U of R research into the recovery of mercury-contaminated fish populations published in leading research journal Nature

News Release Release Date: December 15, 2021 9:00 a.m.

Dr. Britt Hall, a University of Regina biology professor, is part of a group of researchers whose paper on the recovery of mercury-contaminated fish populations was published today in Nature. Dr. Hall was part of the 15-year study which found that reducing mercury pollution entering lakes lowers how much harmful mercury is found in freshwater fish that are destined for consumers’ plates.

Dr. Hall’s uncle, Dr. John Rudd and aunt, Dr. Carol Kelly (also mercury biogeochemists) were part of the team that initiated this research project. After being involved with the project for the past 15 years, Dr. Hall has now seen the project come full circle with the group’s research paper being published in the world’s leading research journal.

During the study, scientists added a traceable form of mercury to a lake and surrounding forests and wetlands at the IISD Experimental Lakes Area in Ontario. They discovered that the new mercury added quickly built up in fish populations, and then declined almost as quickly once additions stopped. The mercury concentrations in the fish populations recovered much quicker than previously understood, suggesting that curbing mercury pollution through policy initiatives will have rapid and tangible benefits regarding the quality of fish we consume.

“Technologies that can remove mercury from emissions are available and relatively straightforward. However, they do add expense to operations,” says Dr. Hall. “The Mercury Experiment to Assess Atmospheric Loading in Canada and the United States (or METAALICUS) showed that if society chooses to prevent Hg emissions, toxic mercury in fish will decline. It was a great honour and pleasure to be part of this experiment.”

The IISD Experimental Lakes Area is one of the only facilities in the world where lakes and their watersheds can be experimentally manipulated to determine the many ways in which humans are impacting lakes. The METAALICUS team applied about one teaspoon of a special form of mercury to a lake and its watershed. As new mercury inputs to the experimental lake were increased and then decreased in a controlled manner, the methylmercury in the lake water, surface sediments, invertebrates, and fish both increased and decreased quickly. Methylmercury is a much more toxic form of mercury that accumulates to high concentrations in many freshwater fish leading to many adverse, and even life-threatening, symptoms in humans. The decline occurred whether the mercury ‘rained’ directly onto the lake surface or entered the lake from the surrounding watershed in streams.

The findings provide indisputable, science-based support for necessary regulations on mercury emissions that have been undermined in recent years, especially in the USA. In addition, the findings support the efficacy of existing and new policies around the globe that seek to curb the amount of mercury that ends up in our environment. 

“Dr. Hall’s contribution to this important paper demonstrated that University of Regina research make a difference in the world,” says Dr. Kathleen McNutt, Vice-President (Research). “Our scientists provide solutions to globally important issues in real-world settings.”

Nature is a weekly international journal publishing the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature also provides rapid, authoritative, insightful and arresting news and interpretation of topical and coming trends affecting science, scientists and the wider public. Read the full Experimental evidence for recovery of mercury-contaminated fish populations paper here: https://www.nature.com/articles/s41586-021-04222-7


About the University of Regina

The University of Regina—with campuses located on Treaty 4 and Treaty 6 territories, the ancestral lands of the Cree, Saulteaux, Dakota, Lakota and Nakoda nations and the homeland of the Métis—is a comprehensive, mid-sized university that traces its roots back to the creation of Regina College in 1911. Today, more than 16,000 students study within the University's 10 faculties, 25 academic departments/schools, 18 research centres and institutes, and three federated colleges (Campion College, First Nations University of Canada, and Luther College). The University of Regina has an established reputation for excellence and innovative programs that lead to undergraduate, master’s, and doctoral degrees.


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