They received some protection in 1985 when the International Whaling Commission instituted a moratorium on commercial whaling. In the early part of the twentieth century, during the modern whaling era, the humpback whales were highly vulnerable due to their tendency to aggregate on the tropical breeding grounds and to come close to the shore on the northern feeding grounds. More than 60,000 humpbacks were killed between 1910- 1916 in the southern hemisphere, and there were other peaks of exploitation in the 1930's and 1950's. In the North Pacific, there were peak catches of over 3000 in the years 1962-3. In order to combat the problem of depletion, catching humpback whales was prohibited in the Antartic in 1939, although that plan was abandoned in 1949.
Some humpbacks have whitish, oval-shaped scars, which are the marks of parasitic sea lampreys.
Humpback whales have few predators other than man. They are sometimes harassed, perhaps killed, by killer whales, and sharks feed on their dead bodies. Little is known about the diseases that affect humpback whales. However, true rorquals get cirrhosis of the liver and mastitis. It is unlear as to whether humpbacks also get them.