Food Supply and Seawater pCO2 Impact Calcification and Internal Shell Dissolution in the Blue Mussel Mytilus edulis

Progressive ocean acidification due to anthropogenic CO2 emissions will alter marine ecosytem processes. Calcifying organisms might be particularly vulnerable to these alterations in the speciation of the marine carbonate system. While previous research efforts have mainly focused on external dissolution of shells in seawater under saturated with respect to calcium carbonate, the internal shell interface might be more vulnerable to acidification. In the case of the blue mussel Mytilus edulis, high body fluid pCO2 causes low pH and low carbonate concentrations in the extrapallial fluid, which is in direct contact with the inner shell surface. In order to test whether elevated seawater pCO2 impacts calcification and inner shell surface integrity we exposed Baltic M. edulis to four different seawater pCO2 (39, 142, 240, 405 Pa) and two food algae (310–350 cells mL−1 vs. 1600–2000 cells mL−1) concentrations for a period of seven weeks during winter (5°C). We found that low food algae concentrations and high pCO2 values each significantly decreased shell length growth. Internal shell surface corrosion of nacreous ( = aragonite) layers was documented via stereomicroscopy and SEM at the two highest pCO2 treatments in the high food group, while it was found in all treatments in the low food group. Both factors, food and pCO2, significantly influenced the magnitude of inner shell surface dissolution. Our findings illustrate for the first time that integrity of inner shell surfaces is tightly coupled to the animals' energy budget under conditions of CO2 stress. It is likely that under food limited conditions, energy is allocated to more vital processes (e.g. somatic mass maintenance) instead of shell conservation. It is evident from our results that mussels exert significant biological control over the structural integrity of their inner shell surfaces

Frank Leslie's Sunday magazine.

Editor: v. 10- Thomas DeWitt Talmadge.From Nov. 1883 to June 1889 cover-titles read: Frank Leslie's illustrated Sunday magazine: a journal of refined userful and interesting literature.Vol. 9 (Jan. - June 1881) has title: The Sunday magazine. This title is continued on covers through Nov. 1881.Title from caption.Includes music.Mode of access: Internet

Preliminary screening of contaminants in the off-site surface water environment downstream of the US Department of Energy Oak Ridge Reservation. Environmental Restoration Program

Previously reported concentrations of radionuclides and of inorganic and organic compounds in the surface water environment off-site of the US Department of Energy/Oak Ridge Reservation (DOE/ORR) suggest the presence of a large number of substances of possible concern to the protection of human health and the ecosystem. Screening of these data, as part of the initial scoping phase of the Clinch River Resource Conservation and Recovery Act Facility Investigation, is necessary to develop a field sampling plan for the acquisition of additional data through the identification of potential contaminants of concern for further evaluation and investigation. The results of this report are based on human health risk end points. For the purposes of screening, conservative and nonconservative estimates of potential maximum exposures were used to identify, respectively, definitely low- and definitely high-priority pollutants. Because of relatively high concentrations of contaminants in sediment, the presence of industrial and agricultural wastes not related to DOE/ORR operations, and the use of a lifetime risk for carcinogens of 10{sup {minus}6} as a lower screening criterion, no surface water reach considered in this study was identified as low priority. In contrast to this result, three contaminants, arsenic in water and thallium in fish of McCoy Branch and {sup 137}Cs in the sediment of the White Oak Creek embayment downstream from White Oak Lake, were tentatively identified as definitely high-priority substances. These locations are within the boundaries of ORR. Nonconservative estimates of exposure identified arsenic, antimony, thallium, uranium, polychlorinated biphenyls 1254 and 1260, chlordane, {sup 60}Co, and {sup 234}Pa as potentially high-priority contaminants in at least one or more locations. These are the contaminants that should receive the most scrutiny in future investigations

Preliminary screening of contaminants in the off-site surface water environment downstream of the US Department of Energy Oak Ridge Reservation

Previously reported concentrations of radionuclides and of inorganic and organic compounds in the surface water environment off-site of the US Department of Energy/Oak Ridge Reservation (DOE/ORR) suggest the presence of a large number of substances of possible concern to the protection of human health and the ecosystem. Screening of these data, as part of the initial scoping phase of the Clinch River Resource Conservation and Recovery Act Facility Investigation, is necessary to develop a field sampling plan for the acquisition of additional data through the identification of potential contaminants of concern for further evaluation and investigation. The results of this report are based on human health risk end points. For the purposes of screening, conservative and nonconservative estimates of potential maximum exposures were used to identify, respectively, definitely low- and definitely high-priority pollutants. Because of relatively high concentrations of contaminants in sediment, the presence of industrial and agricultural wastes not related to DOE/ORR operations, and the use of a lifetime risk for carcinogens of 10{sup {minus}6} as a lower screening criterion, no surface water reach considered in this study was identified as low priority. In contrast to this result, three contaminants, arsenic in water and thallium in fish of McCoy Branch and {sup 137}Cs in the sediment of the White Oak Creek embayment downstream from White Oak Lake, were tentatively identified as definitely high-priority substances. These locations are within the boundaries of ORR. Nonconservative estimates of exposure identified arsenic, antimony, thallium, uranium, polychlorinated biphenyls 1254 and 1260, chlordane, {sup 60}Co, and {sup 234}Pa as potentially high-priority contaminants in at least one or more locations. These are the contaminants that should receive the most scrutiny in future investigations