We measured mercury (Hg) isotope ratios in sediments and various estuarine organisms (green crab,... more We measured mercury (Hg) isotope ratios in sediments and various estuarine organisms (green crab, blue mussel, killifish, eider) to investigate methylmercury (MMHg) sources and exposure pathways in five Northeast coast (U.S.) estuaries. The mass independent Hg isotopic compositions (MIF; Δ(199)Hg) of the sediments were linearly correlated with the sediment 1/Hg concentrations (Δ(199)Hg: r(2) = 0.77, p < 0.05), but the mass dependent isotope compositions (MDF; δ(202)Hg) were not (r(2) = 0.26, p = 0.16), reflecting inputs of anthropogenic Hg sources with varying δ(202)Hg. The estuarine organisms all display positive Δ(199)Hg values (0.21 to 0.98 ‰) indicating that MMHg is photodegraded to varying degrees (5-12%) prior to entry into the food web. The δ(202)Hg and Δ(199)Hg values of most organisms can be explained by a mixture of MMHg and inorganic Hg from sediments. At one contaminated site mussels have anomalously high δ(202)Hg, indicating exposure to a second pool of MMHg, compare...
In North America and Europe, sea ducks are important indicators of ecological health and inshore ... more In North America and Europe, sea ducks are important indicators of ecological health and inshore marine pollution. To explore spatial variation in mercury accumulation in common eiders in the northeastern United States, we compared concentrations of total mercury in common eider blood at several New England locations between 1998 and 2013. Eider food items (mollusks) were collected and analyzed to determine if mercury concentrations in eider blood were indicative of local mercury bioavailability. Eiders from Plum Island Sound, MA had a significantly higher mean blood mercury concentration (0.83 μg/g) than those in other locations. Mean mercury levels in this population were also nearly three times higher than any blood mercury concentrations reported for common eiders in published literature. We observed consistent patterns in eider blood mercury and blue mussel mercury concentrations between sites, suggesting a tentative predictive quality between the two species.
In the fall of 2013, Biodiversity Research Institute (Gorham, ME, USA) partnered with Sustenta So... more In the fall of 2013, Biodiversity Research Institute (Gorham, ME, USA) partnered with Sustenta Soluciones S.A. de C.V. (México City, México) to conduct a three-week pilot environmental study along a 200-km stretch of coastline in the State of Guerrero. The focus was on three common pollutants often used as reliable predictors of ecological toxicity: plastics, mercury, and petroleum (PAHs). The pilot was a component of a much larger conservation campaign called Limpia Guerrero 2013 funded by the State of Guerrero. Marine Plastics Pollution. Beach debris abundance was estimated from one-meter-wide belt surveys along 100-m stretches of beach on seven beaches between Acapulco to Zihuatenejo/Ixtapa, sorted and categorized by 10 types, and weighed. Nearly 9,700 pieces of litter were collected from a total sample area of 1.5 hectares. Litter density varied from 0.42 to 44.26 pieces per m2. As a category of debris, plastics pollution varied from 0.05 to 4.44 pieces per m2 of beach. The aver...
We measured mercury (Hg) isotope ratios in sediments and various estuarine organisms (green crab,... more We measured mercury (Hg) isotope ratios in sediments and various estuarine organisms (green crab, blue mussel, killifish, eider) to investigate methylmercury (MMHg) sources and exposure pathways in five Northeast coast (U.S.) estuaries. The mass independent Hg isotopic compositions (MIF; Δ(199)Hg) of the sediments were linearly correlated with the sediment 1/Hg concentrations (Δ(199)Hg: r(2) = 0.77, p < 0.05), but the mass dependent isotope compositions (MDF; δ(202)Hg) were not (r(2) = 0.26, p = 0.16), reflecting inputs of anthropogenic Hg sources with varying δ(202)Hg. The estuarine organisms all display positive Δ(199)Hg values (0.21 to 0.98 ‰) indicating that MMHg is photodegraded to varying degrees (5-12%) prior to entry into the food web. The δ(202)Hg and Δ(199)Hg values of most organisms can be explained by a mixture of MMHg and inorganic Hg from sediments. At one contaminated site mussels have anomalously high δ(202)Hg, indicating exposure to a second pool of MMHg, compare...
In North America and Europe, sea ducks are important indicators of ecological health and inshore ... more In North America and Europe, sea ducks are important indicators of ecological health and inshore marine pollution. To explore spatial variation in mercury accumulation in common eiders in the northeastern United States, we compared concentrations of total mercury in common eider blood at several New England locations between 1998 and 2013. Eider food items (mollusks) were collected and analyzed to determine if mercury concentrations in eider blood were indicative of local mercury bioavailability. Eiders from Plum Island Sound, MA had a significantly higher mean blood mercury concentration (0.83 μg/g) than those in other locations. Mean mercury levels in this population were also nearly three times higher than any blood mercury concentrations reported for common eiders in published literature. We observed consistent patterns in eider blood mercury and blue mussel mercury concentrations between sites, suggesting a tentative predictive quality between the two species.
In the fall of 2013, Biodiversity Research Institute (Gorham, ME, USA) partnered with Sustenta So... more In the fall of 2013, Biodiversity Research Institute (Gorham, ME, USA) partnered with Sustenta Soluciones S.A. de C.V. (México City, México) to conduct a three-week pilot environmental study along a 200-km stretch of coastline in the State of Guerrero. The focus was on three common pollutants often used as reliable predictors of ecological toxicity: plastics, mercury, and petroleum (PAHs). The pilot was a component of a much larger conservation campaign called Limpia Guerrero 2013 funded by the State of Guerrero. Marine Plastics Pollution. Beach debris abundance was estimated from one-meter-wide belt surveys along 100-m stretches of beach on seven beaches between Acapulco to Zihuatenejo/Ixtapa, sorted and categorized by 10 types, and weighed. Nearly 9,700 pieces of litter were collected from a total sample area of 1.5 hectares. Litter density varied from 0.42 to 44.26 pieces per m2. As a category of debris, plastics pollution varied from 0.05 to 4.44 pieces per m2 of beach. The aver...
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