Climate change is a major issue, especially in the Arctic as sea ice retreats. Now, scientists have found that polar bears are swimming more and more as sea ice retreats and they search for food.
In this latest study, the researchers took a look at the swimming behavior of polar bears. More specifically, they looked at how much polar bears were swimming and how that may have changed over time.
"Recent studies indicate that swimming may be energetically costly to polar bears," said Nicholas Pilfold, a postdoctoral fellow at San Diego Zoo Global who was involved in this latest study. "Given the continued trend of sea ice loss, we recognize that an increased frequency in the need to engage in this behavior may have serious implications for populations of polar bears living around the Arctic Basin."
In this latest study, the researchers examined satellite-linked telemetry-tracked populations of polar bears in the Beaufort Sea and Hudson Bay. The researchers found that there's increased swimming associated with reduced ice due to climate change. In fact, during 2012, when the Arctic sea ice hit a record low, a total of 69 percent of the tracked adult females in the Beaufort Sea area swam more than 31 miles at least once.
The researchers also found that swims occurred more frequently in the Beaufort Sea than in Hudson Bay. In addition, females with young cubs swam less in order to avoid submerging young bears in cold waters. However, lone subadults swam as frequently as lone adults. In all, the longest recorded swim was from a subadult female that traveled over 249 miles over the course of nine days.
These results, in particular, highlight the fact that polar bears are swimming more often. This can be detrimental to their health, and can cause them to be less likely to survive as less and less sea ice is available each year.
"The pattern of long-distance swimming by polar bears in the Beaufort Sea shows the fingerprint of climate change," Pilfold said. "Swims are occurring more often, in association with sea ice melting faster and moving farther from shore in the summer."
The findings were published in the April 14 issue of the journal Ecography.
