Arctic seals face a dual threat from climate change and persistent contaminants, according to a study by Simon Fraser University (SFU). The research reveals that a single year of warmer-than-average Arctic temperatures can lead to malnutrition in these seals, exacerbating the risks to Inuit food security and the already-strained northern ecosystems. The study, published in Environmental Research, analyzed blood, blubber, and liver samples from 38 Arctic ringed seals in Labrador's Saglek Bay and adjacent fjords from 2009 to 2011. The findings indicate that these seals are struggling to eliminate persistent contaminants and banned pesticides from their bodies, a long-term health risk that is further compounded by climate-driven changes to sea ice and temperatures, limiting their access to nutrient-rich food. The research highlights that warmer conditions can alter the seals' diet, which in turn changes their exposure to contaminants, potentially impacting their overall health and survival. The study also found consistently high levels of PCBs, mercury, DDTs, and chlordane in the liver samples across all three years. These contaminants, some of which are internationally banned, are known to cause oxidative stress, a form of cellular damage linked to inflammation, chronic disease, tissue injury, and reduced reproductive health. Furthermore, blood and blubber samples taken in 2010, an unusually warm year with low Arctic sea ice, showed signs of malnutrition, including a thinner blubber layer and depleted fatty acids. The study's lead author, Anaïs Remili, emphasizes that just one year of such conditions can significantly impact the seals' diet and nutrient processing. The persistence of contaminants like PCBs, DDTs, and chlordane in Arctic ecosystems for decades, due to their slow breakdown and long-range travel, poses a significant threat. These substances are lipophilic, meaning they are stored in the blubber of marine mammals like seals. Remili explains that thinner, nutritionally stressed seals redistribute these contaminants from their blubber back into the bloodstream, affecting their entire system. While the seals generally rebounded from malnutrition in 2011, the study warns that future nutritional stress could exacerbate the long-term damage caused by oxidative stress. The rapid sea-ice loss and shifting marine food webs are already altering the seals' diet and habitat. Climate-driven changes in ocean currents could further introduce more global pollutants into Arctic regions, posing additional risks to the seals and the local communities that depend on them. The study underscores the importance of healthy seal populations for both food security and cultural continuity in these regions.
