Antarctic seal in ‘catastrophic moult’: Expert

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http://www.sundaytimes.lk/191208/news/antarctic-seal-in-catastrophic-moult-expert-381541.html published on SundayTimes on 08.12.2019

The southern elephant seal from Antarctic polar regions continued its mysterious way around the coast this week, visiting Colombo on Friday for several hours and resting on rocks off Kollupitiya beach before returning to the water. Experts pleaded with the public not to disturb the Experts pleaded with the public not to disturb the creature as it was undergoing a traumatic but natural moulting process, shedding fur and skin.

The southern elephant seal on the Kollupitiya beach on Saturday (c) Damith Danthanarayana

Southern elephant seals live in cold Antarctic regions and observers were mystified when this seal was initially spotted on a beach off Unawatuna on the south coast on November 20.

Since then it has made appearances around the coast, and in the days before reaching Colombo was seen at Lunawa on December 4, and prior to that in Wadduwa for two days and, before that, in Ahungalla on December 1.

Wherever the seal came to rest, locals gathered in numbers to photograph the unusual sight, sometimes disturbing the animal which lies passively on rocks.

Photographs taken by the paper’s Galle correspondent, Sugathapala Deeyagahage, indicated that the seal’s skin was damaged. The photographs were sent by The Sunday Times to noted veterinarian Dr. Claire Simeone of the Marine Mammals Centre in California, for her analysis.

Dr. Simeone, an expert in seal rescue and treatment, said the seal appeared to be moulting, a natural process whereby seals shed old skin annually to make way for a new one.

“Some seal species moult all of their fur and the top layer of skin over a short period once a year,” Dr. Simeone said. “Elephant seals come onto shore for a brief period to complete this normal step so that a new, clean coat can be revealed.”

Moulting is a normal process for many other species. The most familiar example is snakes, which shed their skin periodically. Some insects and spiders moult by shedding their rigid exoskeleton to let the organism grow. Birds shed old, worn feathers to replace them with fresh plumage. Cats and dogs shed fur in warm weather.

“While most animals, like pet dogs, shed hairs year-round, elephant seals do it all at once,” Dr. Simeone said. “The process is so abrupt that it’s called a ‘catastrophic’ moult. Because the animal is susceptible to the cold during this period it spends the entire month ‘hauled out’ on land.”

“During this time it spends most of the time dozing and lazily flipping sand onto itself in an attempt to manage body temperature. It doesn’t eat and may lose up to 25 per cent of its body weight. Please do not attempt to move it back into the ocean,” marine mammals expert Dr. Asha de Vos of Oceanswell added. 

Dr. Simeone said the catastrophic moult process is very taxing for the animal, so it was best to give this seal plenty of space to rest.

An expert on southern elephant seals, Dr. Greg Hofmeyr of the Port Elizabeth Museum in South Africa, states that when moulting, the old skin of the elephant seal starts to peel off like wallpaper.

He said the first real evidence of the moult is often seen behind the front flippers and around the eyes, and the entire moult takes about four weeks, with the two weeks in the middle being the most intensive.

Dr. Hofmeyr said when seals come ashore for the moult they will typically move a few times to select a good spot, and then lie in that spot for three to four weeks unless they are disturbed.

“Since the seal in Sri Lanka looks like it is in good condition, I don’t think that the moult will be an issue for him,” Dr. Hofmeyr said assuringly.

He suggested a group of volunteers be formed to keep people away from the seal. “Perhaps keep people 20m away, though the response of the seal will determine whether the distance is suitable. We used this system to guard an adult ellie seal and pup over 20 days in October-November this year. Since she was nervous, we had to keep people 100m away,” Dr. Hofmeyr said..

Dr. de Vos warned that as the moulting process is intensive the seal could feel vulnerable and threatened and become aggressive if anyone went too close to it.

“We continue to ask that people maintain a distance of at least 25m from the seal to give it sufficient space to go through this important lifecycle event,” she said.

Dr. de Vos requested any updates on the seal’s progress to be sent to of Oceanswell through @OceanswellOrg on Facebook and Instagram.

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