86 Dolphins Founds Dead in a Beach of Hottentots Bay Namibia

Eighty-six (86) Dusky dolphins, including newborns and calves, were found dead on the beach of Hottentots Bay, some 40 km (25 miles) north of the southwestern coastal town of Luderitz by a crew of a commercial lobster vessel last Friday.

The dolphins may have been stranded for a week before it was discovered as the mammals are in decomposed state and hyena, jackals and seagulls have been feeding on the carcasses, according to Kolette Grobler, a senior marine biologist of the Ministry of Fisheries and Marine Resources at Lüderitz.

Grobler described it as "scene beyond sad" and suspected that newborns were aborted due to stress by their mothers. A carcass of a whale was also found among dead dolphins but she deems that it must have stranded for some time long before the dolphin, as the carcass is in a mummified state already.

Five years ago, Grobler reported that there was another mass stranding of about 33 animals five years ago, but all, except for one was assisted back to the ocean. She reckons that this may have been the biggest fatal stranding of dolphins over the past 30 years.

Dusky dolphins (Lagenorhynchus obscurus), known for their impressive aerial acrobats, occur in parts of southern Africa, South America, Australia, New Zealand and at several sub-antarctic islands. In southern Africa, they are found from central Angola to close to Cape Town in South Africa. Dusky dolphins are often spotted in cool, upwelling waters, and prefer cold currents. 

Grobler and her study team provided three possible theories of what may have caused the stranding. One theory is that one of the dolphins was sick or injured and ventured to the shallow waters and gave a distressed call. Dolphins, known for being compassionate and supportive animals may have attracted the others to support the distress call, which eventually leads to their loss.

The second theory is that the mammals may have become disoriented causing them to accidentally beach on Hottentots Bay. One suspected culprit is the regular seismic survey in the Atlantic Ocean along Namibia's southern coast to prospect for oil and gas on the ocean floor. Namibia's fisheries sector has often complained that these seismic surveys had led to a decrease in their fish catch. The third theory is that the dolphins may have preyed on a smaller fish, such as pilchards that may have ingested toxic plankton in the area. Grobler added that they will have to check the records when the seismic surveys were conducted, and will do further testing on to know what truly caused the massive stranding.

The study team admitted that they could not take samples of the dolphins as it is already at a decomposed state, but will however take water samples to determine if the dolphins ingested toxic plankton.

The Ministry of Fisheries and Marine Resources will investigate the cause of the mass stranding and death of the dolphins.

The dolphin's carcasses will be left where they were found as it is a good source of food for scavengers in the area.