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J.M. Biedenbach

Publications and source records attributed to J.M. Biedenbach.

7 recordsLinked to original sources

Influence of potentially confounding factors on sea urchin porewater toxicity tests

The influence of potentially confounding factors has been identified as a concern for interpreting sea urchin porewater toxicity test data. The results from >40 sediment-quality assessment surveys using early-life stages of the sea urchin Arbacia punctulata were compiled and examined to determine acceptable ranges of natural variables such as pH, ammonia, and dissolved organic carbon on the fertilization and embryological development endpoints. In addition, laboratory experiments were also conducted with A. punctulata and compared with information from the literature. Pore water with pH as low as 6.9 is an unlikely contributor to toxicity for the fertilization and embryological development tests with A. punctulata. Other species of sea urchin have narrower pH tolerance ranges. Ammonia is rarely a contributing factor in pore water toxicity tests using the fertilization endpoint, but the embryological development endpoint may be influenced by ammonia concentrations commonly found in porewater samples. Therefore, ammonia needs to be considered when interpreting results for the embryological development test. Humic acid does not affect sea urchin fertilization at saturation concentrations, but it could have an effect on the embryological development endpoint at near-saturation concentrations. There was no correlation between sediment total organic carbon concentrations and porewater dissolved organic carbon concentrations. Because of the potential for many varying substances to activate parthenogenesis in sea urchin eggs, it is recommended that a no-sperm control be included with every fertilization test treatment. ?? 2006 Springer Science+Business Media, Inc.

Archives of Environmental Contamination and Toxico↗

Toxicological and chemical assessment of ordnance compounds in marine sediments and porewaters

Toxicological and chemical studies were performed with a silty and a sandy marine sediment spiked with 2,6-dinitrotoluene (2,6-DNT), 2,4,6-trinitrophenylmethylnitramine (tetryl), or 2,4,6-trinitrophenol (picric acid). Whole sediment toxicity was analyzed by the 10-day survival test with the amphipod Ampelisca abdita, and porewater toxicity tests assessed macro-algae (Ulva fasciata) zoospore germination and germling growth, sea urchin (Arbacia punctulata) embryological development, and polychaete (Dinophilus gyrociliatus) survival and reproduction. Whole sediments spiked with 2,6-DNT were not toxic to amphipods. The fine-grained sediment spiked with tetryl was also not acutely toxic. The tetryl and picric acid LC50 values in the sandy sediment were 3.24 and 144 mg/kg dry weight, respectively. The fine-grained sediment spiked with picric acid generated a U-shaped concentration-response curve in the amphipod test, with increased survival both in the lowest and highest concentration. Grain-size distribution and organic carbon content strongly influenced the behavior of ordnance compounds in spiked sediments. Very low concentrations were measured in some of the treatments and irreversible binding and biodegradation are suggested as the processes responsible for the low measurements. Porewater toxicity varied with its sedimentary origin and with ordnance compound. The sea urchin embryological development test tended to be the least sensitive. Tetryl was the most toxic chemical in all porewater tests, and picric acid the least toxic. Samples spiked with 2,6-DNT contained a degradation product identified as 2-methyl-3-nitroaniline (also known as 2-amino-6-nitrotoluene), and unidentified peaks, possibly degradation products, were also seen in some of the picric acid- and tetryl-spiked samples. Degradation products may have played a role in observed toxicity. ?? 2002 Elsevier Science Ltd. All rights reserved.

Marine Pollution Bulletin↗

Effect of 2,4-Dichlorophenoxyacetic acid herbicide Escherichia coli growth, chemical, composition, and cellular envelope

2,4-Dichlorophenoxyacetic acid (2,4-D) is a herbicide widely used in the world and mainly excreted by the renal route in exposed humans and animals. Herbicides can affect other nontarget organisms, such as Escherichia coli. We observed that a single exposure to 1 mM 2,4-D diminished growth and total protein content in all E. coli strains tested in vitro. In addition, successive exposures to 0.01 mM 2,4-D had a toxic effect decreasing growth up to early stationary phase. Uropathogenic E. coli adhere to epithelial cells mediated by fimbriae, adhesins, and hydrophobic properties. 2,4-D exposure of uropathogenic E. coli demonstrated altered hydrophobicity and fimbriation. Hydrophobicity index values obtained by partition in p-xylene/water were 300-420% higher in exposed cells than in control ones. Furthermore, values of hemagglutination titer, protein contents in fimbrial crude extract, and electron microscopy demonstrated a significant diminution of fimbriation in treated cells. Other envelope alterations could be detected, such as lipoperoxidation, evidenced by decreased polyunsaturated fatty acids and increased lipid degradation products (malonaldehyde), and motility diminution. These alterations decreased cell adherence to erythrocytes, indicating a diminished pathogenic capacity of the 2,4-D-exposed E. coli. ?? 2001 by John Wiley & Sons, Inc.

Environmental Toxicology↗

Sediment toxicity identification evaluation (TIE) studies at marine sites suspected of ordnance contamination

A sediment quality assessment survey and subsequent toxicity identification evaluation (TIE) study was conducted at several sites in Puget Sound, Washington. The sites were previously suspected of contamination with ordnance compounds. The initial survey employed sea urchin porewater toxicity tests to locate the most toxic stations. Sediments from the most toxic stations were selected for comprehensive chemical analyses. Based on the combined information from the toxicity and chemical data, three adjacent stations in Ostrich Bay were selected for the TIE study. The results of the phase I TIE suggested that organics and metals were primarily responsible for the observed toxicity in the sea urchin fertilization test. In addition to these contaminants, ammonia was also contributing to the toxicity for the sea urchin embryological development test. The phase II TIE study isolated the majority of the toxicity in the fraction containing nonpolar organics with high log Kow, but chemical analyses failed to identify a compound present at a concentration high enough to be responsible for the observed toxicity. The data suggest that some organic or organometallic contaminant(s) that were not included in the comprehensive suite of chemical analyses caused the observed toxicological responses.

Archives of Environmental Contamination and Toxico↗

Development of marine toxicity data for ordnance compounds

A toxicity database for ordnance compounds was generated using eight compounds of concern and marine toxicity tests with five species from different phyla. Toxicity tests and endpoints included fertilization success and embryological development with the sea urchin Arbacia punctulata ; zoospore germination, germling length, and cell number with the green macroalga Ulva fasciata ; survival and reproductive success of the polychaete Dinophilus gyrociliatus ; larvae hatching and survival with the redfish Sciaenops ocellatus ; and survival of juveniles of the opossum shrimp Americamysis bahia (formerly Mysidopsis bahia ). The studied ordnance compounds were 2,4- and 2,6-dinitrotoluene, 2,4,6-trinitrotoluene, 1,3-dinitrobenzene, 1,3,5-trinitrobenzene, 2,4,6-trinitrophenylmethylnitramine (tetryl), 2,4,6-trinitrophenol (picric acid), and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The most sensitive toxicity test endpoints overall were the macroalga zoospore germination and the polychaete reproduction tests. The most toxic ordnance compounds overall were tetryl and 1,3,5-trinitrobenzene. These were also the most degradable compounds, often being reduced to very low or below-detection levels at the end of the test exposure. Among the dinitro- and trinitrotoluenes and benzenes, toxicity tended to increase with the level of nitrogenation. Picric acid and RDX were the least toxic chemicals tested overall.

Archives of Environmental Contamination and Toxico↗

Use of power analysis to develop detectable significance criteria for sea urchin toxicity tests

When sufficient data are available, the statistical power of a test can be determined using power analysis procedures. The term “detectable significance” has been coined to refer to this criterion based on power analysis and past performance of a test. This power analysis procedure has been performed with sea urchin ( Arbacia punctulata ) fertilization and embryological development data from sediment porewater toxicity tests. Data from 3100 and 2295 tests for the fertilization and embryological development tests, respectively, were used to calculate the criteria and regression equations describing the power curves. Using Dunnett's test, a minimum significant difference (MSD) ( β = 0.05) of 15.5% and 19% for the fertilization test, and 16.4% and 20.6% for the embryological development test, for α ≤ 0.05 and α ≤ 0.01, respectively, were determined. The use of this second criterion reduces type I (false positive) errors and helps to establish a critical level of difference based on the past performance of the test.

Aquatic Ecosystem Health & Management↗

Sediment porewater toxicity assessment studies in the vicinity of offshore oil and gas production platforms in the Gulf of Mexico

As part of a multidisciplinary program to assess the potential long-term impacts of offshore oil and gas exploration and production activities in the Gulf of Mexico, sediment chemical analyses and porewater toxicity tests were conducted in the vicinity of five offshore platforms. Based on data from sea urchin fertilization and embryological development assays, toxicity was observed near four of the five platforms sampled; the majority of the toxic samples were collected within 150 m of a platform. There was excellent agreement among the results of porewater tests with three different species (sea urchin embryological development, polychaete reproduction, and copepod nauplii survival). The sediment concentrations of several metals were well in excess of sediment quality assessment guidelines at a number of stations, and good agreement was observed between predicted and observed toxicity. Porewater metal concentrations compared with EC50, LOEC, and NOEC values generated for water-only exposures indicated that the porewater concentrations for several metals were high enough to account for the observed toxicity. Results of these studies utilizing highly sensitive toxicity tests suggest that the contaminant-induced impacts from offshore platforms are limited to a localized area in the immediate vicinity of the platforms.

Canadian Journal of Fisheries and Aquatic Sciences↗