“Glacial Changes Impact Harbor Seals’ Frozen Habitat: New Research Reveals Surprising Findings”

The research conducted by Lynn Kaluzienski and her team sheds light on the intricate relationship between harbor seals and icebergs in icy regions. The study, which will be presented at AGU’s 2024 Annual Meeting, focuses on how changes in glaciers due to climate change impact the availability of icebergs for seals in Johns Hopkins Inlet and Glacier in Glacier Bay National Park, Alaska.

Johns Hopkins Glacier is unique in that it is one of the few glaciers on Earth that is advancing rather than retreating. This is attributed to its terminal moraine, which acts as a barrier against warmer ocean water that would otherwise increase the glacier’s melt rate. However, this also means that fewer icebergs are shed into the fjord, reducing the habitat available for seals.

To understand how seals utilize the icebergs in the fjord, the researchers used time-lapse cameras and aerial surveys to track the distribution of seals and icebergs. They found that during the pupping season in June, mother seals preferred slower-moving icebergs for giving birth and caring for pups. In contrast, during the molting season in August, seals were more likely to be found on faster-moving icebergs near the plume of freshwater runoff from the glacier.

The plume of freshwater runoff brings plankton and fish to the surface, creating a feeding ground for seals. The researchers discovered that seals were more likely to be found on icebergs near the plume during the molting season, indicating that these icebergs offer better foraging opportunities.

Overall, the study highlights the importance of understanding how climate change affects glacier dynamics and, in turn, impacts the habitat and behavior of harbor seals in icy regions. By studying the relationship between glaciers, icebergs, and seals, researchers can better predict how these ecosystems will respond to future changes in climate.