Larry R. Goodman

Kepone® bioconcentration, accumulation, loss, and transfer through estuarine food chains

Accumulation, transfer, and loss of Kepone in estuarine organisms were studied in laboratory bioassays. Kepone was bioconcentrated by oysters (Crassostrea virginica), mysids (Mysidopsis bahia), grass shrimp (Palaemonetes pugio), sheepshead minnows (Cyprinodon variegatus), and spot (Leiostomus xanthurus), from concentrations as low as 0.023 μg/l seawater. Bioconcentration factors ranged from 10 to 340 in static exposures and 900 to 13,500 in flow-through bioassays, and were dependent on species and exposure duration.

Diazinon(R): Chronic Toxicity to, and Brain Acetylcholinesterase Inhibition in, the Sheepshead Minnow, Cyprinodon variegatus

Abstract We investigated the toxicity of Diazinon to sheepshead minnows continuously exposed in flow-through toxicity tests. In the 96-hour acute test, a measured concentration of 1,400/ μg/liter was lethal to 50% of the juvenile test animals. In the partial life-cycle test, we also investigated uptake of Diazinon by sheepshead minnows and effect of Diazinon on brain acetylcholinesterase (AChE) activity. Average measured concentrations in the partial life-cycle test were nondetectable (control), 0.47, 0.98, 1.8, 3.5, and 6.5 μg of Diazinon per liter of seawater. Although the number of eggs spawned by continuously exposed fish was significantly reduced (α = 0.05) in all concentrations, no concentration tested significantly affected parental survival or fertility of eggs, nor were survival and growth of progeny affected in a subsequent 28-day test. Fish exposed to 0.47 μg/liter spawned 22.6 eggs/female-day, or 69% of control production (32.8 eggs/female-day). The number of eggs spawned by fish exposed to 6....

Kepone®: Chronic effects on embryo, fry, juvenile, and adult sheepshead minnows (Cyprinodon variegatus)

We investigated the toxicity of Kepone to, and uptake by embryo, fry, juvenile, and adult sheepshead minnows (Cyprinodon variegatus) using intermittent-flow toxicity tests. Concentration of Kepone and percentage of adult fish surviving in a 28-day exposure were: Control, 95%; 0.05 μg/liter, 95%; 0.16 μg/liter, 100%; 0.80 μ/liter, 78%; 1.9 μg/liter, 20%; and 7.8 μg/liter and 24 μg/liter, 0%. Concentration factors (concentrations in fish divided by concentrations measured in water) for adult fish averaged 5,200 (range 3,100 to 7,000). Symptoms of poisoning included scoliosis, darkening of the posterior one-third of the body, hemorrhaging near the brain and on the body, edema, fin-rot, uncoordinated swimming, and cessation of feeding. Adults surviving the first exposure were spawned, and the embryonic development, hatching, and survival and growth of fry and juveniles were monitored in a 36-day exposure to Kepone concentrations of 0.08, 0.18, 0.72, 2.0, 6.6, and 33 μg/liter. A significant number of embryos from adult fish exposed to 1.9 μg of Kepone/liter of water developed abnormally and died even when incubated in Kepone-free water. Kepone in water was not as lethal to progeny as to adults: 36-day LC50 for juveniles was 6.7μg/liter; 28-day LC50 for adults, 1.3 μg/liter. However, the average standard length of juvenile fish was significantly reduced by exposure to 0.08 μg of Kepone/liter of water; some fish developed scoliosis. Concentration factors in juvenile sheepshead minnows averaged 7,200 and increased from 3,600 to 20,000 as exposure concentrations decreased.

Effect of chronic exposure to EPN and to Guthion on the critical swimming speed and brain acetylcholinesterase activity of Cyprinodon variegatus

Abstract Swimming performance of the estuarine sheepshead minnow, Cyprinodon variegatus , was measured in a stamina tunnel at the end of life-cycle toxicity tests with the organophosphate pesticides EPN (265 days) and Guthion (219 days). Effects of acetylcholinesterase (AChE) inhibition were also determined. These measures were compared to survival, growth and reproduction data obtained in the life-cycle toxicity test. Significant effects on swimming stamina were detected in fish exposed to 2.2 μg EPN/1 (57% that of control fish) and in fish exposed to 4.1 μgEPN/1 (46% of controls). Survival and growth were reduced only in 7.9 μg EPN/1. Swimming performance was not affected by Guthion concentrations up to 0.5 μg/1, a concentration affecting reproduction. AChE was significantly inhibited by all tested concentrations of EPN, 0.25 to 7.9 μg/1, and Guthion, 0.06 to 0.50 μg/1. Swimming stamina may be an important endpoint to include with measurements of effects on survival, growth and reproduction in chronic toxicity tests with fish, but the relation of AChE inhibition to these endpoints is uncertain.

Multigenerational exposure of the estuarine sheepshead minnow (Cyprinodon variegatus) to 17β-estradiol. II. Population-level effects through two life cycles.

The evaluation of multigeneration, population-level impacts is particularly important in the risk assessment of endocrine-disrupting compounds, because adverse effects may not be evident during the first generation of exposure. Population models were developed for the sheepshead minnow (Cyprinodon variegatus) exposed to 17β-estradiol (E2) for two complete generations (F1 and F2) to determine population-level effects of multigenerational exposure to a model estrogen. Stage-structured matrix models were used to determine interactions between treatment and the number of generations exposed. Reproduction was significantly reduced in both the 0.08 and 0.2 μg E2/L treatments in both generations, and embryo and larval stages experienced reduced survival at 0.2 μg/L in the second generation only. However, increased female to male sex ratio in these treatments compensated for the loss in reproductive output, and significant population-level effects only occurred in the 0.2 μg E2/L treatment of the F2 population. The F2 population in the 0.2 μg E2/L treatment also had an altered, stable stage distribution relative to the control population of both generations and the Fl population in the 0.2 μg E2/L treatment, resulting in additional population-level effects. These results demonstrate that continued exposure to E2 had compounding effects on sheepshead minnow populations and that long-term exposures may be necessary to understand the risk that exposures to environmental estrogens pose to native populations. Although population-level effects did not occur in the Fl generation, a risk decision based on Fl organism-level effects would be protective of the population exposed for two generations.

Multigenerational exposure of the estuarine sheepshead minnow (Cyprinodon variegatus) to 17β-estradiol. I. Organism-level effects over three generations.

A 280-d study examined the effects of 17β-estradiol (E2) on reproduction and development of the sheepshead minnow (Cyprinodon variegatus) exposed from the parental (F0) through three subsequent (F1, F2, and F3) generations and evaluated the need for multigenerational assessments of the risks of endocrine-disrupting chemicals. This first three-generation study exposed adult F0 and F1 fish to measured concentrations of 0.01, 0.04, 0.08, 0.2, and 0.3 μg E2/L; the F2 and F3 generations were exposed to 0.2 μg E2/L or less. The cumulative 21-d production of normal embryos was significantly reduced in the F0 generation at 0.3 μg E2/L and in the F1 and F2 generations at 0.08 μg E2/L or more. The daily reproductive rate was significantly reduced in all three generations at 0.08 μg E2/L or more during spawning days 8 to 14 and 15 to 21. The proportion of infertile eggs from F1 fish was significantly increased above that of the solvent controls at 0.04 and 0.2 μg E2/L and from F2 fish at 0.04 μg E2/L or more. Changes in liver, kidney, and gonadal tissues were seen in the F0 and F1 generations exposed to 0.2 μg E2/L or more. The female gonadosomatic index was significantly decreased at 0.3 μg E2/L in the F0 and F1 generations. Estradiol affected the hepatosomatic index only in female F1 fish, but not in a dose-dependent manner. All F1 fish in 0.3 μg E2/L appeared to be phenotypically female. Our results indicate that life-cycle exposure to E2 significantly decreased embryo production by F1 and F2 fish at concentrations lower than those affecting the F0 generation, and they emphasize the importance of evaluating the impact of an estrogenic chemical on reproduction through a minimum of two (F0 and F1) generations.

A new early life-stage toxicity test using the California grunion (leuresthes tenuis) and results with chlorpyrifos☆

California grunion were continuously exposed as embryos and fry to technical chlorpyrifos in two toxicity tests conducted in the same exposure apparatus. The first test, a 35-day early life-stage (ELS) test, began with approximately 2.5-day-old embryos that were exposed in flow-through aquaria in darkness until hatching was stimulated on Day 9 of exposure. The second toxicity test, a fry test, began with newly hatched fry and lasted 26 days. Test water temperature ranged from 23 to 26 degrees C and salinity from 24.5 to 34.0%. Results of the two tests were similar, indicating that exposure of embryos added little to the overall toxicity of chlorpyrifos to grunions. Percentage hatch of embryos was unaffected by the chlorpyrifos concentrations tested. Fry survival was apparently reduced in nominal concentrations greater than or equal to 1.0 micrograms/liter in both tests, but significantly so in concentrations greater than or equal to 1.0 micrograms/liter in the ELS test and greater than or equal to 2.0 micrograms/liter in the fry test. When compared with carrier controls, mean fish weights were significantly reduced in nominal chlorpyrifos concentrations greater than or equal to 0.5 micrograms/liter in the ELS test and greater than or equal to 1.0 micrograms/liter in the fry exposure. Mean bioconcentration factors were 770X for fish that survived the ELS test and 190X for those that survived the fry test. Results demonstrate the practicality of conducting ELS tests for the first time with a marine fish from the Pacific coastal waters of the United States.

Exposure of three generations of the estuarine sheepshead minnow (Cyprinodon variegatus) to the androgen, 17β‐trenbolone: Effects on survival, development, and reproduction

Estimating long-term effects of endocrine-disrupting chemicals on a species is important to assessing the overall risk to the populations. The present study reports the results of a 42-week exposure of estuarine sheepshead minnows (Cyprinodon variegatus) to the androgen, 17beta-trenbolone (Tb) conducted to determine if partial-(F0) or single-generation (F1) fish exposures identify multigenerational (F0-F3) effects of androgens on fish. Adult F0 fish were exposed to 0.007, 0.027, 0.13, 0.87,and 4.1 microg Tb/L, the F1 generation to < or =0.87 microg Tb/L, the F2 fish to < or =0.13 microg Tb/L, and the F3 fish to < or =0.027 microg Tb/L. The highest concentrations with reproducing populations at the end of the F0, F1, and F2 generations were 4.1, 0.87, and 0.027 microg Tb/L, respectively. Reproduction in the F0, F1, and F2 generations was significantly reduced at 0.87, 0.027, and 0.027 microg Tb/L, respectively. Fish were significantly masculinized in the F1 generation exposed to 0.13 microg Tb/L or greater. Female plasma vitellogenin was significantly reduced in F0 fish exposed to > or =0.87 microg Tb/L. Gonadosomatic indices of the F0 and F1 generations were significantly increased at 0.87 and 0.13 microg Tb/L in the F0 and F1 generation, respectively, and were accompanied by ovarian histological changes. Reproduction was the most consistently sensitive measure of androgen effects and, after a life-cycle exposure, the daily reproductive rate predicted concentrations affecting successive generations. The present study provides evidence that a multiple generation exposure of fish to some endocrine-disrupting chemicals can result in developmental and reproductive changes that have a much greater impact on the success of a species than was indicated from shorter term exposures.

THE EFFECTS OF URBANIZATION ON THE CHEMICAL QUALITY OF THREE TIDAL BAYOUS IN THE GULF OF MEXICO

Water and sediment quality in threetidal bayous located near Pensacola, Florida, wereassessed during 1993–1995. The primary objective wasto determine the environmental condition of therelatively small urban bayous by comparing thechemical quality of the sediments and surface waterwith published guidelines and criteria developed toprotect marine life. Surface water concentrations ofmost potential toxicants such as heavy metals,organochloride pesticides, PAHs and PCBs were usuallybelow method detection limits. The major exception tothis trend was for copper which consistently exceededFlorida and National acute and chronic water qualitycriteria. Nickel, cadmium and chromium intermittentlyexceeded these criteria. Sediment contamination wassite-specific and chemically diverse. Theconcentrations of as many as 17 compounds exceededproposed Florida sediment quality assessmentguidelines indicating the potential for adversebiological effects. Nutrient concentrations, with oneexception, were below average levels found in otherFlorida estuaries. Seasonal variation in contaminantconcentrations for sediment collected from the samesampling station was less than an order of magnitude. The differences in the concentrations of the sameanalytes as measured for the multiple samplingstations located within the same bayou varied 1 to 2orders of magnitude and over 2 orders of magnitude forthe 20 sampling stations located in the three bayous. A within-bayou sediment contaminant gradient wasevident; sediment quality generally improved seaward.

Comparison of estrogen-responsive plasma protein biomarkers and reproductive endpoints in sheepshead minnows exposed to 17β-trenbolone

Protein profiling can be used for detection of biomarkers that can be applied diagnostically to screen chemicals for endocrine modifying activity. In previous studies, mass spectral analysis revealed four peptides (2950.5, 2972.5, 3003.4, 3025.5m/z) in the plasma of estrogen agonist-treated male and gravid female sheepshead minnows (Cyprinodon variegatus, SHM), which served as distinct estrogenic biomarkers. In this study, a 21-day reproductive assay with adult SHM was conducted to investigate possible dose-related effects of the synthetic androgen, 17beta-trenbolone, on expression of these four estrogen-responsive peptides. In addition, the response of the peptide biomarkers were compared to traditional reproductive endpoints of fecundity, histopathology, secondary sex characteristics, length, weight, hepatosomatic index, female gonadosomatic index and plasma vitellogenin (VTG) levels. Fish were continuously exposed to 0.005, 0.05, and 5.0 microg/l, a solvent control (triethylene glycol, TEG), and a seawater control (SW) using an intermittent flow-through dosing system. Plasma was analyzed for the presence of the four peptide biomarkers by MALDI-TOF MS and VTG protein by quantitative ELISA. Male fish from the trenbolone treatments and controls showed no expression of the four peptide biomarkers or measurable levels of VTG. The estrogen-responsive biomarkers and plasma VTG were constitutively expressed in females from the SW, TEG, 0.005 and 0.05 microg/l exposures. All four peptide biomarkers were significantly reduced (p<0.0002 to p<0.005) at the 5.0 microg/l treatment level which corresponded with significant reductions in fecundity and changes in ovarian morphology. A distinct but non-significant reduction in VTG was also observed in female fish from the 5.0 microg/l treatment. Results of this study suggest application of these estrogen-responsive protein biomarkers may be a cost effective alternative to fecundity measures which are labor intensive and expensive to conduct.