Niël Terblanché
THE mass abortion of seal pups along the Namibian coast has drastically reduced and the mass die-off adult seals are slowing down.
Scientists and environmentalists were baffled by the huge number of dead seals and aborted pups they discovered on the Pelican Point peninsula off Walvis Bay about two weeks ago.
At the first count, Naude Dreyer of Ocean Conservation Namibia, counted about 5 000 aborted seal pups on the beach and reported that the adult seals in the colony where he saw the die-off for the first time looked emaciated.
Since then, he counted roughly 2 000 more aborted pups.
He also reported that adult seals, especially the females that aborted the pups, were dying off as well.
In the end, the conservationist, assisted by marine biologists volunteering at the Namibia Dolphin Project, counted about 7 000 of the marine mammals that washed up on the beaches in the vicinity of Walvis Bay.
The scientists took tissue and blood samples from the dead animals.
BODY COUNT: Marine conservationist, Naude Dreyer and pilot, Mike Böttger, undertook an aerial survey of the extent of the mass die-off of Cape fur seals along the Namibian coast line to the north and south of Walvis Bay earlier this week. – Photos: Courtesy of Ocean Conservation Namibia 
BODY COUNT: Marine conservationist, Naude Dreyer and pilot, Mike Böttger, undertook an aerial survey of the extent of the mass die-off of Cape fur seals along the Namibian coast line to the north and south of Walvis Bay earlier this week. – Photos: Courtesy of Ocean Conservation Namibia 
BODY COUNT: Marine conservationist, Naude Dreyer and pilot, Mike Böttger, undertook an aerial survey of the extent of the mass die-off of Cape fur seals along the Namibian coast line to the north and south of Walvis Bay earlier this week. – Photos: Courtesy of Ocean Conservation Namibia 
BODY COUNT: Marine conservationist, Naude Dreyer and pilot, Mike Böttger, undertook an aerial survey of the extent of the mass die-off of Cape fur seals along the Namibian coast line to the north and south of Walvis Bay earlier this week. – Photos: Courtesy of Ocean Conservation Namibia
The samples were sent off to laboratories in South Africa for analyses in an effort to discover what the cause of the mass fatality event could be.
Dreyer indicated that the results of the tests are still pending.
At the time of the discovery of the first large group of dead animals, it was suspected that several factors, such as hunger and bacterial infection could be the cause of the mass fatality event.
Earlier this week, Dreyer with the help of Mike Böttger, one of Namibia’s most accomplished light aircraft pilots, undertook a survey flight along the Namibian coast where most of the known seal colonies are situated to ascertain the extent of the mass casualty event among the marine mammals.
Dreyer said the flight took them along 200 kilometres of coastline south of Walvis Bay.
“There are more dead adults and young pups to the south of Walvis Bay than there are to the north, but the numbers are not as bad as anticipated. Most of the carcasses seem to be more than a week old, meaning the die-off is slowing down quickly,” he said.
Dreyer noted that there seems to be a drastic reduction in the amount of aborted pups on the beach as well.
He indicated that it will take a while to formally collate all the data collected during the flight, adding that there are nearly 4 000 images to process before a final conclusion can be reached about the current status of the seal colonies.
Many theories about the mass die-off event have been postulated since it started making headlines around the world over the past two weeks.
A few old hands in the Namibian fishing industry said that the advent of the COVID-9 pandemic and stringent measures implemented that prevented trawlers and long line fishing vessels from fishing could have been the single biggest contributing cause of the mass die-off.
A number of sea captains agreed that hunger might have been the main contributing factor because fishing vessels were restricted to the harbour in Walvis Bay as a result of lockdown measures.
“The seal colonies on the Pelican Point peninsula and to the south of it formed relatively recently and only because of the fishing industry in the harbour. By following our vessels, the seals were assured of a steady food source. Since the fishing vessels have not been going out regularly their food supply was disrupted, so it might be hunger that is causing most of the deaths,” one retired trawler captain said.
Another conservationist said Cape fur seal females have an amazing ability to halt the gestation of their foetuses while they are still weaning pups from the previous mating season.
The mating season of the Cape fur seals occur during late November and early December and females in the harems of dominant bulls are impregnated while still weaning the previous season’s pup.
Once the weaning seal pup reaches a certain stage of growth and weight, the gestation of the new foetus continues but if that does not happen, the mother will abort the foetus growing in her womb to keep on caring for the pup that was already born.
Seal females have been known to abort their pups if they experience adverse conditions such as a sudden shortage of food or if sickness breaks out in the colony they belong to.
