WASHINGTON – Young penguins in the Antarctic may be dying because they are having a tougher time finding food, as melting sea ice cuts back on the tiny fish they eat, US researchers suggested on Monday.
Only about 10 percent of baby penguins tagged by researchers are coming back in two to four years to breed, down from 40-50 percent in the 1970s, said the study in the Proceedings of the National Academy of Sciences.
Chinstrap penguins, known for their characteristic head markings that resemble a cap with a black line just under the neck, are the second largest group in the area after the macaroni penguins, and are at particular risk because their population is restricted to one area, the South Shetland Islands.
“It is a dramatic change,” lead researcher Wayne Trivelpiece, of the National Oceanic and Atmospheric Administration’s Antarctic Ecosystem Research Division, told AFP.
“There are still two to three million chinstrap pairs in this region but there were seven to eight million two decades ago,” he said.
“There is some concern now. We need to follow these animals and track them.”
The 30-year study included chinstrap and Adelie penguins in the West Antarctic and tracked the abundance of their main food source, krill, which are the small shrimp-like crustacean mainly eaten by whales, seals and penguins.
Trivelpiece was a co-author on a study published in 1992 that suggested penguin populations were surging and subsiding according to changes in sea ice — with the chinstrap doing better in warm years and the Adelie thriving in cold years.
Chinstrap penguins eat and make their nests away from the snow and ice and so are considered ice-avoiding animals, unlike their Adelie counterparts who feed in icy habitats and are seen as more vulnerable when there is less ice.
However, Trivelpiece and his co-authors now believe that krill are the real culprit for the disappearing penguin populations, and the damage affects both types of penguins.
Krill needs ice to survive, and as climate change causes more polar sea ice to melt, the tiny sea creatures cannot breed or feast on phytoplankton in the ice and their numbers fall, taking away an important source of nourishment for penguins.
“Under a scenario of global warming and increasing temperature we had prophesized that Adelies and ice-loving animals like Adelies should decline while chinstraps and ice-avoiding animals should increase,” Trivelpiece said.
But shortly after the team’s paper was published in the early 90s, the data began to change.
“From that point shortly thereafter onward, we lost those large fluxes and both species started behaving the same way and both started declining dramatically,” he said.
“By the time we had enough data to realize what was going on with the youngsters, we realized that the big difference was between the early years when there was a lot of krill around, and the later years when there wasn’t.”
Over the past three decades, krill biomass has declined 38 to 81 percent, said the study.
“If warming continues, winter sea-ice may disappear from much of this region and exacerbate krill and penguin declines,” it said.
The main driver of the decline in krill is climate change, but resurgent numbers of whales — on the rise after cuts in hunting — could be increasing the number of predators that eat krill as well, Trivelpiece said.
A large commercial fishery that is using the krill for aquaculture feeds could also be cutting back on the natural numbers, the study noted.
While the penguins are far from the verge of extinction, the researchers have urged the International Union for the Conservation of Nature to assess their status and possibly bump them higher on Red List of vulnerable species.
A rare species of ‘glass frogs’ reappear in Bolivia after 18 years
A rare species of frog native to the eastern slopes of the Bolivian Andes has been spotted in the South American country for the first time in 18 years, the investigation team that made the discovery told AFP.
The Bolivian Cochran frog is notable for its transparent belly, leading to its nickname, the "glass frog".
"The rediscovery of this species fills us with a ray of hope for the future of the glass frogs -- one of the most charismatic amphibians in the world -- but also for other species," said investigation team members Rodrigo Aguayo and Oliver Quinteros, from the Natural History Museum "Alcide d'Orbigny", and Rene Carpio of the San Simon University in Cochabamba.
Baylor student becomes second person in Texas suspected of contracting coronavirus
According to an Austin media report, state officials are investigating a potential third case. This week, a student at Texas A&M became the first person in Texas suspected of contracting coronavirus.
Health officials in Waco are investigating the second suspected case in Texas of the deadly coronavirus, which has killed at least 25 people overseas and caused the lockdown of a city in China.
The Baylor University student, who traveled to China earlier this year, is being monitored by health officials and is isolated in a room on Baylor’s campus, according to a university release.
Are you in danger of catching the coronavirus? 5 questions answered
Editor’s note: The Chinese government has quarantined Wuhan, a port city of 11 million people, and it has restricted travel to and from several other cities, including Beijing, to contain the coronavirus that has sickened more than 800 people and killed at least 25 as of Jan. 23, 2020. A case has been reported in Seattle, and officials are monitoring a patient with a possible case in College Station, Texas. This raises the question: Will this spread – to me?