Why Are Puffins and Other Seabirds Dying in the Bering Sea?
The Bering Sea is home to a diverse population of seabirds, including puffins, crested auklets, horned puffins, and murres. In 2016, a mass die-off of seabirds occurred in the eastern Bering Sea, with an estimated 3,150 to 8,800 birds perishing.
Cause of the Die-Off
A new study published in PLOS One suggests that climate change is at least partly responsible for the die-off. The study found that warming waters and a reduction of ice in the Bering Sea have led to a decline in cold-water plankton, which are a major food source for seabirds.
Signs and Symptoms of Seabird Starvation
The seabirds that died in the 2016 die-off were severely emaciated, indicating that they had died of starvation. Other signs and symptoms of seabird starvation include:
- Lethargy
- Weakness
- Loss of appetite
- Weight loss
- Dull feathers
- Disorientation
Why Are Tufted Puffins Molting Late?
Tufted puffins typically molt between August and October, once they have already migrated to winter foraging grounds. However, the tufted puffins that died in the 2016 die-off were in mid-molt when they washed ashore in October, suggesting that they had been molting late.
Molting is a stressful period for birds because it increases their energy needs but also reduces their ability to fly and dive, making it difficult to find food. The tufted puffins that died in the 2016 die-off may have been molting late because they were unable to find enough food to sustain themselves during this vulnerable period.
How Does the Availability and Quality of Prey Affect Seabird Survival?
Seabirds rely on a variety of prey species, including fish, plankton, and krill. The availability and quality of these prey species can have a significant impact on seabird survival.
In the Bering Sea, cold-water plankton are a major food source for seabirds. However, warming waters and a reduction of ice have led to a decline in cold-water plankton. This has in turn reduced the availability of prey for seabirds that feed on coldwater fish like pollock and capelin.
In addition, the fish that are available are less calorie-rich because they are eating smaller plankton. This means that seabirds are getting less energy from the food they eat, which can lead to starvation.
What is the Future of Seabirds in the Bering Sea?
The future of seabirds in the Bering Sea is uncertain. Climate change is continuing to warm the waters and reduce the amount of ice in the Bering Sea, which is likely to have a negative impact on seabird populations.
However, seabirds are resilient creatures, and they have adapted to changing conditions in the past. It is possible that seabirds will be able to adapt to the changing conditions in the Bering Sea, but it is also possible that their populations will decline.
Only time will tell what the future holds for seabirds in the Bering Sea.
