Mercury (Hg) is a globally ubiquitous pollutant that has received much attention due to its toxicity to humans and wildlife. The development of non-destructive sampling techniques is a critical step for sustainable monitoring of Hg accumulation. We evaluated the efficacy of non-destructive sampling techniques and assessed spatial, temporal, and demographic factors that influence Hg bioaccumulation in turtles. We collected muscle, blood, nail, and eggs from snapping turtles (Chelydra serpentina) inhabiting an Hg contaminated river. As predicted, all Hg tissue concentrations strongly and positively correlated with each other. Additionally, we validated our mathematical models against two additional Hg contaminated locations and found that tissue relationships developed from the validation sites did not significantly differ from those generated from the original sampling site. The models provided herein will be useful for a wide array of systems where biomonitoring of Hg in turtles needs to be accomplished in a conservation-minded fashion.

Studies were conducted on samples taken from giving birth women (n = 40) living in Poland, representing three age groups: 19–25, 26–30 and 31–38 years old. Mercury concentrations were measured with CV-AAS in placenta, umbilical cord, cord blood and amniotic fluid.The placentas weight did not exceed the 750 g value and was heavier than 310 g. Mean values of Hg concentrations in blood, placenta and umbilical cord were similar (c.a. 9 μg/g). High levels of mercury were noted in cord blood which in 75% of all observations exceeded (up to 17 μg/L) the safe dose set by US EPA (5.8 μg/L). No statistically significant differences in medium level of Hg in all the studied tissues among age groups of women were observed. Positive correlations between Hg concentrations in placenta and umbilical cord and cord blood were revealed as well as some negative ones between mercury concentrations and pregnancy parameters.

We determined the levels of prenatal Hg exposure in Wujiang City, located in the southeast of Taihu Lake in China's Jiangsu Province, and analyze the relationship between prenatal exposure to Hg and neonatal anthropometry, including birth weight, body length, and head circumference. From June 2009 to July 2010, a total of 213 mother-infant pairs were enrolled. The geometric means of Hg levels in maternal hair, fetal hair, placentas, and cord blood were 496.76 μg/kg, 233.94 μg/kg, 3.58 μg/kg, and 1.54 μg/L, respectively. The Hg levels detected in our study were significantly lower than those reported by previous studies. In addition, no significant correlations were found between Hg levels in maternal hair, fetal hair, placenta, or cord blood and neonatal anthropometrics. Together, our findings may be important for understanding the effects of prenatal exposure to Hg on newborns' development and have implications concerning the recommended dose for Hg.

Mercury (Hg) is a pervasive contaminant that can adversely affect predatory wildlife. Bird eggs provide insights into breeding females' Hg burdens, and are easily collected and archived. We present data on Hg trends in herring gull (Larus argentatus) eggs from five sites in Atlantic Canada from 1972 to 2008. We found a significant decrease in Hg at Manawagonish Island, New Brunswick and Île du Corossol, Quebec, but after correcting Hg for dietary shifts using stable isotopes (δ15N), these trends disappeared. Decreasing temporal trends of stable isotopes in gull eggs were observed at four sites, suggesting shifts in gull diets. At Gull Island, Newfoundland, diet-adjusted Hg increased from 1977 to 1992, dropped sharply between 1992 and 1996, and rose again from 1996 to 2008. After adjusting Hg trends for dietary shifts of herring gulls, it appears that environmental Hg in coastal ecosystems has remained relatively constant at most sites in Atlantic Canada over the last 36 years.

Many paddy fields have been contaminated by mercury (Hg) in mining areas of China. In this study, twenty-six rice cultivars and three Hg contaminated paddy fields in different geographic regions were selected for field trials and aimed to investigate the variations and similarities in total Hg (THg) and methylmercury (MeHg) accumulations in brown rice (seeds) across sites. Our results revealed widescale cultivar variation in THg (13–52 ng g−1 at Wanshan) and MeHg (3.5–23 ng g−1) accumulation and %MeHg (17.7–89%) in seeds. The ability to translocate is an important factor in the levels of THg and MeHg in seed. Cultivar tended to stability in THg accumulation across sites. Some cultivars accumulated lower concentrations of both THg and MeHg in seeds at fields seriously contaminated by Hg. Present results suggest that appropriate cultivar selection is a possible way to reduce THg and MeHg accumulation in seeds of rice grown in Hg-contaminated regions.

Several studies demonstrated high mercury (Hg) methylation and demethylation in the periphyton associated with floating roots in tropical ecosystems. The importance of aquatic plants on methylmercury production in three temperate ecosystems from south-western France was evaluated through Hg species concentrations, and Hg methylation/demethylation activities by using stable isotopic tracers (199Hg(II), Me201Hg). Hg accumulation and high methylation and demethylation yields were detected in plant roots and periphyton, whereas results for sediment and water were low to insignificant. The presence of sulfate reducing prokaryotes was detected in all compartments (T-RFLP based on dsrAB amplified through nested PCR) and their main role in Hg methylation could be demonstrated. In turn, sulfate reduction inhibition did not affect demethylation activities. The estimation of net MeHg budgets in these ecosystems suggested that aquatic rhizosphere is the principal location for methylmercury production and may represent an important source for the contamination of the aquatic food chain.

We have developed a local mass balance model for the St. Lawrence River near Cornwall, Ontario that describes the fate and transport of mercury in three forms, elemental, divalent, and methylated, in a five compartment environment (air, water, sediments, periphyton, and benthos). Our objective was to construct a steady-state mass balance model to determine the dominant sources and sinks of mercury in this environment. We compiled mercury concentrations, fluxes, and transformation rates from previous studies completed in this section of the river to develop the model. The inflow of mercury was the major source to this system, accounting for 0.42 mol month−1, or 95.5% of all mercury inputs, whereas outflow was 0.28 mol month−1, or 63.6% of all losses, and sediment deposition was 0.12 mol month−1, or 27.3% of all losses. Uncertainty estimates were greatest for advective fluxes in surface water, porewater, periphyton, and benthic invertebrates.

Little is known about effects of maternally transferred contaminants in snakes. The purpose of this study was to evaluate sublethal effects of maternally transferred mercury (Hg) on neonatal northern watersnakes (Nerodia sipedon). We captured 31 gravid females along a historically Hg-contaminated river. Following birth, we measured litter Hg concentrations and assessed locomotor performance, foraging ability (i.e., number of prey eaten, latency to first strike, strike efficiency, and handling time), and learning (i.e., change in foraging measures over time) in their offspring (n = 609). Mercury concentrations in offspring negatively correlated with motivation to feed and strike efficiency. Over time, strike efficiency and latency to strike decreased for all snakes in the study. However, offspring from contaminated areas maintained consistently lower efficiencies than reference individuals. This study is the first to examine sublethal behavioral effects of maternally transferred contaminants in snakes and suggests that maternally transferred Hg negatively affects offspring behavior.

Maternal transfer of mercury in fish represents a potential route of elimination for adult females and a risk to developing embryos. To better quantify maternal transfer, we measured Hg in female largemouth bass (Micropterus salmoides) muscle and eggs from six waterbodies. Mercury in eggs from two waterbodies exceeded a US federal screening level (0.3 μg g−1) and was likely high enough to cause adverse reproductive effects. We found a curvilinear relationship between female and egg Hg. Fish with <0.37 μg g−1 Hg had low levels of Hg in eggs; those with Hg >0.37 μg g−1 showed a direct relationship between egg and muscle Hg (Log10 egg Hg = −1.03 + 1.18 * log10 muscle tissue Hg + 2.15 * (log10 muscle tissue Hg + 0.35)2). We also report higher maternal transfer (0.2–13.2%) and higher ratios of egg to muscle tissue Hg (4–52%) and egg to whole body Hg concentrations (7–116%) than previously observed for teleost fish.

Maternal hair and blood were investigated as biomarkers for prenatal methylmercury (MeHg) exposure among seventeen mothers recruited at parturition in Wanshan, Guizhou Province, China, where rice ingestion was the primary MeHg exposure pathway and atmospheric mercury (Hg) levels were elevated. For all three trimesters (n = 51), hair total Hg (THg) and MeHg concentrations ranged from 0.27 to 4.9 μg/g (median: 0.96 μg/g) and 0.077 to 2.3 μg/g (median: 0.43 μg/g), respectively, while blood THg levels ranged from 1.7 to 11 μg/L (median: 3.0 μg/L, n = 17). Despite adequate hair washing procedures, median %MeHg (of THg) was 37% (range: 14–89%, n = 51), indicating exogenous inorganic Hg(II) contamination or incorporation of elemental Hg (Hgo) into the hair shaft were important. Rice MeHg levels (n = 17) were highly correlated with blood THg (r2 = 0.66) compared to hair MeHg (r2 = 0.31) (when variables were log10-transformed), suggesting blood THg was a more preferable biomarker for prenatal MeHg exposure within this population.