Florida Atlantic: Uncovering A New Subspecies

Alaska’s largest freshwater lake is home to a remarkable and genetically distinct population of harbor seals. Unlike their marine counterparts, these seals have adapted to live year-round in a freshwater habitat. A new study, led by Florida Atlantic University researchers in collaboration with Indigenous communities and other partners, has revealed that these seals are genetically isolated from nearby marine populations.

Published in Biology Letters, the research highlights that these seals are evolutionarily, reproductively and demographically separate from other Pacific harbor seal populations. Genetic analysis of samples, including scat collected from their habitat in Iliamna Lake, showed significant differences between the lake seals and marine populations across Alaska, Russia and California. These findings suggest the Iliamna Lake seals may represent a unique subspecies of harbor seals.

“Our findings are both striking and unexpected,” said Greg O’Corry Crowe, Ph.D., senior author, program lead, and a research professor at Florida Atlantic’s Harbor Branch Oceanographic Institute. “Indigenous knowledge and early Russian explorers’ accounts suggest that the seals have been in Iliamna Lake for at least 200 years. However, it’s still uncertain whether they have been there for a longer period or if the observed differences might indicate that the Iliamna seals represent a separate subspecies, similar to other freshwater seal populations.”

Unlike most harbor seals, the Iliamna seals exhibit unique adaptations to freshwater living, a rare phenomenon among seals worldwide.

Despite their genetic isolation, the seals face increasing challenges. Mining exploration in the region raises concerns about potential impacts on Iliamna Lake’s delicate ecosystem. The research team hopes their findings will guide conservation and co-management strategies to protect this population.

The team plans additional genomic studies to deepen insights into the seals’ evolution and adaptability. Collaborating closely with local communities and NOAA, they aim to balance conservation efforts with sustainable management of the lake’s resources.

As research continues, the Iliamna Lake seals stand as a testament to nature’s resilience and adaptability in one of Alaska’s most remote regions.