Study Shows Heat Wave Eliminated Millions of Seabirds
The common murre, a sizable black-and-white seabird found in northern waters, has experienced a noticeable decline in its population in Alaska over the last ten years, largely due to the effects of climate change.
TroibNews 
The common murre, a large black-and-white seabird found in northern waters, has seen a notable decline in its population in Alaska over the past decade, largely due to climate change effects.
A study released on Thursday in Science indicates that a severe marine heat wave in the northeast Pacific from 2014 to 2016 led to a catastrophic decline in murre numbers, resulting in the loss of four million birds—approximately half the species in that region.
Surprisingly, the population has exhibited minimal signs of recovery, indicating potential long-term changes in the food web that may have entrenched the ecosystem in a concerning new balance.
"There's a lot of talk about declines of species that are tied to changes in temperature, but in this case, it was not a long-term result," said Heather Renner, the lead author and a biologist at the Alaska Maritime National Wildlife Refuge.
"To our knowledge, this is the largest mortality event of any wildlife species reported during the modern era," Renner and her colleagues noted in their study.
The findings raise "alarm bells," Renner explained in an interview, as climate change driven by human activities is leading to more frequent, intense, and prolonged heat waves.
With their stylish, tuxedo-like appearance, common murres are often referred to as the "penguins of the north."
Their slender wings allow for extensive travel in search of food and make them adept at diving. However, even these resilient seabirds were overwhelmed by an unprecedented environmental crisis.
The most significant marine heat wave on record began in late 2014, affecting a vast area of the northeast Pacific Ocean from California to Alaska.
The event lasted over two years, causing widespread devastation. During this period, around 62,000 starving murres were found along the North American Pacific coast, either dead or in critical condition.
Experts believe there are two primary causes for this mass mortality: increased ocean temperatures degraded the quality and quantity of phytoplankton, affecting fish such as herring, sardines, and anchovies—the main food for murres. At the same time, the warmer waters heightened the energy needs of larger fish, like salmon and Pacific cod, that compete with murres for the same prey.
"We knew then it was a big deal, but unfortunately, we couldn't really quantify the effects," Renner stated.
In the years that followed, breeding colonies struggled to produce chicks, making it difficult to gauge the full extent of the impact.
Initially, estimates suggested that about a million birds had died, but a more thorough analysis—utilizing data from 13 murre colonies—revealed that the actual death toll was quadruple that figure.
"It is just so much worse than we thought it was," Renner remarked on the new findings.
Navid Kalantari for TROIB News
A study released on Thursday in Science indicates that a severe marine heat wave in the northeast Pacific from 2014 to 2016 led to a catastrophic decline in murre numbers, resulting in the loss of four million birds—approximately half the species in that region.
Surprisingly, the population has exhibited minimal signs of recovery, indicating potential long-term changes in the food web that may have entrenched the ecosystem in a concerning new balance.
"There's a lot of talk about declines of species that are tied to changes in temperature, but in this case, it was not a long-term result," said Heather Renner, the lead author and a biologist at the Alaska Maritime National Wildlife Refuge.
"To our knowledge, this is the largest mortality event of any wildlife species reported during the modern era," Renner and her colleagues noted in their study.
The findings raise "alarm bells," Renner explained in an interview, as climate change driven by human activities is leading to more frequent, intense, and prolonged heat waves.
With their stylish, tuxedo-like appearance, common murres are often referred to as the "penguins of the north."
Their slender wings allow for extensive travel in search of food and make them adept at diving. However, even these resilient seabirds were overwhelmed by an unprecedented environmental crisis.
The most significant marine heat wave on record began in late 2014, affecting a vast area of the northeast Pacific Ocean from California to Alaska.
The event lasted over two years, causing widespread devastation. During this period, around 62,000 starving murres were found along the North American Pacific coast, either dead or in critical condition.
Experts believe there are two primary causes for this mass mortality: increased ocean temperatures degraded the quality and quantity of phytoplankton, affecting fish such as herring, sardines, and anchovies—the main food for murres. At the same time, the warmer waters heightened the energy needs of larger fish, like salmon and Pacific cod, that compete with murres for the same prey.
"We knew then it was a big deal, but unfortunately, we couldn't really quantify the effects," Renner stated.
In the years that followed, breeding colonies struggled to produce chicks, making it difficult to gauge the full extent of the impact.
Initially, estimates suggested that about a million birds had died, but a more thorough analysis—utilizing data from 13 murre colonies—revealed that the actual death toll was quadruple that figure.
"It is just so much worse than we thought it was," Renner remarked on the new findings.
Navid Kalantari for TROIB News
