Longevity for most baleen whales is unknown. Longevity estimates include 30 to 90 years
for blue whales, 90 to 100 years for fin whales, and up to 60 years for sei whales.
1. The absence of teeth (which can be used to approximate age in toothed whales and many other mammals) makes age estimation difficult.
2. Research on baleen whale aging is ongoing. Researchers are analyzing growth patterns
on the baleen plates and on the waxy ear plug of baleen whales to estimate age.
1. The major predators of baleen whales are killer whales. Working together, a group of killer whales may attack a baleen whale much larger than themselves.
a. There are estimates that Antarctic Minke whales make up 85% of the killer whales' diet in that region.
b. Evidence of unsuccessful attempts by killer whales include teeth scars remaining on the baleen whale's flippers and flukes.
2. Large sharks may prey upon some baleen whales, particularly those that are ill, injured, or very young.
3. The small (38 cm, or 15-in.) cookiecutter sharks use suction to attach themselves to
whales, then they carve out a core of flesh with their large triangular teeth.
1. Commercial and large-scale whaling.
a. The commercial whaling industry began to expand in the 12th century.
b. The family of right whales (including right and bowhead whales) were so named because whalers considered them the "right" whales to harvest. They have immense amounts of blubber and baleen; they are slow swimmers; they are coastal species; and their bodies float when dead.
c. Whale oil was used for lighting, heating, and lubrication; as a base for the manufacture of soaps and paints; and in processing textiles and rope.
d. Baleen was used to make corset stays, umbrella ribs, fishing rods, buggy whips, carriage springs, skirt hoops, brushes, and nets.
e. As the right whales became rare, the whaling industry sought out more numerous species to harvest. In the 19th century, with improved hunting weapons and boats, faster species such as humpback, blue, and fin whales were killed in large numbers.
f. Markets for whale products expanded to the 20th century, and more modern harpoons, explosives, and factory-type processing ships were used to hunt and harvest whales. Minke whales became a major target in the 1930's, when they were hunted by whalers because larger species were depleted.
2. Indigenous and small-scale whaling.
Indigenous peoples from various coastal areas hunt some species of baleen whales for subsistence. For instance, people in coastal arctic villages hunt small numbers of bowhead whales, Minke whales, and gray whales.
3. Baleen whales may also be harmed by entanglement in fishing gear, heavy boat
traffic, pollution, and competition with humans for food resources.
4. Population estimates of baleen whale species.
This gray whale became entangled in monofilament fishing net and stranded
on a beach in Southern California.
(Photo by Stephen Leatherwood.)
1. As in any animal population, a variety of diseases can be responsible for baleen whale deaths.
2. Many types of external and internal parasites are common to baleen whales.
a. Parasites that typically infect the intestines, stomach, liver, and urogenital tract of baleen whales include cestodes, trematodes, and nematodes.
b. Baleen plates can be infested by copepods, nematodes, and protozoans.
c. A parasitic copepod attaches in the blubber layer.
d. Diatoms grow on the skin of some species, including the blue whale. This creates an olive-colored film on the skin surface.
e. Some species such as gray and humpback whales are heavily infested by external
parasites. Barnacles and whale "lice" (actually amphipods) attach to the skin
around the head, blowhole, genital area, and throat grooves. Barnacles feed on plankton in
the water. Whale lice feed on whale skin and damaged tissue such as a wound.
Baleen whales in polar areas may become entrapped in ice.
SeaWorld/Busch Gardens Animal Information Database
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