In the San Francisco Bay area, six gray whales have died in the past week, raising the total to 15 stranded whales this year, including 14 gray whales and one minke whale. Authorities from the California Academy of Sciences and the Marine Mammal Center are struggling to determine the causes of these deaths due to challenging necropsy conditions, with some cases suspected to be caused by vessel strikes. With a notable increase in gray whale sightings this year, experts emphasize the need for boaters to be vigilant to avoid further fatalities.