Previous research suggested that whales traveled up to 18,840 miles between their feeding grounds in polar waters to the warmer tropical seas to give birth. According to a new study, it turns out that whales are likely making their annual migrations to maintain healthy skin.
For a long time scientists have wondered why whales travel these long distances every year except to give birth in the tropics away from their usual predators. This pertains to baleen whales, like humpbacks and blues, and toothed whales, such as sperm and killer whales.
Robert Pitman is a marine ecologist at Oregon State University Marine Mammals Institute. He led researchers who deployed 62 satellite tags on the four types of killer whales that inhabit Antarctic waters in order to find out the real reason for the migrations.
After tracking the whales over eight southern summers, the scientists found that some journeyed as many as 9400 kilometers (5828 miles) to the western South Atlantic Ocean, making the round trip in merely 42 days. But they didn’t do it to give birth: photographs taken by the researchers revealed newborn killer whales in Antarctic waters.
The killer whales, with their yellow skin, led researchers to put forth another explanation in 2012. To preserve body heat in the cold Antarctic they hypothesized the whales divert blood flow away from their skin. Because of this, there is a slow down in skin cell regeneration which leads the whales to warmer waters.
Note the yellow diatoms on the photo of orcas above.
Whales Continue to Strand Due to Plastics
The Cetacean Strandings Investigation Programme in the United Kingdom reported that
when it examined a 15-foot killer whale recently stranded on a beach near Lincolnshire, it found a large fragment of plastic material in the first stomach. The team is doing more testing to understand what might have killed it and where the plastic came from.
The stranding follows an even more alarming find in December 2019 further north in Scotland. A juvenile male sperm whale was found on a beach filled with 220 pounds worth of plastic bags, tubing, gloves, bundles of rope, netting, and cups.
The Scottish Marine Animal Strandings Scheme (SMASS) said of the young whale there was a load of marine debris in its stomach.Because whales' skin and blubber insulate them so effectively, bacteria inside a whale corpse can multiply quickly even when air temperatures are low. As the bacteria help to decompose the remains, they produce gases that then build up pressure inside the body, and the sperm whale on the Scottish beach was no exception. It was described as "briefly alarming as it sort of exploded and shameful as there was a load of marine debris in its stomach.”
SMASS also said it couldn’t be certain that plastic killed the whale or caused its stranding. “This amount of plastic in the stomach is nonetheless horrific, must have compromised digestion, and serves to demonstrate, yet again, the hazards that marine litter and lost or discarded fishing gear can cause to marine life.”