Brenda M. Sanders

Free Cupric Ion Activity in Seawater: Effects on Metallothionein and Growth in Crab Larvae

Crab zoeae (Rhithropanopeus harrisii) were exposed during their development opment to a range of free cupric ion activities regulated in seawater by use of a copper chelate buffer system. Most cytosolic copper was found to be associated with metallothionein. Copper-thionein could be related to free cupric ion activity, and a shift in copper-thionein accumulation was correlated with inhibition of larval growth. These data reveal predictable relations between cupric ion activity in seawater and processes at the cellular and organismic levels.

RELATIONSHIPS BETWEEN FREE CUPRIC ION CONCENTRATIONS IN SEA WATER AND COPPER METABOLISM AND GROWTH IN CRAB LARVAE

Crab larvae (Rhithropanopeus harrisiiere exposed to a range of free cupric ion concentrations, [Cu2+], regulated in sea water by a metal chelate buffer system. We found a biphasic relationship between intracellular copper distribution and [Cu2+] in sea water. At [Cu2+] within the ambient range (10-12.4 to 10-10.6 M), cytosolic copper was associated with both metallothionein (MT) and high molecular weight (HMW) ligands, and was independent of external [Cu2+]. At higher [Cu2+], copper was also associated with very low molecular weight (VLMW) ligands, and accumulated in this ligand pool and the MT pool as external [Cu2+] increased. In marked contrast, copper in the HMW ligand pool did not correlate with [Cu2+] in sea water over the entire range of exposures. Reductions in larval growth occurred at greater than estimated ambient [Cu2+] and correlated with copper accumulation in the MT and VLMW pools.

Coordinating ecological risk assessment with natural resource damage assessment: A panel discussion

Contaminated sites in the United States undergo remediation and restoration through regulatory programs that lead the 2 processes through independent but often parallel pathways with different objectives. The objective of remediation is to reduce risk to human health and the environment, whereas that of restoration is to restore injured resources and compensate the public for lost use of the services that natural resources provide. More complex sites, such as those associated with large river systems and urban waterways, have resulted in increasingly larger-scale ecological risk assessments (ERAs) and natural resource damage assessments (NRDAs) that take many years and involve diverse practitioners including scientists, economists, and engineers. Substantial levels of effort are now frequently required, creating a need for more efficient and cost-effective approaches to data collection, analyses, and assessments. Because there are commonalities in the data needs between ERAs and NRDAs, coordination of the design and implementation of site-specific studies that meet the needs of both programs could result in increased efficiency and lower costs. The Association for Environmental Health and Sciences Foundation convened a panel of environmental practitioners from industry, consulting, and regulatory bodies to examine the benefits and challenges associated with coordinating ERA and NRDA activities in the context of a broad range of regulatory programs. This brief communication presents the opinions and conclusions of the panelists on these issues and reports 2 case studies for which coordinated ERA and NRDA activities produced a positive outcome. Integr Environ Assess Manag 2016;12:616-621.