• Eastern Pacific gray whales have started their northbound migration
  • Over 200 whales died during the migration season last year
  • Scientists are worried another die-off event might happen this year

As gray whales begin their northbound migration for the spring season, marine scientists are closely monitoring them to see if a mass animal die-off will occur again. Scientists are hoping that the mortality events of last year will not happen this year.

After spending time in the warm waters of Baja, California, gray whales have now started their long journey to the feeding grounds near Alaska. The migration, which traverses the West Coast, extends from February to June.

With a round trip distance of about 10,000 miles, the annual spring migration of the eastern Pacific gray whales is considered one of the longest journeys of mammals on Earth. After spending the winter season in Baja, the whales have already started their long journey to reach new feeding grounds.

As the season shifts again, these whales will embark on a return trip to the warmer waters in the California peninsula. The eastern Pacific gray whales usually begin showing up in these regions starting from December to January of the following year.

As the whales begin their long voyage across the West Coast, scientists conduct observation procedures to see if die-off would occur during the migration. The scientists are worried that the events that killed off over 200 whales last year might happen again.

According to reports, hundreds of dead whales washed up on the beaches between Alaska and Mexico during last year’s migration season. These include the 34 gray whales that were stranded in the waters of Washington State, Seattle Times reported.

It is not yet clear what triggered the whale die-offs last year. Because of this, it has been considered as an Unusual Mortality Event by local authorities.

According to the scientists, most of the whales that died last year appeared skinny and malnourished, which points to a possible problem regarding the lack of food sources along the migration route.

Due to last year’s events, marine scientists are currently on the lookout for another possible Unusual Mortality Event. However, according to senior biologist John Calambokidis of Cascadia Research in Olympia, it is still too early to tell if a die-off will happen this year.

“The limited information we have gotten so far has been a little ambiguous,” he said according to The Daily Astorian. “It may be another month before we know for sure.”

Gray Whale
A gray whale's tail flips out of the water in the Laguna San Ignacio on Mexico's Baja California peninsula on Feb. 8, 2006. Reuters/Jorge Duenes