A new study by Dr. Gretchen Roffler and colleagues reveals a surprising consequence of adaptation: coastal Alaskan wolves that shifted their diet from deer to sea otters now carry some of the highest mercury levels ever recorded in land predators. On Pleasant Island near Glacier Bay National Park, the local wolf pack now preys heavily on sea otters — a rare case of a terrestrial apex predator hunting a marine apex predator. This dietary shift allowed the wolves to survive despite a decline in terrestrial prey but exposed them to mercury contamination through the marine food web.
In this circumstance, the human-driven increase in atmospheric mercury intersected with sea otter recovery to create a new pathway for contamination, perfectly exemplifying the complicated consequences of human actions – even in remote and wild places. The mercury levels found in Pleasant Island wolves are actually similar to those typically observed in polar bears, one of the animals most exposed to this contaminant. Some wolves were found to have tissue mercury levels associated with severe to high health risks.
This research highlights the complex interactions between conservation efforts, climate change, and pollution. It also calls attention to the need for ecosystem-level thinking and research to better understand and manage the far-reaching impacts of human actions, even in the most remote environments, for which K9 detection dogs can be an invaluable resource.
Read the full paper here: https://www.sciencedirect.com/science/article/pii/S0048969725011830