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New Hampshire Department of Environmental Services

Media Center

DATE: February 25, 2019
Kirsten Nelson, NHDES Watershed Management Bureau, 603-271-1152

Mapper Now Includes Mercury in Fish Tissue Data

CONCORD, NH - The New Hampshire Department of Environmental Services (NHDES) has updated its interactive surface water quality map, the New Hampshire Lake Information Mapper. In addition to providing links to historical and current lake trophic survey reports, current volunteer lake assessment program reports, exotic aquatic species distribution information and other reports, the Mapper now includes reports for individual lakes and ponds with mercury in fish tissue data. Two hundred twenty-seven lakes and ponds have waterbody-specific mercury in fish tissue data. Nearly 2,000 reports covering greater than 1,000 waterbodies from 1975 to 2018 are available through this map.

Mercury is a naturally occurring element that enters the atmosphere by burning fossil fuels, trash and medical waste. Once deposited on the landscape, some portion is biologically transformed into a highly toxic form known as methyl-mercury. Methyl-mercury occurs in low concentrations in surface waters; however, it moves up the food chain and can result in high concentrations in fish consumed by humans and wildlife. Small concentrations of mercury can cause brain damage, which is why in New Hampshire, a statewide fish consumption advisory has been in place since 1994, with revisions in 2001 and 2008. A new NHDES report on mercury in fish tissue of New Hampshire lakes is available here: Adobe Acrobat Reader Symbol

NHDES has analyzed fish tissue for mercury concentration since 1992. Fish are collected by NHDES, NH Fish and Game, or interested citizens.  This is a free public service, and interested citizens are encouraged to participate. Information on how to submit fish for mercury testing is available here: Adobe Acrobat Reader Symbol

To access the Lake Information Mapper, please visit:



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