Search USGSSearch

USGS · 70177037

Accumulation of 2,3,7,8-Tetrachlorodibenzo-p-dioxin equivalents by double-crested cormorant ( Phalacrocorax auritus , Pelicaniformes) chicks in the North American Great Lakes

Abstract

Concentrations of polychlorinated biphenyls (PCBs), and 2,3,7,8-tetrachlordibenzo- p -dioxin equivalents (TCDD-EQ) were determined in eggs and chicks of double-crested cormorants (DCC) which were collected in 1989 from eight locations in the Laurentian Great Lakes. The mean biomagnification factor (BMF) from forage fish to eggs was found to be 31.3. Absolute and relative concentrations as well as rates of accumulation of total concentrations of PCBs and TCDD-EQ were measurable in all of the samples. The concentrations of both PCBs and TCDD-EQs decreased immediately upon hatching of chicks, due to growth dilution. Initial decreases in absolute masses of TCDD-EQ in chicks were also observed, which indicates that there can be significant elimination of these compounds during early development. The initial rates of accumulation by chicks were dependent only on the mass of fish consumed. After the chicks began thermoregulating, the rates of accumulation, expressed as a concentration, normalized to body weight, became greater. Rates of accumulation of both PCBs and TCDD-EQ were correlated with their respective concentrations in forage fish consumed by the chicks. The relative potency, expressed as the ratio of the concentration of TCDD-EQ to that of total PCBs was calculated to determine if there was significant trophic-level enrichment of the TCDD-EQs, relative to total concentrations of PCBs. A significant enrichment was observed at the more and less contaminated locations, but the degree of enrichment was greater at the less contaminated locations (26 vs 72 μg/g).

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P. D. Jones, J. P. Giesy, J.L. Newsted, D. A. Verbrugge, J.P. Ludwig, M. E. Ludwig, H. J. Auman, R. Crawford, D. E. Tillitt, T.J. Kubiak, D. A. Best. 1994. Accumulation of 2,3,7,8-Tetrachlorodibenzo-p-dioxin equivalents by double-crested cormorant ( Phalacrocorax auritus , Pelicaniformes) chicks in the North American Great Lakes. https://doi.org/10.1006/eesa.1994.1016

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

The relative importance of mercury methylation and demethylation in rice paddy soil varies depending on the presence of rice plants

Neurotoxic methylmercury (MeHg) accumulates in rice grain from paddy soil, where its concentration is controlled by microbial mercury methylation and demethylation. Both up- and down-regulation of methylation is known to occur in the presence of rice plants in comparison to non-vegetated paddy soils; the influence of rice plant presence/absence on demethylation is unknown. To assess the concurrent influence of rice plant presence/absence on methylation and demethylation, and to determine which process was more dominant in controlling soil MeHg concentrations, we maintained six rhizoboxes of paddy soil with and without rice plants. At the peak of plant growth, we simultaneously measured ambient MeHg, ambient inorganic mercury (IHg), and potential rate constants of methylation and demethylation (K meth and K demeth ) in soil using stable isotope tracers and ID-GC-ICPMS. We also measured organic matter content, elemental S, and water-extractable sulfate. We found MeHg concentrations were differentially controlled by MeHg production and degradation processes, depending on whether plants were present. In non-vegetated boxes, MeHg concentration was controlled by K meth , as evidenced by a strong and positive correlation, while K demeth had no relation to MeHg concentration. These results indicate methylation was the dominant driver of MeHg concentration in non-vegetated soil. In vegetated boxes, K demeth strongly and negatively predicted MeHg concentration, indicating that demethylation was the dominant control in soil with plants. MeHg concentration, K meth , and % MeHg all had significantly less variance in vegetated than in non-vegetated soils due to a consistent elimination of greater values. This pattern suggests that reduced MeHg production capacity was a secondary control on MeHg concentrations in vegetated soils. We observed no difference in the magnitude or variance of K demeth between treatments, suggesting that demethylation was robust to soil chemical conditions influenced by the plant, perhaps because of a wider taxonomic diversity of demethylators. Our results suggest that methylation and demethylation processes could both be leveraged to alter MeHg concentrations in rice paddy soil.

Ecotoxicology and Environmental Safety

In ovo exposure to brominated flame retardants Part II: Assessment of effects of TBBPA-BDBPE and BTBPE on hatching success, morphometric and physiological endpoints in American kestrels

Tetrabromobisphenol A bis(2,3-dibromopropyl ether) (TBBPA-BDBPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTPBE) are both brominated flame retardants (BFRs) that have been detected in birds; however, their potential biological effects are largely unknown. We assessed the effects of embryonic exposure to TBBPA-BDBPE and BTBPE in a model avian predator, the American kestrel ( Falco sparverius ). Fertile eggs from a captive population of kestrels were injected on embryonic day 5 (ED5) with a vehicle control or one of three doses within the range of concentrations that have been detected in biota (nominal concentrations of 0, 10, 50 or 100 ng/g egg; measured concentrations 0, 3.0, 13.7 or 33.5 ng TBBPA-BDBPE/g egg and 0, 5.3, 26.8 or 58.1 ng BTBPE/g egg). Eggs were artificially incubated until hatching (ED28), at which point blood and tissues were collected to measure morphological and physiological endpoints, including organ somatic indices, circulating and glandular thyroid hormone concentrations, thyroid gland histology, hepatic deiodinase activity, and markers of oxidative stress. Neither compound had any effects on embryo survival through 90% of the incubation period or on hatching success, body mass, organ size, or oxidative stress of hatchlings. There was evidence of sex-specific effects in the thyroid system responses to the BTBPE exposures, with type 2 deiodinase (D2) activity decreasing at higher doses in female, but not in male hatchlings, suggesting that females may be more sensitive to BTBPE. However, there were no effects of TBBPA-BDBPE on the thyroid system in kestrels. For the BTPBE study, a subset of high-dose eggs was collected throughout the incubation period to measure changes in BTBPE concentrations. There was no decrease in BTBPE over the incubation period, suggesting that BTBPE is slowly metabolized by kestrel embryos throughout their ∼28-d development. These two compounds, therefore, do not appear to be particularly toxic to embryos of the American kestrel.

Ecotoxicology and Environmental Safety

In ovo exposure to brominated flame retardants Part I: Assessment of effects of TBBPA-BDBPE on survival, morphometric and physiological endpoints in zebra finches

Tetrabromobisphenol A bis(2,3-dibromopropyl) ether (TBBPA-BDBPE) is an additive flame retardant used in polyolefins and polymers. It has been detected in biota, including in avian eggs, yet little is known of its effects. We assessed the pattern of TBBPA-BDBPE concentrations in songbird eggs over the incubation period, and the effects of embryonic exposure to TBBPA-BDBPE in a model songbird species, the zebra finch (Taeniopygia guttata). To assess concentrations during embryo development, eggs were injected on the day they were laid with the vehicle control (safflower oil) or 100 ng TBBPA-BDBPE/g egg, and whole egg contents were collected throughout embryonic development on day 0 (unincubated), 5, 10 and 13. To evaluate effects of embryonic exposure to TBBPA-BDBPE, eggs were injected at Hamburger-Hamilton stage 18 (~80 hours after initiation of incubation) with safflower oil only, 10, 50 or 100 ng TBBPA-BDBPE/g egg (albumin injection volume 1 µl/g). Eggs were monitored for hatching success, and nestlings were monitored for growth and survival. At 15 days post-hatch, tissues were collected to assess physiological effects. TBBPA-BDBPE was incorporated into the egg as the embryo developed, and concentrations started declining in late incubation, suggesting biotransformation by the embryo. There were no effects on hatching success, nestling survival, growth, organ somatic indices, or thyroid hormone homeostasis; however, there was evidence that body condition declined in a dose-dependent manner towards the end of the rapid nestling growth phase. This decreased body condition could be a delayed effect of early developmental exposure, or it may be the result of increased exposure to biotransformation products of TBBPA-BDBPE produced over the nestling period, which are predicted to be more bioaccumulative and toxic than the parent compound.

Ecotoxicology and Environmental Safety