Assessment of Sediment Contamination in Casco Bay

EXECUTIVE SUMMARY Contaminant concentrations of sediment samples collected approximately 10 years apart are compared in an attempt to establish current status of contaminant concentrations in Casco Bay, to determine whether contaminant concentrations are increasing, decreasing or remain unchanged, and to examine any changes in the geographical distribution of contaminants. This process is complicated by the potential of re-suspension of older sediment back to the surface, the non-homogeneity of sediments, low concentrations for some analytes and variability of different analytical methods. In spite of these complications several trends are observed. As expected, most of the contaminants appear to be decreasing in concentrations. Total PAH concentrations in the sediment are an exception. When comparing total PAH concentration in 1991 and 2001, there is neither an increase nor a decrease when the analytical uncertainties are considered. The continuing increased use of fossil fuels that may add additional PAH to the sediments appears to be balanced by increasing controls that lower PAH inputs. Total pesticides as well as 4,4-DDE, 4,4-DDD and total DDTs indicate a decrease from 1991 to 2000/2001. Total PCB concentrations also suggest a decrease over this time period. Silver is the only trace element increasing in concentration at most sampling sites from 1991 to 2001. The reason for this difference is not clear. Concentrations decreased at the majority of the sampling sites for cadmium, chromium, mercury, nickel, and selenium with no apparent difference for arsenic, copper lead and zinc. Tributyltin and total butyltin concentrations decreased over the time period from 1994 to 2000/2001. The overall indication for dioxin/furans is no change between sampling periods. The planar PCB indicates no change (PCB 77) or decreasing concentrations (PCB 126). With the many complicating factors, the interpretation of these data needs to be done with care. There is no indication from these data that any of the contaminants measured has increased by more than a factor of 2. At most Casco Bay sites and for most analytes there is either no change or a decrease. There are sites where increases are apparent and many of these sites are at the shallow water sites or at the Inner Bay sites where concentrations are higher and new inputs are more likely Sediments from the Inner Bay region of Casco Bay; closest to Portland, ME; contain the highest levels of trace metals, PCBs, DDTs, and chlordane. For contaminants other than PAH (and these only at a few locations) and PCBs at one location, the levels of contamination in Casco Bay would not be considered high on a national basis, based on Macauley et al. (1994). The geographical distribution of most contaminants remains similar to those determined in 1991/1994. There are generally higher contaminant concentrations in the vicinity of Portland and other populated and industrial areas. Toxicity tests for selected sites and comparison of 2 contamination concentrations to ERL or ERM indicate the sediments are not toxic. The overall conclusion based on the available data is that the contaminant loading for Casco Bay, as a whole, is decreasing or remaining the same and these concentrations are not likely to adversely affect the biota. The geographic distribution of sediment contaminants is generally confirmed in the analysis of mussel tissue by the Casco Bay Estuary Project and the Maine Department of Environmental Protection (DEP) (Doggett, DEP, personal communication)

Survey of sediment quality in Sabine Lake, Texas and vicinity

The toxicity of sediments in Sabine Lake, Texas, and adjoining Intracoastal Waterway canals was determined as part of bioeffects assessment studies managed by NOAA’s National Status and Trends Program. The objectives of the survey were to determine: (1) the incidence and degree of toxicity of sediments throughout the study area; (2) the spatial patterns (or gradients) in chemical contamination and toxicity, if any, throughout the study area; (3) the spatial extent of chemical contamination and toxicity; and (4) the statistical relationships between measures of toxicity and concentrations of chemicals in the sediments. Surficial sediment samples were collected during August, 1995 from 66 randomly-chosen locations. Laboratory toxicity tests were performed as indicators of potential ecotoxicological effects in sediments. A battery of tests was performed to generate information from different phases (components) of the sediments. Tests were selected to represent a range in toxicological endpoints from acute to chronic sublethal responses. Toxicological tests were conducted to measure: reduced survival of adult amphipods exposed to solid-phase sediments; impaired fertilization success and abnormal morphological development in gametes and embryos, respectively, of sea urchins exposed to pore waters; reduced metabolic activity of a marine bioluminescent bacteria exposed to organic solvent extracts; and induction of a cytochrome P-450 reporter gene system in exposures to solvent extracts of the sediments. Chemical analyses were performed on portions of each sample to quantify the concentrations of trace metals, polynuclear aromatic hydrocarbons, and chlorinated organic compounds. Correlation analyses were conducted to determine the relationships between measures of toxicity and concentrations of potentially toxic substances in the samples. Based upon the compilation of results from chemical analyses and toxicity tests, the quality of sediments in Sabine Lake and vicinity did not appear to be severely degraded. Chemical concentrations rarely exceeded effects-based numerical guidelines, suggesting that toxicant-induced effects would not be expected in most areas. None of the samples was highly toxic in acute amphipod survival tests and a minority (23%) of samples were highly toxic in sublethal urchin fertilization tests. Although toxic responses occurred frequently (94% of samples) in urchin embryo development tests performed with 100% pore waters, toxicity diminished markedly in tests done with diluted pore waters. Microbial bioluminescent activity was not reduced to a great degree (no EC50 <0.06 mg/ml) and cytochrome P-450 activity was not highly induced (6 samples exceeded 37.1 ug/g benzo[a]pyrene equivalents) in tests done with organic solvent extracts. Urchin embryological development was highly correlated with concentrations of ammonia and many trace metals. Cytochrome P450 induction was highly correlated with concentrations of a number of classes of organic compounds (including the polynuclear aromatic hydrocarbons and chlorinated compounds). (PDF contains 51 pages

The Archaeology of 19th-Century Farmsteads: The Results of a Workshop Held at the 1997 Annual Meeting of the Council for Northeast Historical Archaeology

A workshop was held at the 1997 annual meeting of the Council for Northeast Historical Archaeology (CNEHA) to address the question What do we do with 19th-century farmsteads in the Northeast? The workshop involved several brainstorming sessions in which the participants examined topics and problems associated with current approaches to the archaeological investigation of farmstead sites. These brainstorming sessions examined questions such as: What is a 19th-century farmstead? What are the research and public values of these sites? Which sites should be examined? and How should these sites be investigated? The workshop ended with the development of an action agenda with recommendations on how we as a discipline, and CNEHA as an organization, should proceed with the research, interpretation, and preservation of these types of sites

Predictors of Long-Term Victimization After Early Pediatric Traumatic Brain Injury

Pediatric traumatic brain injuries (TBIs) adversely affect long-term functional and social outcomes. Limited research suggests children with TBI are more likely to be victimized by peers than noninjured children. Deficits in social information processing (SIP), cognitive ability, and executive functioning (EF) may contribute to increased victimization risk. This study examined rates of peer victimization/bullying in children with early TBI compared with children with orthopedic injuries (OIs) and the role of processing speed, executive function (EF), and SIP as mediators of the association of TBI and peer victimization

Characterization of Subsurface Polycyclic Aromatic Hydrocarbons at the Deepwater Horizon Site

Here, we report the initial observations of distributions of polycyclic aromatic hydrocarbons (PAH) in subsurface waters near the Deepwater Horizon oil well site (also referred to as the Macondo, Mississippi Canyon Block 252 or MC252 well). Profiles of in situ fluorescence and beam attenuation conducted during 9-16 May 2010 were characterized by distinct peaks at depths greater than 1000 m, with highest intensities close to the wellhead and decreasing intensities with increasing distance from the wellhead. Gas chromatography/mass spectrometry (GC/MS) analyses of water samples coinciding with the deep fluorescence and beam attenuation anomalies confirmed the presence of polycyclic aromatic hydrocarbons (PAH) at concentrations reaching 189 mu g L(-1) (ppb). Subsurface exposure to PAH at levels considered to be toxic to marine organisms would have occurred in discrete depth layers between 1000 and 1400 m in the region southwest of the wellhead site and extending at least as far as 13 km. Citation: Diercks, A.-R., et al. (2010), Characterization of subsurface polycyclic aromatic hydrocarbons at the Deepwater Horizon site, Geophys. Res. Lett., 37, L20602, doi: 10.1029/2010GL045046