Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

Event Name/Location

2008 Ocean Sciences Meeting, Orlando, FL, March 2-7, 2008

Document Type

Conference Proceeding

Publication Date



The Alvarado Lagoon System (ALS) consists of shallow rivers and lagoons connected to the Gulf of Mexico (GOMEX) by a narrow channel. We collected samples of water and seafood in the wet (September 2005) and dry (March 2003 and 2005) seasons, and human hair and sediment in 2005. Total Hg in sediments ranged from 27.5 to 90.5 μg Hg/g dry weight, while fish and shellfish Hg levels ranged from 0.01 to 0.35 μg Hg/g wet weight. Total Hg in human hair ranged from 0.10 to 3.36 μg Hg/g (n = 47) and 58 % of the hair samples were above 1.00 μg Hg/g. Mean hair Hg levels were 1.12 ± 0.62 and 1.48 ± 0.86 μg/g for children (n = 20) and adults (n = 27), respectively. Water column concentrations of total unfiltered Hg ranged from 0.9 to 12.6 ng/L. These levels are similar to other estuaries that discharge into the northern GOMEX. The ALS discharges around 95 kg Hg/yr into GOMEX, approximately 0.38 % of the total annual atmospheric Hg deposition, and about 0.43 % of annual Mississippi river discharge.