Ministry Probes Seal Mortalities


By Surihe Gaomas WINDHOEK The Ministry of Fisheries and Marine Resources will ascertain whether the deaths of seals along the coast is as a result of starvation or pathological viral infection. The ministry will conduct an aerial survey in December this year in order to determine the pup numbers along the coast. Fisheries Permanent Secretary, Nangula Mbako, through a press statement on Tuesday this week revealed that seal pups were not getting enough milk and that their chances of survival beyond weaning the survival mass of 11 kg were almost zero. As a result, many dead and dying seals have been seen along Namibia’s coastline. Recent monitoring by the fisheries ministry’s researchers show that seal adult males and females are depicting reduced weight and that their condition is very poor. “Sub-adult seals have also been observed dead along the coast from Cape Cross northward,” said Mbako. Scientific research has shown an increase in the Namibian seal population of more than 73 percent compared to the 1993 estimates. “This implies that population numbers of these mammals have reached a stage where their current food source has become insufficient to sustain their livelihood,” said Mbako. As result of the possible food shortage for seals, researchers have also noticed a mass migration of seals from the southern colonies to the northern grounds. Most lactating mother seals survive on finfish. Such a situation has also reduced or diminished the lack of contact between the mother and her pup. “Adult seals now have to compete with others for this scarce resource due to the higher numbers. Consequently, numerous pups are dying or surviving ones’ body weight are very reduced,” explained Mbako. Besides the dead adult seals along the coast north of Cape Cross, researchers have seen aborted seals pups along the shore. This is a result of lactating pregnant mothers not having enough food to support born or unborn pups. Now, the fisheries ministry is mobilizing resources to conduct an aerial survey for December this year to ascertain the number of pups. Studies are being conducted to determine whether the die-offs are a consequence of any pathological infection (viral or bacteriological) or not. Various research has also been done on the Namibian seal resource through routine pup ecological and population dynamic studies. These studies reveal that the 2006 winter pup growth rate has declined from a long-term average of 30g a day to 2g a day at the southern colony of Wolf and Atlas Bay. Mbako said that the poor growth rates in the south could be due to the fact that the pups are not getting enough milk from their mothers. It has also been found that 48 percent male and 51 percent female of the total pups at Wolf and Atlas Bay are below a threshold of post-weaning survival mass of 11 kg. At Cape Cross, only 12 percent male and 11 percent female are below the threshold. What this ultimately means is that the majority of pups in the south will not survive beyond the post-weaning period.