pollutants that arise from land-based anthropogenic and industrial activities, and this means that the living organisms that inhabit coastal areas are often chronically exposed to various pollutants (Koh et al, 2005;Aoki et al, 2010). Among these pollutants, xenoestrogens are potent endocrine-disrupting chemicals (EDCs) that deregulate gene expression and enzymatic functions associated with the reproduction of the exposed organisms (Rotchell and Ostrander, 2003;Tokumoto et al, 2004Tokumoto et al, , 2011.…”

Enzyme-linked immunosorbent assay (ELISA) measurement of vitellogenin in plasma and liver histopathology in barfin plaice Liopsetta pinnifasciata from Amursky Bay, Sea of Japan

“…The abundance of Vg in fish may induce, in addition to intersex, different pathological changes in internal organs, including hepatocyte hypertrophy, disruption of spermatogenesis, vacuolation of the testis and obstruction or rupture of renal glomeruli (Folmar et al 2001;Zaroogian et al 2001;Bjerregaard et al 2006). Numerous studies have been devoted to the detection of vitellogenin in wild and experimental fish, and a few papers have examined the correlation between plasma Vg level and gonad or liver pathologies in experimentally treated fish (Janssen et al 1997;Folmar et al 2001;Zaroogian et al 2001), but the interdependence between liver and gonad pathology and Vg concentration in the plasma of wild fish has not been widely studied (Bjerregaard et al 2006;Aoki et al 2010). …”

Vitellogenesis and choriogenesis in fishes

“…Until now, the investigation targeting both species of Mugilidae detected extremely high estrogen activity in urban coastal waters, and histopathological observations revealed some fish to have abnormal gonads, including ovotestes. However, the connection between blood Vtg levels and these reproductive abnormalities has not yet been confirmed [120].…”