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A.J. Paulson

Publications and source records attributed to A.J. Paulson.

7 recordsLinked to original sources
USGS2018

Mercury methylation and bioaccumulation in Sinclair Inlet, Kitsap County, Washington

The U.S. Geological Survey evaluated the transformation of mercury to bioavailable methylmercury in Sinclair Inlet, Kitsap County, Washington, and assessed the effect of the transformation processes on the mercury burden in marine organisms and sediment. In August 2008, samples of sediment, water, and biota from six sites in Sinclair Inlet and three bays representative of Puget Sound embayments were collected. The extensive sediment sampling included analysis of methylmercury in sediment and porewater, estimates of methylation production potential, and analyses of ancillary constituents associated with organic carbon and reduction-oxidation (redox) conditions to assist in interpreting the mercury results. Analyses of methylmercury in water overlying incubated cores provided an estimate of the release of methylmercury to the water column. Collection of samples for mercury species in the aqueous, particulate (suspended solids), and biological phases, and for ancillary carbon and nitrogen constituents in surface water, continued, on about a monthly schedule, at four stations through August 2009. In February, June, and August 2009, seasonal sediment samples were collected at 20 stations distributed between greater Sinclair Inlet and Operable Unit B Marine of the Bremerton naval complex, Bremerton, Washington, to examine geographical and seasonal patterns of mercury biogeochemistry of sediment in Sinclair Inlet. At six of these seasonal sediment stations, porewater was collected and triplicate core incubation experiments were done. Median sediment-methylmercury concentrations were not statistically different between the representative bays and Sinclair Inlet. The percentage of sediment methylmercury (relative to total mercury) was actually lower in the Sinclair Inlet sites compared with the representative bays, reflecting the higher sediment total mercury concentration for the Sinclair Inlet stations compared with the representative bays. Likewise, median sediment methylmercury concentrations were not statistically different between the greater Sinclair Inlet stations and the Bremerton naval complex stations; whereas the percentage of sediment methylmercury to total mercury was lower in the Bremerton naval complex due to higher sediment total mercury concentrations than the greater Sinclair Inlet stations. The biogeochemical characteristics of each station, measured by redox, organic carbon, and the seasonal availability of nutrients controlled methylmercury biogeochemistry. Mercury methylation production potential was a function of temperature, concentration of total mercury in sediment, and the percentage of ferrous iron (relative to total measured iron) across all sites. Methylmercury porewater concentrations were best described by using concentrations of dissolved organic carbon and reduction-oxidation conditions. Likewise, the variable fluxes of methylmercury from incubated cores were best described using dissolved organic carbon and reduction-oxidation conditions. Sinclair Inlet exhibited the classic Puget Sound biological cycle, with spring and autumn phytoplankton blooms resulting in depletion of nitrate, orthophosphate, and silicate in the surface water. Although variable in timing between 2008 and 2009, a strong corresponding seasonal trend of increased availability, incorporation, and bioaccumulation of methylmercury into the food web of Sinclair Inlet occurred during the early spring and summer growing season.

Washington↗
USGS2012

Mercury species and other selected constituent concentrations in water, sediment, and biota of Sinclair Inlet, Kitsap County, Washington, 2007-10

This report presents data collected for two U.S. Geological Survey field sampling projects related to mercury (Hg) in Sinclair Inlet: (1) the Watersheds Sources Project that evaluated the sources of mercury to Sinclair Inlet during December 2007 to March 2010, and (2) the Methylation and Bioaccumulation Project, a comprehensive examination of mercury biogeochemistry in sediment, water, and zooplankton during August 2008–February 2010. For the Watershed Sources project, nonpoint and point sources of mercury to Sinclair Inlet from the Bremerton naval complex (BNC) were evaluated by using filtered total mercury and particulate total mercury measured in water samples collected from 11 wells, 2 dry dock sump discharges, and a steam plant's effluent at the BNC. Methylmercury sources to the inlet were examined by determining filtered methylmercury concentrations in water samples collected from five wells, two dry dock sump discharges, a steam plant's effluent, five intertidal piezometers, and three stormwater drains on the BNC, as well as in samples from five creeks, two wastewater treatment facilities, and three stormwater drains in the Sinclair Inlet watershed outside of the BNC. An improved understanding of tidally modulated mercury migration to Sinclair Inlet from the BNC was gained through three intensive nearshore (tidal) sampling events of mercury species in groundwater and a nearby stormwater drain. The Methylation and Bioaccumulation Project included a comprehensive field study of mercury biogeochemistry in marine sediment, water, and zooplankton in Sinclair Inlet. Mercury, iron, and sulfur species in sediment porewater from six sites within and three sites outside of Sinclair Inlet were measured to provide insight into the processes that produce methylmercury in the sediments. Total mercury, methylmercury, dissolved organic carbon, and redox-sensitive species were measured in porewaters in the top 2 centimeters of sediment, and these data were paired with sedimentary flux measurements from core incubation experiments to connect sedimentary processes to the water column. A broad-scale study of mercury methylation potential and mercury species at 20-plus stations in Sinclair Inlet was conducted in February 2009 and 2010, June 2009, and August 2009. Sedimentary flux measurements and analysis of mercury and biogeochemicals in sediment porewater and bottom water were made at six of the broad-scale stations. Bioaccumulation processes in the water column in the context of the sedimentary flux of methylmercury were examined using monthly survey data collected between August 2008 and August 2009. The survey data included concentrations of methylmercury and isotope ratios of carbon and nitrogen in bulk zooplankton measured at four stations in Sinclair Inlet in the context of the population of bulk zooplankton ascertained by taxonomical identification. The analysis of filtered total mercury, total particulate mercury, filtered methylmercury, particulate methylmercury, chlorophyll a, isotopes of carbon and nitrogen in suspended matter, and other biogeochemical data will facilitate the examination of the biogeochemistry of mercury in Sinclair Inlet.

Washington↗
USGS2007

Mercury sedimentation in lakes in western Whatcom County, Washington, USA and its relation to local industrial and municipal atmospheric sources

Concentrations of mercury (Hg) were measured in six dated cores from four lakes in western Whatcom County, Washington, USA, that were at various bearings from a chlor-alkali plant, two municipal waste incinerators and a municipal sewage sludge incinerator. The importance of atmospheric emissions of Hg from these local municipal and industrial sources was evaluating by comparing the temporal trends in sedimentation of the lake cores with the emission history of each Hg species and by examining the geographical distribution of Hg sedimentation in relation to the region's primary wind pattern. Local municipal and industrial sources of atmospheric Hg were not responsible for the majority of the Hg in the upper layer of sediments of Whatcom County lakes because of (1) the significant enrichment of Hg in lake sediments prior to emissions of local industrial and municipal sources in 1964, (2) smaller increases in Hg concentrations occurred after 1964, (3) the similarity of maximum enrichments found in Whatcom County lakes to those in rural lakes around the world, (4) the inconsistency of the temporal trends in Hg sedimentation with the local emission history, and (5) the inconsistency of the geographic trends in Hg sedimentation with estimated deposition. Maximum enrichment ratios of Hg in lake sediments between 2 and 3 that are similar to rural areas in Alaska, Minnesota, and New England suggest that global sources of Hg were primarily responsible for increases of Hg in Whatcom County lakes beginning about 1900. ?? 2007 GovernmentEmployee: U.S. Government, Department of Interior, U.S. Geological Survey.

Water, Air, & Soil Pollution↗
USGS2007

Geochemical and geophysical examination of submarine groundwater discharge and associated nutrient loading estimates into Lynch Cove, Hood Canal, WA

Geochemical tracer data (i.e., 222 Rn and four naturally occurring Ra isotopes), electromagnetic (EM) seepage meter results, and high-resolution, stationary electrical resistivity images were used to examine the bi-directional (i.e., submarine groundwater discharge and recharge) exchange of a coastal aquifer with seawater. Our study site for these experiments was Lynch Cove, the terminus of Hood Canal, WA, where fjord-like conditions dramatically limit water column circulation that can lead to recurring summer-time hypoxic events. In such a system a precise nutrient budget may be particularly sensitive to groundwater-derived nutrient loading. Shore-perpendicular time-series subsurface resistivity profiles show clear, decimeter-scale tidal modulation of the coastal aquifer in response to large, regional hydraulic gradients, hydrologically transmissive glacial terrain, and large (4-5 m) tidal amplitudes. A 5-day 222 Rn time-series shows a strong inverse covariance between 222 Rn activities (0.5−29 dpm L -1 ) and water level fluctuations, and provides compelling evidence for tidally modulated exchange of groundwater across the sediment/water interface. Mean Rn-derived submarine groundwater discharge (SGD) rates of 85 ± 84 cm d -1 agree closely in the timing and magnitude with EM seepage meter results that showed discharge during low tide and recharge during high tide events. To evaluate the importance of fresh versus saline SGD, Rn-derived SGD rates (as a proxy of total SGD) were compared to excess 226Ra-derived SGD rates (as a proxy for the saline contribution of SGD). The calculated SGD rates, which include a significant (>80%) component of recycled seawater, are used to estimate associated nutrient (NH 4+ , Si, PO 4 3- , NO 3 + NO 2 , TDN) loads to Lynch Cove. The dissolved inorganic nitrogen (DIN = NH 4 + NO 2 + NO 3 ) SGD loading estimate of 5.9 × 10 4 mol d -1 is 1−2 orders of magnitude larger than similar estimates derived from atmospheric deposition and surface water runoff, respectively.

Washington↗
USGS2006

Surface-water quality in rivers and drainage basins discharging to the southern part of Hood Canal, Mason and Kitsap Counties, Washington, 2004

Concentrations of nutrients, major ions, organic carbon, suspended sediment, and the nitrogen isotope ratio of nitrate (delta15N) were collected at surface-water sites in rivers and drainage basins discharging to the southern part of Hood Canal, Mason and Kitsap Counties, Washington. Base-flow samples were collected from sites on the Union, Tahuya, and Skokomish Rivers from June to August 2004. Concentrations of nutrients at all sites were low. Ammonia and orthophosphate were less than the detection limit for most samples, and nitrate plus nitrite concentrations ranged from less than the detection limit of 0.06 to 0.49 milligram per liter (mg/L). Nitrate plus nitrite concentrations were near the detection limit of 0.06 mg/L in the North Fork, South Fork, and mainstem of the Skokomish River. The concentration of nitrate plus nitrite in the Tahuya River system above Lake Tahuya was 0.17 mg/L, but decreased to 0.1 mg/L or less downstream of Lake Tahuya. Overall, the Union River contained the highest nitrate plus nitrite concentrations of the three large river systems, ranging from 0.12 to 0.28 mg/L. delta15N generally was within the range that encompasses most sources, providing little information on nitrate sources. Most nitrogen was in the dissolved inorganic form. Dissolved inorganic nitrogen in Lake Tahuya was converted into particulate and dissolved organic nitrogen. Dissolved organic carbon concentrations generally were less than 1 mg/L in the Tahuya and Skokomish Rivers and averaged 1.3 mg/L in the Union River. Dissolved organic carbon concentrations of 2.6 to 2.7 mg/L at sites just downstream of Lake Tahuya were highest for the three large river systems, and decreased to concentrations less than 1 mg/L, which was similar to concentrations in the Skokomish River. Total nitrogen concentrations near 0.5 mg/L were measured at two sites: Unnamed Creek at Purdy-Cutoff Road (site S2b) and downstream of Lake Devereaux (site SP5). Concentrations of nitrate plus nitrite were highest at site S2b (0.49 mg/L), and dissolved organic carbon concentrations (3.3 mg/L) were highest at the outlet of Lake Devereaux. However, the overall impact of these sites on the nutrient loading to Hood Canal probably is negligible because of the low streamflow and small loads. Springtime samples were collected from the Union River, Tahuya River, Mission Creek, and three smaller drainage basins in March 2004. Samples were collected during spring rain events to determine if increased runoff contributes larger amounts of sediment and nutrients from the land into the surface water. There was little difference in nutrient concentrations between samples collected in the spring and base-flow samples collected in the summer. This is likely due to the fact that the springtime samples were collected during a rain event and not necessarily during a peak in the hydrograph.

Scientific Investigations Report↗
USGS2005

Tracing water and suspended matter in Raritan and Lower New York Bays using dissolved and particulate elemental concentrations

Geochemical tracers were used to examine the mixing of water and particles in Lower New York and Raritan Bays in August 1999 during low-flow conditions. Four brackish water masses (20 ≤ S ≤ 28) originating in the Raritan and Shrewsbury Rivers, Arthur Kill, and Upper New York Bay were characterized by their dissolved metals concentrations. The mixing lines of dissolved Cu, Ni, and Pb in Lower New York Bay were similar to those in Upper New York Bay, the source of most of the freshwater to the system. Dissolved Cd and Mn seemed to have been removed by particles in several regions of the study. Dissolved Cu, Ni and Pb in the Raritan River fell below the mixing lines of the Lower New York Bay. In contrast, the concentrations of dissolved Co and Mn in the Raritan River were distinctly higher than those in the Lower New York Bay, while dissolved Cu and Ni were elevated in the Arthur Kill. A plot of dissolved Co versus dissolved Ni clearly differentiated among three water masses: (1) Upper and Lower New York Bays and Sandy Hood Bay, (2) the Raritan River, and (3) Arthur Kill–Raritan Bay–Shrewsbury River. The concentrations of 22 elements also were measured in the suspended matter of Raritan and Lower New York Bays and brackish water sources. The elemental composition of the suspended matter in surface and bottom waters was correlated with Fe concentrations, which ranged between 50 and 900 μmol g − 1 . Statistical differences among the geographical regions were detected in the relationships of Ti, Ni, Co, As, and U with Fe, with particulate As being an especially strong geochemical indicator of Raritan River particles. The geochemical signatures of Lower New York Bay particles were similar to those of Upper New York Bay. The geochemical signatures of Raritan River particles were distinctly different than those of the Upper New York Bay, but the influence of Raritan River particles appeared to be limited to only inner Raritan Bay. This study illustrates the utility of trace elements for characterization of physical processes in complex estuaries.

Marine Chemistry↗