Biomedical subjects

E R Kline

Publications and source records attributed to E R Kline.

5 recordsLinked to original sources

PubMed2001

Colonization of mine tailings by marine invertebrates.

An experiment was conducted to determine if a tailings substrate would inhibit recolonization of benthic macrofauna upon closure of a submarine tailings disposal (STD) operation. Trays of defaunated marine sediment, serving as a reference, and trays of tailings from a proposed gold mine were placed at 21 m depth on the ocean floor to allow colonization via settlement from the water column. Trays of reference sediment and tailings, and cores of ambient sediment were collected 9, 17, and 22 months after tray placement. Probable tray effects, which were desirable given the objectives of this study, precluded direct comparison of ecological succession in the tray sediments to the ambient assemblage. The ambient macrofauna assemblage was distinguishable from the reference sediment and tailings assemblages throughout the experiment and displayed more pronounced seasonality. Differences between the reference sediment and tailings assemblages were generally insignificant, including total abundance, total biomass, number of taxa, average size of individuals, numerically dominant taxa, abundance by ecological guilds, and overall community composition. Upon cessation of STD, recolonization of a benthic macrofauna community should not be inhibited by the presence of these tailings as a benthic substrate.

Animals↗

PubMed1996

Design and construction of model stream ecosystems.

A series of 12 outdoor model stream mesocosms was designed to evaluate the effects of chemicals and mixtures on the biota in stream ecosystems. An integrated design plan incorporated physical, chemical, and biological factors as well as the specific experimental objectives and effects parameters to be evaluated. Analysis of biological assemblages such as macroinvertebrates and periphyton in the model stream mesocosms demonstrated the presence of diverse and sensitive taxa. These model stream mesocosms also included the ability to evaluate responses of sentinel fish species such as Pimephales promelas and Lepomis macrochirus as well as macrophytes. The design and construction of the stream are discussed in detail and a brief description of a typical experimental protocol is provided. Experiments, to date, have spanned 14-30 days pretreatment "colonization" with 30 days of treatment and 15 days of posttreatment observation. Precision and accuracy of test chemical delivery to the stream have been excellent and the overall experimental design has been useful for delivering threshold toxicity concentrations and evaluating ecosystem potency for the chemicals tested.

Analysis of Variance↗

PubMed1989

Acute toxicity of triphenyltin hydroxide to three cladoceran species.

The toxicity of an organotin pesticide, triphenyltin hydroxide, was assessed with several freshwater cladoceran species. Daphnia pulex, Daphnia magna, and Ceriodaphnia dubia were exposed for 48 h to triphenyltin hydroxide in static acute toxicity tests. Values of the 48-h trimmed Spearman-Karber EC(50)s for the three species were found to be 14.5, 16.5, and 11.3 microg litre(-1), respectively. Analysis of variance performed on EC(50) values of replicates revealed no significant differences between the three species. Methods were employed which decrease animal handling stress and increase the accuracy and precision of the concentrations.

Journal Article↗

PubMed1988

Toxicity of chlorpyrifos, endrin, or fenvalerate to fathead minnows following episodic or continuous exposure.

Fathead minnow larvae (Pimephales promelas) were exposed to three individual pesticides during brief or continuous exposure in 96-hr and 28- to 30-day toxicity tests. Continuous exposure 96-hr LC50 values for chlorpyrifos, endrin, and fenvalerate were 122.2, 0.7, and 0.85 micrograms/liter, respectively. Continuous exposure chronic effect concentrations were chlorpyrifos, 2.1 micrograms/liter (increased deformities); endrin, 0.38 micrograms/liter (reduction in growth); and fenvalerate, 0.36 micrograms/liter (reduction in survival and growth). Brief exposure chronic test results indicated that fathead minnow exposure to chlorpyrifos for as few as 5 hr at a concentration similar to a continuous exposure 96-hr LC50 value resulted in increased deformities and a reduction in growth, whereas a 48-hr exposure at a concentration similar to a continuous exposure 96-hr LC50 value was required to cause a reduction in growth for endrin and a reduction in survival and growth for fenvalerate. It is suggested that although constant exposure laboratory tests are essential for hazard assessment, the relationships of exposure duration and toxicant intensity to ecotoxic effects are necessary for reliable risk assessments and implementation of water quality standards.

Animals↗

PubMed1988

Acute and chronic toxicity of triphenyltin hydroxide to fathead minnows (Pimephales promelas) following brief or continuous exposure.

Fathead minnow larvae (Pimephales promelas) were exposed to triphenyltin hydroxide (TPTH) during brief (single pulse) or continuous exposure in 96-h and 30-day toxicity tests. The continuous exposure 96-h LC(50) value was 7.1 microg litre(-1). Brief exposures for 12 to 72-h gave 96-h LC(50) values that ranged from 61.8 to 6.0 microg litre(-1), respectively. The continuous exposure 30-day chronic effect concentration, based upon reduced growth, was 0.23 microg litre. Survival was significantly reduced at 2.0 microg litre(-1). Brief exposures for 24, 48, and 72-h in 30-day tests significantly reduced survival and growth at 13.0, 13.0 and 60.0 microg litre(-1) respectively. It is suggested that both toxicant concentration and exposure duration are important factors to consider in the risk assessment of potential pesticide hazards in the environment.

Journal Article↗