3-year PhD project “Effects of contaminants, environmental conditions and intestinal microbiota on the behaviour of Arctic seabirds”
Context
Since the end of the 19th century, the development of human activities on a global scale has led to a rapid increase in emissions of chemical contaminants into the environment. Despite international conventions such as the Minamata Convention on mercury and the Stockholm Convention on POPs, which aim to regulate these emissions, environmental concentrations of many contaminants are still increasing. The presence of these contaminants in ecosystems is a major source of concern as some of them, such as heavy metals and persistent organic pollutants (POPs), can be highly toxic, sometimes at very low concentrations, with impacts on organisms, species and ecosystems. In this context, it is important to understand both the dynamics of contaminants in food webs and their impacts on the biodiversity.
Although free from intensive industrialization and far from the main sources of pollution, large quantities of pollutants emitted by northern countries of the north hemisphere are transported and deposited in the Arctic every year, which is thus threatened by a major and growing risk of pollution. This risk adds to other major environmental changes in this region (e.g. rising temperatures, melting ice, etc.), all of which represent additional stressors likely to impact (alone or in combination with chemical contaminants) organisms, populations and, ultimately, the entire biodiversity and ecosystems of the Arctic. The Arctic is therefore an essential region for assessing and understanding the impact of environmental changes, and in particular environmental contamination, on marine and coastal organisms and ecosystems.
Among Arctic organisms, top predators, and seabirds in particular, are the most exposed to this environmental contamination due to their position at the top of the food chain. Moreover, seabirds play an essential role in the functioning of their ecosystems but are among the organisms most impacted by changes in their environment. A better understanding of the impact of environmental changes on these species is therefore crucial.
This PhD project will therefore aim to further investigate the impacts of environmental contamination and other environmental stressors on Arctic seabirds. To this end, it will focus on a contaminant of high environmental concern in the Arctic: mercury, and on two major populations of little auks (Alle alle) breeding in East Greenland and in Spitsbergen, exposed to contrasting contaminations and environments. These two populations are monitored annually as part of two long-term programs coordinated by the two co-supervisors. Furthermore, the project will examine the role of intestinal microbiota at the interface of bird contamination and health.
Objectives
1/ Study the effects of mercury on little auk parental care
As part of the two long term research programs at Kap Hoegh (East Greenland) and Hornsund (Spitsbergen), various data have previously been collected and will be used: 1/ accelerometer data which allow to study the behavior and foraging effort of adult birds, such as time spent at sea, time spent diving, frequency of chick feeding, 2/ video data to better understand the nesting behavior of pairs of parents and the coordination between the two partners, 3/ biologging data (light level sensors) to infer the time spent by the birds (both parents) at the nest. In addition to these data, diet samples (composition of prey brought back by parents to their chicks) have been collected. Finally, blood samples from the parents were collected to assess their contamination to mercury and ecophysiological condition, as well as their trophic status. Further data and samples will be collected as part of field programs funded at both sites by the French Polar Institute and the University of Gdańsk. The combination of all these data will enable to test the hypothesis that contamination of adult birds impacts their parental care.
2/ Evaluate the effects of mercury on the condition of chicks (in relation to parents’ contamination and impacts on their parental care)
Following the results obtained in the first part, the effects on chicks of a change in parental care and parental contamination will then be analyzed. More specifically, blood samples have been or will be collected from the chicks for which parents have been or will be monitored. These will be used to assess various ecophysiological parameters indicative of chick health (blood chemistry, telomere size, stress levels inferred from corticosterone, etc.). Chick growth rates have also been (or will be) monitored, along with fledging success. All these parameters will be compared with the contamination of these chicks (mercury but also selenium, which is known to play a role in mercury detoxification) and the care/contamination of their parents (part 1) to study the impact of parental contamination and care on the chicks. Contaminant analyses will also be carried out on eggshells from monitored nests (already collected) to differentiate the impact of parental care/contamination from that of embryonic development (pre-hatching) via mercury excretion into the egg by the female.
3/ Evaluate the role of intestinal microbiota as a modulator of mercury effects or as having a direct impact on birds
In recent years, it has been demonstrated that the intestinal microbiota plays a major role in the health of its host and its response to environmental contamination, particularly mercury. Feces have been collected every year since 2020 from adult and chick little auks from Greenland and Spitsbergen, some of which correspond to the individuals monitored in the first two parts. New samples will also be collected. These samples will be analyzed for microbiological diversity. Combined with the behavioral, ecotoxicological and ecophysiological data described above, results obtained will make it possible to study at these two sites 1/ the link between intestinal microbiota diversity and bird contamination, 2/ the link between the diversity of the intestinal microbiota of individuals (adults and chicks), their behavior and their ecophysiological condition (directly or indirectly via a microbiota/mercury interaction) at the individual scale, 3/ the link between the intestinal microbiota of different members of a family (adults and their chicks).
The PhD student will therefore be expected to:
– Participate to the collection of samples and data during one or two field seasons (1 in Spitsbergen and/or 1 in Greenland)
– Prepare and analyse samples for mercury and selenium concentrations
– Prepare feces samples for their analysis by the University of Łódź
– Perform telemore analyses
– Analyse behavioural data obtained from data loggers or video recordings
– Run statistical analyses on obtained results
– Supervise 1 master student during the course of the PhD
– Participate to one or two international conferences to present the PhD results
– Write several articles to be published in international scientific journals
This 3-year PhD project will start on October 1st, 2024. The PhD student will be based for most of the time at the LIENSs laboratory (http://lienss.univ-larochelle.fr/?lang=en) in La Rochelle, France, but will also spend visiting periods of several months in the Polar Ecology Group (https://polarecologygroup.wordpress.com), University of Gdańsk, Poland.
The PhD student will be co-supervised by Dr Jérôme Fort and Dr. Katarzyna Wojczulanis-Jakubas, and will work in close collaboration with researchers from various French, Polish and international institutes.
Funding for this PhD project is secured through a PhD grant from the University of La Rochelle and different ongoing research projects.
To apply, please send your CV and a cover letter to Jérôme Fort (jerome.fort@univ-lr.fr) and Katarzyna Wojczulanis-Jakubas (katarzyna.wojczulanis-jakubas@ug.edu.pl). Deadline for application is May 17. Interviews of selected candidates will take second half of May or first of June.
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