Using the Sediment Quality Triad to characterize baseline conditions in the Anacostia River, Washington, DC, USA.

The Sediment Quality Triad (SQT) consists of complementary measures of sediment chemistry, benthic community structure, and sediment toxicity. We applied the SQT at 20 stations in the tidal portion of the Anacostia River from Bladensburg, MD to Washington, DC to establish a baseline of conditions to evaluate the effects of management actions. Sediment toxicity was assessed using 10-day survival and growth tests with the freshwater amphipod, Hyalella azteca and the midge, Chironomus dilutus. Triplicate grabs were taken at each station for benthic community analysis and the Benthic Index of Biotic Integrity (B-IBI) was used to interpret the data. Only one station, #92, exhibited toxicity related to sediment contamination. Sediments from this station significantly inhibited growth of both test species, had the highest concentrations of contaminants, and had a degraded benthic community, indicated by a B-IBI of less than 3. Additional sediment from this station was tested and sediment toxicity identification evaluation (TIE) procedures tentatively characterized organic compounds as the cause of toxicity. Overall, forty percent of the stations were classified as degraded by the B-IBI. However, qualitative and quantitative comparisons with sediment quality benchmarks indicated no clear relationship between benthic community health and contaminant concentrations. This study provides a baseline for assessing the effectiveness of management actions in the Anacostia River.

Erratum to: Effects-based spatial assessment of contaminated estuarine sediments from Bear Creek, Baltimore Harbor, MD, USA.

The original publication of this paper contains an error. The correct image of figure 5 is shown in this paper.

Correction to: Effects-based spatial assessment of contaminated estuarine sediments from Bear Creek, Baltimore Harbor, MD, USA.

The authors of the article have informed the Journal that an author, Dr. Sacoby Wilson of the University of Maryland School of Public Health, was inadvertently omitted from the published version of their manuscript due to a miscommunication regarding authorship criteria.

Effects-based spatial assessment of contaminated estuarine sediments from Bear Creek, Baltimore Harbor, MD, USA.

Estuarine sediments in regions with prolonged histories of industrial activity are often laden to significant depths with complex contaminant mixtures, including trace metals and persistent organic pollutants. Given the complexity of assessing risks from multi-contaminant exposures, the direct measurement of impacts to biological receptors is central to characterizing contaminated sediment sites. Though biological consequences are less commonly assessed at depth, laboratory-based toxicity testing of subsurface sediments can be used to delineate the scope of contamination at impacted sites. The extent and depth of sediment toxicity in Bear Creek, near Baltimore, Maryland, USA, was delineated using 10-day acute toxicity tests with the estuarine amphipod Leptocheirus plumulosus, and chemical analysis of trace metals and persistent organic pollutants. A gradient of toxicity was demonstrated in surface sediments with 21 of 22 tested sites differing significantly from controls. Effects were most pronounced (100% lethality) at sites proximate to a historic industrial complex. Sediments from eight of nine core samples to depths of 80 cm were particularly impacted (i.e., caused significant lethality to L. plumulosus) even in locations overlain with relatively non-toxic surface sediments, supporting a conclusion that toxicity observed at the surface (top 2 cm) does not adequately predict toxicity at depth. In seven of nine sites, toxicity of surface sediments differed from toxicity at levels beneath by 28 to 69%, in five instances underestimating toxicity (28 to 69%), and in two instances overestimating toxicity (44 to 56%). Multiple contaminants exceeded sediment quality guidelines and correlated positively with toxic responses within surface sediments (e.g., chromium, nickel, polycyclic aromatic hydrocarbon (PAH), total petroleum hydrocarbon). Use of an antibody-based PAH biosensor revealed that porewater PAH concentrations also increased with depth at most sites. This study informs future management decisions concerning the extent of impact to Bear Creek sediments, and demonstrates the benefits of a spatial approach, relying primarily on toxicity testing to assess sediment quality in a system with complex contaminant mixtures.

A field test and comparison of acute and chronic sediment toxicity tests with the estuarine amphipod Leptocheirus plumulosus in Chesapeake Bay, USA.

A 28-d partial life-cycle test with the estuarine amphipod Leptocheirus plumulosus was developed in response to the need for an assay to mimic chronic exposure to sediment-associated contaminants. To ensure that toxicity tests have environmental relevance, it is essential to evaluate the relationship between laboratory responses and field measures of contamination. Consequently, one objective of the study was to compare the results of the chronic sediment toxicity test with L. plumulosus to gradients of sediment contamination and the in situ benthic community in its native Chesapeake Bay. Chronic tests were conducted by two laboratories, the Army Corps of Engineers Waterways Experiment Station ([WES]; Vicksburg, MS, USA) and the University of Maryland ([UM] College Park, MD, USA) using different feeding regimes, providing the opportunity to evaluate the effect of this variable on response sensitivity. A second objective was to compare the relative sensitivity of acute and chronic tests with L. plumulosus with field-collected sediments. Overall, there was good agreement between the toxicological response of acute and chronic tests with L. plumulosus and field measures of contamination. Survival in the acute test and chronic test conducted by WES was negatively correlated with concentrations of sediment-associated contaminants. Survival in acute exposures was significantly reduced in sediments from 8 of 11 stations. Indigenous L. plumulosus were found only at two of the three stations that did not exhibit acute toxicity. An unexpected finding was the difference in responsiveness of the two chronic tests. Survival in tests conducted by UM and WES was significantly reduced in sediments from 4 and 6 of 11 stations, respectively. No additional sublethal toxicity was detected in the UM chronic test, but the WES test detected reproductive effects at two additional stations. We believe the observed differences were related to the test diet used. Partly as a result of our findings, the recommended diet for the L. plumulosus chronic test was changed in the final methods document.

Poultry litter-induced endocrine disruption in fathead minnow, sheepshead minnow, and mummichog laboratory exposures.

Animal feeding operations in the United States produce more than 500 million tons of manure annually. Disposal of poultry waste via application as fertilizer results in substantial runoff of poultry litter-associated contaminants (PLAC). Of particular concern are sex steroids, 17ß-estradiol, estrone and testosterone, responsible for sex differentiation and development of reproductive structures. In a series of laboratory assays, mature male and mixed-sex larval/juvenile fish were continuously exposed to environmentally relevant PLAC solutions. Effects on gonads were assessed histologically, and vitellogenin (VTG) induction was measured as a gauge of estrogenicity. Twenty-one-day exposures to laboratory-generated PLAC solutions routinely induced VTG in mature male Pimephales promelas. Vitellogenesis in Fundulus heteroclitus only occurred at the highest tested PLAC concentration, and Cyprinodon variegatus were unresponsive at any tested concentration. All species produced considerable VTG in response to a 17ß-estradiol-positive control. A pronounced feminization was seen in P. promelas when exposed to PLAC as larvae but not when exposed as juveniles. Runoff from a poultry litter-amended field cropped under standard agronomic practices induced significant VTG in male P. promelas. Results indicate that environmentally relevant PLAC concentrations exhibit endocrine activity sufficient to induce VTG production in male fish and possibly affect sex ratios in resident fish populations.

Assessment of sediment contamination, acute toxicity, and population viability of the estuarine amphipod Leptocheirus plumulosus in baltimore harbor, maryland, USA.

In Chesapeake Bay, Maryland, USA, some of the most contaminated sediments are found in the highly industrialized Baltimore Harbor-Patapsco River area. As part of a comprehensive assessment of sediment quality in this system, sediment toxicity was assessed in 10-d acute tests with the estuarine amphipod Leptocheirus plumulosus. Mean amphipod survival was significantly reduced in 7 of the 25 samples tested despite the occurrence of minor experimental artifacts. The most toxic sediments were collected from Bear Creek; other areas exhibiting toxicity included the Inner Harbor and Colgate Creek. Marginal toxicity was observed in samples from Curtis Creek, Lazeretto Point, and Back River. Negative relationships were detected between survival and concentrations of select sediment-associated contaminants, whereas a very strong positive association existed between survival in laboratory exposures and density of L. plumulosus at the test sites. A weight of evidence approach, including correlation analyses, a model of polycyclic aromatic hydrocarbon bioavailability, and comparisons to benchmark sediment levels, was used to tentatively identify classes of contaminants that contributed to the observed toxicity. Analysis of results suggested that toxicity at stations in Bear Creek and Colgate Creek may have been driven by sediment-associated metals, whereas toxicity at stations in the Inner Harbor was likely due to both metal and organic contaminants. The observed relationships among toxicity test results, concentrations of sediment-associated contaminants, and abundance of L. plumulosus at the test sites suggests that acute toxicity tests with this species are indicative of adverse biological effects in the field.