Abstract

Mass strandings of cetaceans have occurred around the world for hundreds of years. In many regions, such as Cape Cod, Massachusetts, USA, these events have occurred regularly throughout recorded history. In other regions, these events are quite rare. Although early events were viewed as opportunities to harvest blubber and meat, there has been a general shift in many cultures to protect and conserve marine mammals. Early efforts by scientists to investigate these events were based on the belief that mass stranded animals came ashore because they were ill; however, these studies revealed that in many cases, the majority of animals appeared healthy, other than the direct effects of the stranding itself. As a result, when mass strandings occur, or when groups of dolphins or whales are found out of habitat (such as in rivers), attempts are made to rescue the animals and return them to the safety of deeper, offshore water. Response to out of habitat and mass stranding events is complicated and resource intensive under the best of conditions. Efforts to herd or drive animals to deeper water require coordinated on water maneuvers with multiple vessels. Rescue and relocation of individuals or groups of animals requires a large number of people, appropriate vehicles, and support resources. Maximizing data and sample collection from dead animals is also a labor intensive priority with many requirements. When efforts such as this are undertaken in remote locations, a myriad of additional challenges emerges. On 31 May 2008, a group of melonheaded whales (Peponocephala electra) were observed far into an estuary at the port of Antsohihy, Madagascar. Initial estimates of group size exceeded 100 animals, though this number is likely an underestimation given the scale of the local mangrove and the absence of a skilled observer. An international response team from the United States was dispatched to assist in the response and to investigate possible causes of the event. While local residents attempted to rescue some animals, many did not survive the first few days of the event. Responders from the Wildlife Conservation Society, International Fund for Animal Welfare, and Woods Hole Oceanographic Institution operated from Antsohihy from 9–13 June 2008. One team focused on live animal herding and response and a second team directed efforts at necropsy and sampling of dead animals. Both teams were faced with many logistical challenges while deployed which affected the success of the operation. Limited resources, challenging communication, lack of infrastructure and cultural differences all influenced the response. Details of the event and subsequent response highlighted the need for organized response structure, ingenuity, flexibility, and the value of engaging local individuals and agencies in response efforts.

* Presenting author