Continuous exposure to mercury during embryogenesis and chick development affects later survival and reproduction of zeb
- PDF / 631,881 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 59 Downloads / 205 Views
Continuous exposure to mercury during embryogenesis and chick development affects later survival and reproduction of zebra finch (Taeniopygia guttata) Cybele Heddle1 John E. Elliott1,2 Tanya M. Brown1 Margaret L. Eng1,3 Marie Perkins4,5 Niladri Basu4 Tony D. Williams1 ●
●
●
●
●
●
1234567890();,:
1234567890();,:
Accepted: 21 June 2019 © Springer Science+Business Media, LLC, part of Springer Nature 2019
Abstract Methylmercury (MeHg) is a global environmental contaminant that bioaccumulates and has multiple toxic modes of action. Aquatic species have traditionally been the focus of wildlife toxicological research on mercury, but terrestrial organisms, including passerine birds, can be exposed to similarly elevated levels of MeHg. In this study we exposed a model passerine, the zebra finch (Taeniopygia guttata), to MeHg in ovo, as chicks only, or with a combined ‘in ovo + chick’ treatment. We isolated exposure to specific developmental stages through the use of egg injections (3.2 µg Hg/g egg) and controlled oral dosing of chicks (0.24 µg Hg/g bw/day from day 1 to day 30). In ovo exposure to MeHg reduced hatching success, but there was no effect of MeHg on chick growth. We found that in ovo only or chick only exposure did not have long-term effects, but there was some evidence for longer-term effects of combined ‘in ovo + chick’ exposure on post-fledging survival and potentially sex-biased survival which resulted in very few ‘in ovo + chick’ exposed females surviving to breed. These females also had lower overall breeding productivity that was mainly due to lower hatching success of their offspring, not lower chick-rearing success. We found no effect of treatment on clutch size or latency to laying among females that did lay eggs. Our study suggests that combined embryonic and nestling MeHg exposure has compounding latent effects on productivity, likely through a mechanism that influences the ability of females to lay fertile eggs that hatch. Keywords Methylmercury Passerine Hatching success Survival Reproduction Courtship behaviour ●
●
●
●
●
Introduction
Supplementary information The online version of this article (https:// doi.org/10.1007/s10646-019-02074-6) contains supplementary material, which is available to authorised users. * John E. Elliott [email protected] 1
Biological Sciences, Simon Fraser University, Biological Sciences, Burnaby, BC V5A 1S6, Canada
2
Environment and Climate Change Canada, Ecotoxicology and Wildlife Health Directorate, Delta, BC V4K 3N2, Canada
3
Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada
4
Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, QC H9X 3V9, Canada
5
Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
Since the onset of industrialisation, both diffuse and pointsource emissions of mercury have contributed to a two to three-fold increase in the levels detected in the atmosphere, soil and water (Gobeil et al. 1999; Driscoll et al. 201
Data Loading...
