Blubber - Function

Function

Blubber is the primary storage location of fat on some mammals. It is particularly important for species that feed and breed in different parts of the ocean. During these periods, the animals metabolize fat. Blubber may save energy for marine mammals such as dolphins, in that it adds buoyancy to a dolphin while swimming.

Blubber differs from other forms of adipose tissue in its extra thickness, which allows it to serve as an efficient thermal insulator, making blubber essential for thermoregulation. Blubber is more vascularized—rich in blood vessels—than other adipose tissue.

Blubber has advantages over fur (as in sea otters) in the respect that although fur can retain heat by holding pockets of air, the air pockets will be expelled under pressure (while diving). Blubber, however, does not compress under pressure. It is effective enough that some whales can dwell in temperatures as low as 40 °F (4 °C). While diving in cold water, blood vessels covering the blubber constrict and decrease blood flow, thus increasing blubber's efficiency as an insulator.

Blubber aids buoyancy, and streamlines the body because the organized, complex collagenous network supports the noncircular cross sections characteristic of cetaceans.

Research into the thermal conductivity of the common bottlenose dolphin's blubber reveals its thickness and lipid content vary greatly amongst individuals and across life history categories. However, blubber from emaciated dolphins is a poorer insulator than that from nonpregnant adults, which in turn have a higher heat conductivity than blubber from pregnant females and adolescents.