EXPERT OPINION

2 3 Suddenly the dolphin perked up and slapped the sand with her tail. Soon thereafter, a big wave broke over us and lifted her off the beach. We took this as a sign and carried the dolphin deeper into the sea, over the rocks yet again and over the sandbank (photo 4). This time she swam through the backline and headed for open water. We watched her until she disappeared from view. An hour later she still hadn’t returned to the beach. People who had been watching our rescue efforts from higher ground later told us they’d seen a pod of dolphins appear behind the waves just before our third try – around the same time the dolphin slapped the sand with her tail. Maybe they had come to fetch her and she’d sensed it? Like with elephants, I think us humans recognise many of our better traits in dolphins. They are social, intelligent animals and the way they treat each other speaks to us. In the days following the incident, we patrolled the beach but didn’t see her again. I hope she is with her family. Wildlife expert LD VAN ESSEN says: There have been many recordings of dolphins beaching themselves in the Woody Cape area over the past 30 years. In 2017, the biggest mass stranding ever recorded in South Africa took place here when 38 common short-beaked dolphins ( Delphinus delphis) beached themselves. There is no definitive explanation for why marine mammals do this. Various factors that might play a role include injuries, disease and navigation errors. Earthquakes or underwater testing of weapons, for example, might disrupt the magnetic fields that whales and dolphins use to navigate. Sometimes the animals just venture too close to the coast and beach by accident. Or they might die of old age and wash out onto the sand. ( This doesn’t happen often; usually when a dolphin dies at sea, its carcass will decompose before reaching the coast.) A sick dolphin or a stressed dolphin – like a cow struggling to give birth – will often move into shallower water and can easily become stranded. This is usually the case when you find a single animal beached, or a cow with a calf. A mass stranding might be the result of the strong social bonds that these animals form: The entire pod could follow their sick or disoriented leader into trouble. Another theory posits that a marine mammal’s echo location might have difficulty interpreting a gentle slope in the sea floor near a coastline. Such a slope affects the whale or dolphin’s sonar and the animal forms a false image of deep water. There is also some evidence to suggest that poor weather and rough sea conditions, leading to dirty water and limited visibility, might negatively affect echo location.