Seattle- The number of gray whales off the west coast of North America has continued to decline over the past two years, US researchers say, a decline that reflects previous fluctuations in the species’ numbers in recent decades.
as rated US National Marine Fisheries Service —NOAA Fisheries in English, belongs to National Office of Oceanic and Atmospheric Administration– Posted on Friday, The latest statistics indicate that the number of whales reaches 16,650 individuals, which is a 38% decrease from its peak in 2015-2016. Whales have also had the fewest calves since scientists began counting births in 1994.
The increase in the number of whales washed up on the shores of the West Coast prompted the Fisheries Agency to announce An ‘unusual fatality event’ in 2019. Researchers are still investigating the causes of the extinction, but they say climate change, its effects on sea ice and the availability and location of prey are critical factors. Many whales washed ashore appear to be malnourished, but not all.
The population recovered from commercial hunting before a similar 40% decline occurred in the late 1980s and early 1990s. Gray whales were removed from the endangered species list in 1994.
The number of individuals increased before the whale washed up on beaches resulting in an “extraordinary mortality event” reported in 1999 and 2000, when the whale population declined by a quarter.
Scientists say that although current population fluctuations fit historical patterns, they are still worrisome.
“We need to monitor the population closely to help understand what might be driving this trend,” said David Wheeler, director of the Division of Sea Mammals and Turtles at the Southwest Fisheries Center in San Diego.
Researchers count whales as they return from their summer feeding grounds in the Arctic to the lagoons of Mexico’s Baja California Peninsula, where they nurse their young in the winter. Normally, the census is conducted over two years, but in order to better monitor the population, NOAA Fisheries is adding a third year to the current study, in which the whales will be counted as they pass through California’s central coast from late December to mid-February 2023.
Calves count when whales head north toward the North Pole. In the count that ended in May, there were 217 calves, down from 383 the year before.