Every male sings the same song, and the song changes slightly from year to year.
These rough patches of skin correspond to where humans have hair on their face. The location of these callosities is different for each whale and allows scientists to identify individuals. From 1888 to 1962, the state of Massachusetts offered a bounty on harbor seals in order to reduce the population numbers. It was thought that with fewer seals, there would be an increase in the number of fish caught by the fishermen. This is because the shark filters tiny zooplankton from the ocean with its huge gill rakers.