Product Citations and Abstracts

In conjunction with a fire ant eradication program during which mirex was aerially applied to coastal areas near Charleston, S.C., field studies were conducted to monitor the movement and accumulation of mirex in the estuarine system. Collections of background and periodic posttreatment samples of water, bottom sediments, shrimp, crabs, fish, and estuary-dependent birds and mammals were analyzed for mirex using electron-capture gas chromatography. The data revealed that (1) mirex was translocated from treated lands and high marsh to estuarine biota--all animal classes sampled contained mirex; and (2) biological concentration of mirex occurred--especially in predators such as racoons and birds. Mirex residue ranges for respective sample categories were: water (less than 10.01 ppb); sediment (0-0.07 ppm); crabs (0-0.60 ppm); fishes (0-0.82 ppm); shrimps (0-1.3 ppm); mammals (0-4.4 ppm); and birds (0-17.0 ppm). No mass mortalities were observed during the study.

Borthwick, P.W., G.H. Cook and J.M. Patrick, Jr. 1974. Mirex Residues in Selected Estuaries of South Carolina--June 1972. Pestic. Monit. J. 7(3/4):144-145. (ERL,GB 168).

Estuarine sediments, crabs, shrimps, and fishes were collected in June 1972 at eleven stations two years after aerial applications of mirex bait for control of fire ants in coastal areas near Charleston, S.C. These stations had previously been monitored (October 1969 to June 1971) when levels of mirex in animal samples were: crabs, 0-0.60 ppm; shrimps, 0-1.3 ppm; and fishes, 0-0.82 ppm. The recent study showed that mirex was present in three species of fishes (white catfish, 0.21 ppm; bluegill, 0.47 ppm; carp, 0.12 ppm) and blue crabs (0.026 ppm) at two freshwater stations. However, mirex was not detected in 36 animal samples, most of which were taken from nine saline stations in the estuaries after a period of restriced use of the pesticide. Analysis of bottom sediment samples at all stations detected no mirex. The lower limit of detection for mirex was 0.01 ppm.

Borthwick, Patrick W., Marlin E. Tagatz and Jerrold Forester. 1975. Gravity-Flow Column to Provide Pesticide-Laden Water for Aquatic Bioassays. Bull. Environ. Contam. Toxicol. 13(2):183-187. (ERL,GB 189).

Concentrations of mirex among individual tanks in each test were not statistically different at the 5-percent significance level; whereas, differences in mirex concentrations in tank water among experiments were significant. Paired comparisons indicated statistical differences between the first and second, and the second and third experiments, but not between the first and third experiment. These differences in mean mirex concentrations in tank water may have been caused by seasonal variations in water temparature. Fluctuations in the mirex concentrations within individual tanks were not significant. In its present state of development, the described gravity-flow column is being utilized in seasonal tests to deliver mirex-laden water to determine toxicity and uptake of mirex by several animal species in an artificial estuarine ecosystem.

Borthwick, Patrick W. 1974. Clinical Centrifuge Tube for Small Blood Samples. Prog. Fish-Cult. 36(3):184. (ERL,GB 238).

Occasionally, large amounts of whole blood are difficult to obtain for physiological studies. Little blood is available when the animal is small (e.g. some fish and crustaceans) or when blood samples are taken periodically without sacrificing the animal. It is often difficult to obtain clear serum or plasma from small blood samples. In many microanalytical procedures (e.g. electrophoresis) only a few microliters of serum are needed, but the serum must be free of other blood components. Because of this, a simple and inexpensive device for separating components of small amounts of blood in a clinical-type centrifuge is described.

Borthwick, Patrick W. and Steven C. Schimmel. 1978. Toxicity of Pentachlorophenol and Related Compounds to Early Life Stages of Selected Estuarine Animals. In: Pentachlorophenol: Chemistry, Pharmacology, and Environmental Toxicology. EPA-600/J-78-076. K. Ranga Rao, Editor. Plenum Press, New York, NY. Pp. 141-146. (ERL,GB 343). (Avail. from NTIS, Springfield, VA: PB-290 073)

Newly hatched individuals of four estuarine species were exposed to pentachlorophenol (PCP), sodium pentachlorophenate (Na-PCP), or Dowicide® G (79% Na-PCP), in static toxicity tests. The 96-hour LC50 values for sheepshead minnow (Cyprinodon variegatus) fry exposed to PCP at ages 1-day, 2-wk, 4-wk, and 6-wk were 329, 392, 240, and 223 µg/l, respectively. The 96-hr LC50 value for 2-wk-old fry exposed to Dowicide® G was 516 µg/l. The larvae (48-hr post hatch) of pinfish, Lagodon rhomboides, were particularly sensitive to Na-PCP (96-hr LC50:38 µg/l) and Dowicide® G (96-hr LC50:66 µg/l). For 24-hr-old grass shrimp (Palaemonetes pugio) larvae exposed to Na-PCP the 96-hr LC50 was 649 µg/l. Na-PCP caused abnormal development of eastern oyster (Crassostrea virginica) embryos, the 48-hr EC50 being 40 µg/l.

Borthwick, Patrick W. and James M. Patrick. 1982. Use of Aquatic Toxicology and Quantitative Chemistry to Estimate Environmental Deactivation of Marine-Grade Creosote in Seawater. Environ. Toxicol. Chem. 1(4):281-288. (ERL,GB 421).

The acute toxicity of marine-grade creosote, expressed as the 96-h LC50, is 0.018 mg/l for mysids (Mysidopsis bahia, Molenock), .024 mg/l for pink shrimp (Penaeus durorum, Burkenroad), and 0.72 mg/l for sheepshead minnows (Cyprinodon variegatus, Lacepede). The 96-h EC50 (shell deposition) for Eastern oysters (Crassostrea virginica, Gmelin) is 0.71 mg/l. Mysid bioassays and chemical analyses estimate the half-life (<1 week) for marine-grade creosote in seawater.

Borthwick, P.W., J.R. Clark, R.M. Montgomery, J.M. Patrick, Jr. and E.M. Lores. 1985. Field Confirmation of a Laboratory-Derived Hazard Assessment of the Acute Toxicity of Fenthion to Pink Shrimp, Penaeus duorarum. In: Aquatic Toxicology and Hazard Assessment; Eighth Symposium, ASTM STP 891. EPA/600/D-85/033. R.C. Bahner and D.J. Hansen, Editors. American Society for Testing and Materials, Philadelphia, PA. Pp. 177-189. (ERL,GB 494). (Avail. from NTIS, Springfield, VA: PB85-169613)

Field studies were conducted to determine if laboratory protocols, accurately predict shrimp mortality under field conditions. To evaluate the applicability of laboratory data, fenthion, a mosquitocide, was applied to coastal black rush (Juncus roemerianus) marshes in several truck-mounted ultra-low volume (ULV) adulticide operations and by direct application at the larvicide rate. Caged pink shrimp (Penaeus duorarum) were deployed in floating, compartmented cages and observed frequently over a 24-h period for mortality. Water samples collected for gas chromatographic quantitation characterized the exposure concentration regime and fate of fenthion at the field sites. Field data were compared to laboratory acute toxicity data from ASTM standard practice flow-through tests. The acute flow-through 96-h LC50 of 0.11 µg/L was used as a conservative estimate of the expected toxicity in field exposures. An exposure profile based on measured field concentrations was used for laboratory pulse-exposure tests: fenthion was metered for 2 h to specified maximum concentrations, then flushed with seawater to cause a 6- to 8-h exposure, yielding a no-observed-effect concentration (NOEC) of 0.84 µg/L. In field tests, four ULV operations produced initial water concentrations NOEC) and caused extensive mortality (90 to 100%) in the caged shrimp. Thus, field observations confirmed our hypothesis that if fenthion time-exposure concentrations were lower than the laboratory NOEC, then no mortality would occur in caged shrimp. Moreover, if initial concentrations in the field exceeded the laboratory NOEC, mortality would occur. These laboratory tests and field applications indicate that laboratory toxicity tests can predict the range of lethal and nonlethal acute field exposures to fenthion for pink shrimp when exposure regimes are similar.

Borthwick, Patrick W., James M. Patrick, Jr. and Douglas P. Middaugh. 1985. Comparative Acute Sensitivities of Early Life Stages of Atherinid Fishes to Chlorpyrifos and Thiobencarb. EPA/600/J-85/122. Arch. Environ. Contam. Toxicol. 14(4):465-473. (ERL,GB 517). (Avail. from NTIS, Springfield, VA: PB86-100278/AS)

Sensitivity, expressed as the 96-hr LC50 derived from acute lethality tests, was compared for four ages (day-of-hatch, 7-day, 14-day, and 28-day) of three atherinid fishes: Leuresthes tenuis (California grunion), Menidia menidia (Atlantic silverside), and Menidia peninsulae (tidewater silverside). Responses of each age-species combination exposed to the organophosphate insecticide chlorpyrifos and the carbamate herbicide thiobencarb were compared in both static and flowing seawater toxicity tests. Chlorpyrifos was highly toxic to all atherinids (96-hr LC50's ranged from 0.4 to 6.7 µg/L); toxicity of thiobencarb was approximately two orders of magnitude lower (LC50 values from 199 to 1,405 µg/L). Responses to each pesticide were similar among the three species. Sensitivity was generally highest for 7-day and 14-day age groups, and flowing water tests were more sensitive measures of toxicity than static tests, especially for chlorpyrifos. Comparisons of three computational methods indicate that probit and moving average methods calculate comparable LC50 estimates with the binomial method being the least uniform point estimator.

Borthwick, Patrick W. and Roman S. Stanley. 1985. Effects of Ground ULV Applications of Fenthion on Estuarine Biota: III. Response of Caged Pink Shrimp and Grass Shrimp. EPA/600/J-85/463. J. Fla. Anti-Mosquito Assoc. 56(2):69-72. (ERL,GB 523c). (Avail. from NTIS, Springfield, VA: PB87-152781)

Estuarine grass shrimp (Palaemonetes pugio) and pink shrimp (Penaeus duorarum) were deployed in floating cages to determine if fenthion, in an actual-use application in the field, affected shrimp survival. After four ultra-low-volume ground applications (equivalent to 11g/ha or 0.01 lb/acre) to control salt marsh mosquitoes, deaths of caged grass shrimp or pink shrimp were not attributed to fenthion exposure. Suspect causes of reduced survival of shrimp include both low salinity and dissolved oxygen, daily excursions in water temperature, and stresses due to handling, acclimation, and confinement. Initial fenthion concentrations in seawater were sometimes within the range expected to kill shrimp in 48-h and 96-h laboratory exposures; however, pesticide concentrations were not sustained long enough to kill caged shrimp in the field. No signs of fenthion poisoning were observed among any of the caged shrimp.

Borthwick, Patrick W. and Gerald E. Walsh. 1981. Initial Toxicological Assessment of Ambush, Bolero, Bux, Dursban, Fentrifanil, Larvin, and Pydrin: Static Acute Toxicity Tests with Selected Estuarine Algae, Invertebrates, and Fish. EPA-600/4-81-076. U.S. Environmental Protection Agency, Environmental Research Laboratory, Gulf Breeze, FL. 9 p. (Avail. from NTIS, Springfield, VA: PB82-137654)

Selected static toxicity tests were conducted with Ambush, Bolero, Bux, Dursban, Fentrifanil, Larvin, and Pydrin to determine the sensitivity of species representing four major phyla. Algal bioassays were conducted with marine algae to determine the concentration of pesticide that would inhibit population growth by 50% in 96 h. Static toxicity tests with mollusk larvae estimated the concentration of pesticide that would cause 50% of the exposed larvae to develop abnormally in 48 h. Static acute lethality tests with crustaceans and fish determined the concentration of pesticide that is lethal to 50% of the test organisms during a 96-h exposure

Borthwick, Patrick W. 1978. Methods for Acute Static Toxicity Tests with Mysid Shrimp (Mysidopsis bahia). In: Bioassay Procedures for Ocean Disposal Permit Program. EPA-600/9-78-010. U.S. Environmental Protection Agency, Environmental Research Laboratory, Gulf Breeze, FL. Pp. 61-63. (ERL,GB X013).

Mysidopsis bahia is a shrimp-like estuarine crustacean that has been shown to be very sensitive to toxic substances and used successfully in acute static toxicity tests with complex wastes. M. bahia is recommended as a test species due to its sensitivity, short life-cycle, small size, and practical culture methods. Results from toxicity tests with mysids can be used to estimate the impact of ocean-dumped materials on other salt water crustaceans.

Acute, lethal effects of fenthion (an organophosphate insecticide) on mysids (Mysidopsis bahia), grass shrimp (Palaemonetes pugio), pink shrimp (Penaeus duorarum), and sheepshead minnows (Cyprinodon variegatus) were determined in laboratory tests and after field applications. Exposure at four field sites ranged from short-term exposures (12 h or less) of rapidly decreasing fenthion concentrations to extended intervals (more than 72 h) with slowly increasing or decreasing fenthion concentrations. Laboratory-derived LC50s provided a reliable benchmark for predicting acute, lethal effects of fenthion on caged animals in the field when exposures persisted for 24 h or more but overestimated the toxicity for exposures less than 24 h. Laboratory pulse-exposure tests with rapidly changing concentrations for 12 h were predictive of nonlethal and lethal effects observed for short-term field exposures.

Clark, James R., Larry R. Goodman, Patrick W. Borthwick, James M. Patrick, Jr., Geraldine M. Cripe, Paul H. Moody, James C. Moore and Emile M. Lores. 1989. Toxicity of Pyrethroids to Marine Invertebrates and Fish: A Literature Review and Test Results with Sediment-Sorbed Chemicals. EPA/600/J-89/040. Environ. Toxicol. Chem. 8(5):393-401. (ERL,GB 618). (Avail. from NTIS, Springfield, VA: PB90-103599)

Data on the acute and chronic toxicities of permethrin, cypermethrin and flucythrinate to marine invertebrates and fish are reviewed. Generally, crustaceans are more sensitive than fish; oysters are comparatively insensitive. The mysid Mysidopsis bahia consistently is among the most sensitive crustaceans tested, with 96-h LC50s of less than 0.02 µg/L for permethrin and of less than 0.01 µg/L for fenvalerate, cypermethrin and flucythrinate. The potential for chronic toxicity to fish is minimal for permethrin, moderate for fenvalerate and relatively great for flucythrinate. Laboratory toxicity tests were conducted with sediment-source fenvalerate and cypermethrin under static and flow-through conditions to determine the degree of contamination necessary to achieve acute lethal effects on mysids, grass shrimp (Palaemonetes pugio) and pink shrimp (Penaeus duorarum). Mortality was observed in test animals only in systems where the concentrations of sediment-source pyrethroids were sufficient to establish lethal concentrations in the overlying water through sediment/water partitioning. For fenvalerate, lethal effects occurred at nominal sediment concentrations of 0.1 mg/kg (static and flow-through) for mysids and grass shrimp and at 10 mg/kg for pink shrimp. Nominal sediment concentrations of cypermethrin of 0.1 mg/kg (static) or 0.1 mg/kg (flow-through) resulted in mortality in mysids and grass shrimp, whereas 1.0 mg/kg was the only test concentration that caused mortality in pink shrimp in the static and flow-through test systems. The correspondence between aqueous concentrations and LC50s for test animals demonstrated the importance of quantitating the bioavailable portion of pyrethroids in field samples to characterize accurately the environmental risk associated with pyrethroid runoff after agricultural applications.

Duke, Thomas W., Patrick W. Borthwick, Alan J. Rick and Michael D. Schmitt. 1970. Kinetics of Pesticides. In: U.S. Fish Wildl. Serv. Circ. 335. U.S. Dept. of the Interior, Washington, DC.. Pp. 33. (ERL,GB X444).

A former residence was renovated during the year to provide 1,600 square feet of air-conditioned laboratory space for work with radioactive materials. We installed a liquid scintillation spectrometer with three channels and automatic printout and added other equipment for tracer work, such as a lead vault and chemical hood. We have started experiments to study the rates at which plants and animals accumulate and excrete pesticides labelled with radioactive elements and the rates of movement of these chemicals through estuarine ecosystems. For example, DDT with labelled radioactive carbon was transferred through three trophic levels of a 'laboratory' food chain consisting of phytoplankton and two species of fish. Also, experiments are underway to determine the rate of movement of pesticides between water and sediments.