Tracking Down an Unusual Source of Mercury Enrichment in Fish from Saipan Lagoon, Saipan, Commonwealth of the Northern Mariana Islands
In 2004-2005, several species of fish were collected for mercury analysis from Saipan Lagoon. The highest overall levels, while not excessive, were found in representatives collected from Hafa Adai Beach, located some distance from known sources of mercury contamination. A follow-up investigation, aimed at identifying land-based sources of mercury in this particular area, was launched in 2007. To this end, sediment and soil samples were respectively collected from the beach and all potential drainage pathways to the coast. Bivalve mollusks and two types of fish with limited foraging ranges were also collected from the focus area and from other sites to the north and south. Marginally elevated mercury levels were detected in sediments at the mouth of a storm drain at the southern end of Hafa Adai Beach and prompted additional soil sampling further inland along a drainage canal. Mercury concentrations in these samples generally increased from around 30 ng/g (parts per billion dry weight) at the mouth of the storm drain to approximately 200 ng/g at the Middle Road entrance to Saipans only public hospital, about 1 km away. Additional soil sampling along a small drainage ditch within the hospital grounds revealed mercury levels in excess of 1000 ng/g a few meters down gradient of an old incinerator site. The incinerator was operated by the hospital for approximately 20 years before it was finally dismantled in early 2006. Bivalves collected from the intertidal zone and nearshore waters down gradient of the impacted storm drain contained mercury levels that were unremarkable. Fish captured from nearshore seagrass beds in the same area and from coral patch reefs further offshore generally revealed lower mercury levels than their counterparts sampled three years earlier. Marine sediments taken from each of these habitats yield mercury values within normal ranges. The implications of the data are discussed both from an environmental and human health perspective.
DENTON Gary R.W. TRIANNI Michael S. BEARDEN Brian G. HOUK Peter C. STARMER John A.
Water and Environmental Research Institute of the Western Pacific, UOG Station, University of Guam, Saipan Department of Lands and Natural Resources, Division of Fish and Wildlife, PO Box 10007, Saipa Saipan Division of Environmental Quality, PO Box 501304, Saipan MP 96950, USA Pacific Marine Resources Institute, PMB 1156 PO Box 10003, Saipan, MP 96950, USA
国际会议
2011 International Symposium on Environmental Science and Technology(2011 环境科学与技术国际会议 2011 ISEST)
广东东莞
英文
127-137
2011-06-01（万方平台首次上网日期，不代表论文的发表时间）