Naude Dreyer of Ocean Conservation Namibia (OCN) recently came across a shocking discovery when he spotted over 5,000 Cape fur seal foetuses along the shores of Namibia.
The fetuses were a large portion of the expected new pups which should have arrived this year.
Dreyer flew his drone over Walvis Bay’s Pelican Point seal colony early in October and counted hundreds of pup bodies.
He revealed in a post on his Twitter account; "This is tragic, as it makes up a large portion of the new pup arrivals expected in late November."
Dr Tess Gridley of the Namibian dolphin project and Stellenbosch University in South Africa is part of the research study team who is monitoring the situation. Dr Gridley revealed that dead pups are commonly found at this time of year however not at this extreme scale.
Cape fur seals are mostly found along the coasts of Namibia and South Africa. The females are known to give birth in November and December. However, when there is a shortage of food, seals will often abandon their young or abort their fetuses to save food for the other seals.
Early in August, Dreyer started noticing several bodies which seemed normal, but became even more concerned after spotting thousands in October.
In the Cape Cross colony, which is further north, over 150 pre-term pups has also been found.
Gridley added that, even though an estimate of 5,000 foetuses have been seen, it is still difficult to be certain of the real death toll as many carcasses are eaten by scavengers.
Gridley added that; "We are concerned about emaciated juveniles and adult females as well, which have also been observed at Pelican Point and to the north – indicating a wider scale to this event. This event could disrupt the normal breeding cycle at the affected colonies. Normally, females will give birth to a pup each year, and they come into oestrus shortly afterwards and mate with the bulls. With females aborting pregnancies, they may come into oestrus earlier, but the males may not have organised themselves for mating. Also, the females are very thin and may not be healthy enough to reproduce."
Not only could this happen due to the lack of food, but also disease and toxins. However, Gridley stated that in this case, there is not enough data yet to confirm the reason why such a huge amount of babies were found.
A similar experience where a large-scale of pups were found happened in 1994. The cause was identified as a combination of malnutrition and a secondary bacterial infection, Streptococcus phocae.
A vet, Dr Brett Gardner, also spoke out and said that "In addition to females being thin and possibly having a decreased likelihood of falling pregnant in the coming breeding season, there will be a significant lack of recruitment of new young individuals into the population in the next few years once the foetuses that were now lost are supposed to be maturing into reproductive adults. Without knowing the extent of this or what is causing it means we do not know what risk it carries for repeat events of catastrophic die-offs in the future."
A team of scientists are investigating this matter, they are gathering data for analysis by using drones to count the bodies and collecting biological samples to establish possible causes.