Scientists warn climate change may be driving more gray whale deaths after SEVEN washed ashore in Alaska over the weekend amid heatwave
- Climate change may be causing an uptick in whale deaths says the NOAA
- Alaska alone has seen 22 whales wash up on its shores this year
- Damage to the food network of the whales may be caused by losses in sea ice
- To research the problem NOAA scientists will embark on a mission next month
Climate change may be to blame for a rash of dead whales washing up on beaches in the U.S. and abroad.
According to the National Oceanic and Atmospheric Administration (NOAA), a whopping seven dead gray whales washed up on Alaskan shores over the July 4 weekend, continuing an Unusual Mortality Event declared by the agency in May.
The latest string raises the total to 22 in Alaska since the start of this year.
Gray whales have been documented washing up on shores across the U.S. and abroad leading researchers to explore the possibility of a climate change-induced die-off
Overall, the levels may eclipse a previous mortality event documented by the NOAA in 2000 when 96 gray whales were recorded. There are currently 91 American strandings in the books.
As reported by CNN, the whales, which can weigh up to 90,000 lbs and eat about 1.3 tons of food per day were found to be malnourished, leading some researchers to posit that there has been a disruption in the animals’ food source.
‘Scientists theorize there may have been a disruption in the gray whale food source due to a lack of sea ice in the Arctic last summer,’ NOAA public affairs officer Julie Speegle told CNN.
‘Gray whales fatten up during the summer by feeding on marine life, mostly amphipods off the ocean floor.
‘But when sea ice melts and retreats (as it did last summer), there is a disruption in the food web that results in fewer amphipods for gray whales to eat.’
Specifically, researchers say a disruption in phytoplankton, which typically falls to the ocean floor to feed animals like amphipods that the whales dine on could be having a dramatic effect.
Though the correlation between the whales’ food source and the mortality events are plausible, researchers say proving that the two are connected is tall order.
In the U.S. Alaska has seen 22 whales washed up on its shores this year, seven of which took place in early July. The sites are plotted in the map above
In addition to roving constantly across swaths of the ocean, the whales undergo one of the longest migrations of any known animals, traveling 5,000 miles between Mexico and the Arctic every year.
‘Full or partial necropsy examinations were conducted on a subset of the whales. Preliminary findings in several of the whales have shown evidence of emaciation,’ said the NOAA in May.
‘These findings are not consistent across all of the whales examined, so more research is needed.’
Ironically, scientists say the die-off could also be a result of the whale populations recent prosperity.
Though the gray whale was previously endangered, since 1994, when the species was taken off the list, its population has grown to 27,000 according to the NOAA. This boom could increase the risk of whales contracting diseases, say scientists.
To further document the problem, researchers for the NOAA are setting out on a trip across the Bering Sea to help survey the levels of plankton and other types of sea life critical to the gray whales’ food chain. The mission will begin early next month and last until August 23.
WHAT’S BEHIND A DIE-OFF OF GRAY WHALES?
Scientists have noted an unusual uptick in the amount of dead gray whales washing up on beaches.
While the cause is undetermined, some researchers say it could be related to climate change. Changes in sea ice may be killing off a critical part of the whales’ food chain.
Alternatively, an uptick in the whale population could be leading to more disease. NOAA Researchers are gearing up for a mission into the Bering Sea where they can study food networks.
NOAA Whale deaths in numbers:
U.S. State 2019