Arctic Warming Opens Waters To More Whales, Increasing Food Competition
Rapid sea ice loss in the Arctic is opening new waters to humpback and fin whales, a new study revealed. While these marine animals used to visit the far north only during the summer, warming waters are causing sea ice to retreat at an increasing rate. This may increase food competition among bowhead whales that once had this region to themselves.
For their study, researchers from the National Oceanic and Atmospheric Administration (NOAA) Fisheries West Coast Region used hydrophone surveys in order to better understand how marine species respond to climate change.
"We see winners and losers as changes accelerate, and some of the winners are likely to be those that are most adaptable and resilient to change," Sue Moore, a senior scientist at NOAA Fisheries, explained in a news release.
Marine mammals reflect the impacts of climate change through changes not only in their diet and physical condition, but through shifts in their range and habitat. Researchers say climate change is likely to invite many other species into new habitats. Their study was recently presented at the Society of Marine Mammalogy's Biennial Conference in San Francisco.
One of the ways researchers can assess the impacts of climate change is by evaluating shifts in feeding strategies of marine animals, which they are able to do by measuring the stable isotopes present in their bones. This revealed that walrus are among the many that reflect a shift in prey sources as a result of past climate changes.
"Over 4,000 years they [walrus] appear to have covered a whole gamut of different prey items and prey locations," Casey Clark of the University of Alaska Fairbanks explained. "They have changed their diet, very likely in response to environmental changes. Maybe this kind of generalism will help them in being able to transition to different prey items, but that remains to be seen."
Other research presented at the conference links rapid sea ice loss, Arctic warming, and weather tendencies, shedding light on how this trifecta may impact species around the world.
"It's not simple, but as Mother Nature keeps dishing out these unusual events we can start to connect the dots between them to understand the larger picture of what's happening and how it's likely to affect animals within and beyond the Arctic, including humans," Jennifer Francis, a Rutgers University research professor and a plenary speaker at the conference, said.
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