Concentrations of legacy persistent organic pollutants and naturally produced MeO-PBDEs in dugongs (Dugong dugon) from Moreton Bay, Australia

Abstract

Dugongs (Dugong dugon) are an iconic and strictly herbivorous species. They inhabit coastal areas, which brings them in contact with urban and agricultural pollutant sources, yet their exposure and susceptibility to environmental pollutants is still largely unknown. The goal of this study was to investigate the presence of several legacy compounds such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and pesticides as well as naturally produced MeO-PBDEs in male and female dugongs from Moreton Bay (n = 24), a semi-enclosed embayment close to Australia's third largest city, Brisbane. Results show that concentrations of all investigated compounds are low in general (< 120 ng/g lipid weight)and below known toxicity thresholds established for marine mammals. However, concentrations found in this study are higher or comparable to concentrations in dugongs outside Moreton Bay or in sirenians worldwide. No temporal trends for POPs from 2001 until 2012 were found for adult animals suggesting that environmental changes are only slowly reflected in dugongs. Finally, pollutant profiles in dugongs are limited to the most persistent PCBs, pesticides and PBDEs that also dominate POP profiles in other marine mammal species in general.

First assessment of POPs and cytochrome P450 expression in Cuvier’s beaked whales (Ziphius cavirostris) skin biopsies from the Mediterranean Sea

“…This congener distribution and abundance also reflects the high deep-sea sediment and organisms’ affinity towards higher chlorinated congeners relative to that of low chlorinated compounds, suggesting the ease for the former to be transported from surface waters to the deep-sea 44 . However, the same trend was also observed in other beaked whales 34 , 60 and marine mammals in general 46 , 62 , 74 – 76 , since these compounds are non biotransformable in cetaceans 41 , 77 , 78 . The abundance profile of non- ortho -dl-PCBs in the study samples (77 ≈ 126 > 169 > 81) is similar to other beaked whales 56 , 57 but is remarkably different from that reported in blubber from Mediterranean sperm whales (126 > 169 > 77 > 81 65 ).…”

Concentrations of some legacy pollutants have increased in South Australian bottlenose dolphins from 1989 to 2014

“…In all samples, except for the kidney of one adult female from the YII cohort, 2'-MeO-BDE 68 levels were higher compared to those of 6-MeO-BDE 47. This pattern is considered common for marine mammals from the southern hemisphere (Melcher et al, 2005;Dorneles et al 2010;Weijs et al, 2019) although a predominance of 6-MeO-BDE 47 has been reported previously in long-finned pilot whales from Tasmania (Weijs et al, 2013). Our results show that age, gender and year do not influence MeO-PBDE levels significantly in blubber, muscle, kidney or liver, which is probably due to the high degree of variability within each group, the lack of true mother/offspring pairs in either cohort and the knowledge that maternal offloading of MeO-PBDEs is limited as suggested previously (Weijs et al, 2019) (Table 1).…”

“…neonates, juveniles) and adult females. HCB and HCHs have recently been shown to preferentially accumulate in tissues other than blubber in dugongs because of their lower log Kow values compared to PCBs, DDXs and PBDEs (Weijs et al, 2019). Gestation and lactation are responsible for developing a blubber layer in young animals and cause a re-mobilisation of POPs that are present in the blubber of mothers (Debier et al, 2003;Brown et al, 2016).…”

“…These compounds are produced naturally by algae and sponges, which makes them different from the other compounds analysed in the study. Nevertheless, they have also been linked to adverse effects in wildlife and have already been detected at considerable levels in Australian marine mammals (Vetter et al, 2001;Weijs et al, 2019). The specific aims of this study were to 1) investigate the different POPs and MeO-PBDEs in several tissues of Tursiops aduncus from all ages and both genders, 2) assess how the pollutants are distributed across different tissue types (liver, muscle, kidney and blubber), 3) explore potential temporal trends between dolphins collected during 1989-1995 and dolphins from 2009-2014, 4) examine whether there are differences in pollutant levels between animals with different health status (e.g., cetacean morbillivirus), and 5) compare the results to levels and toxicity thresholds reported for marine mammals in the literature.…”

Calculation and Experimental Validation of a Novel Approach Using Solubility Parameters as Indicators for the Extraction of Additives in Plastics

“…are widely used to improve the properties of products . Many additives can be released during the use and subsequent treatment of plastics waste, which has adverse impacts on the environment and human health. − For example, brominated flame retardants, as plastic additives, have been globally recognized as environmental pollutants. − Accurate quantitative analysis of additives in plastic products is crucial for the study of their migration and human exposure estimation.…”