This past winter, Puerto Vallarta recorded a decline of over 50% in Humpback whale arrivals according to Deep Blue Conservancy. A chief researcher recorded less than 400 of the whales in the Bay of Banderas compared to a normal year where more than 1000 are observed.
Stumping researchers was also how much further from the coast the whales remained, and the amount of time the whales stayed under water. Typically the whales emerge every half hour on average, but this year researches stated that they documented dives of over an hour.
The Puerto Vallarta Humpback Whales return from their summer feeding grounds along the Pacific coast (from California to Alaska) to the Sea of Cortez beginning in November of every year with official season beginning December 8th each year.
Researchers are not ready to sound an alarm, citing that El Niño and warmer waters could be the cause of rare migration but they will be looking at next year to see if the trends continue.
Reports from San Francisco to Canada show an increased number of whales in the area during the late Winter and early Spring.