|Abstract Title:||Finding the Source of Selenonein in the Arctic Food Web: Quantification of the Benthic Environment in Nunavik and the Eastern Arctic|
|Presenter Name:||Ariane Barrette|
|Session:||Special Session - Selenium-mercury interactions in aquatic food webs: The state of the science and future research directions|
Abstract Information :
Selenonein, an antioxidant analogous to ergothioneine where sulfur is replace by selenium, is believed to positively affect contaminant Methyl mercury (MeHg) through a demethylation process that could be linked with its detoxification. It could be particularly beneficial for Inuit populations of Nunavik who are at high risk of chronic exposure to MeHg. However, only specific types of bacteria can synthesize selenonein, so the question remains as to where organisms acquire this molecule in the food web. The literature suggests the benthic environment could have high concentrations of this element since many benthic organisms have shown high concentrations of selenium, an essential component of selenonein. Also, organisms in contact with the seafloor, such as belugas, a significant source of selenonein among Nunavik Inuit, have higher concentrations of selenonein than more pelagic organisms of similar trophic levels such as ringed seals. This project is a joint initiative of Sentinel North and the Institut Nordique du Qubec. The objective is to quantify selenonein in the benthos of Nunavik by comparing the selenonein concentrations of different benthic organisms, macroalgae, and sediment at different study sites in the Northeastern Canadian Arctic. Depending on how selenonein is acquired by organisms, either by feeding or friction, benthic organisms or sediment are expected to have higher selenonein levels based on the dominant hypothesis. Samples for this project were collected onboard the research vessel CCGS Amundsen using benthic trawls and box corers, while others were collected by hand from coastal areas in collaboration with local communities. Selenonein will be quantified using liquid chromatography and mass spectrometry (LC-MS-MS). Identifying the source of selenonein and how it is acquired in the Arctic food web could help protect against the harmful effects of MeHg and reinforce the idea of the importance of preserving Inuit culture through traditional harvesting practices.