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Strandings

The main aims of the IndoCet stranding network are to connect researchers in the region and facilitate the building of a regional response network through sharing of resources and mutal support.

What are strandings?

Stranding events of cetaceans (whales, dolphins and porpoises) can either be of individual animals or multiple animals simultaneously within a specific area. Animals are considered stranded when they are found dead or alive on the beach and are unable to return to the water. Live-stranded animals usually need medical attention or professional assistance to return to their natural habitat. Multiple animal strandings are usually referred to as “mass strandings” or “mass mortality events”.

What can strandings tell us?

Strandings can provide scientists and managers with important information on the biology and health of marine mammals and, in turn, the health of our marine ecosystems. They provide basic information on the biology and ecology of marine mammal species, such as an animal’s range, age, the types of prey it consumes, and the occurrence of diseases within populations. In fact, some marine mammal species are known only from stranded specimens. Strandings also provide important information on human impacts to marine mammals. Data collected from stranded animals teach us about interactions between marine mammals and fisheries, vessels, or marine debris. Samples collected from stranded marine mammals also provide information on marine pollution. For example, a dolphin that may have high levels of chemical contaminants in their body could have direct implications for human health, as they consume many of the same fish that we do. Ultimately all the information gathered from these events help ensure the conservation of marine mammals from a population to a species level for future generations to enjoy.

How can a stranding network help?

By examining these stranded marine mammals, stranding networks and their partners can better understand causes of mortality and factors that affect marine animal health. Other functions of stranding networks are to facilitate the humane care out of animal welfare concerns, assist in the recovery of protected species by returning them to the wild whenever possible, and help identify population threats and stressors of marine life, especially stressors that can be prevented or mitigated.

IndoCet Stranding Network: The beginning

A mass-stranding of melon-headed whales Peponocephala electra at Antsohihy in Madagascar during May/June 2008 revealed the need to build capacity for stranding response and investigation in the Western Indian Ocean region.

In order to respond to this event, scientists with expert knowledge needed to be brought in from overseas. However, responding to such events by ‘importing’ expertise also poses logistical constraints which may easier be overcome by local expertise familiar with the region and terrain.

More recently, there have been increased concerns about the potential impacts from anthropogenic activities in the region, such as increased shipping and offshore oil and gas exploration Due to the current lack of capacity, both in terms of stranding response as well as analytical expertise, as well as baseline knowledge for many populations, potential impacts may go unnoticed.

Therefore the Indian Ocean Network for Cetacean Research (IndoCet) was formed in November 2014 at a workshop about humpback whale satellite tagging on Reunion Island. IndoCet is committed to the research of all cetacean species across the Southwest Indian Ocean.

Recent stranding events in the region have shown that the need to build capacity and establish baseline knowledge is still present. However, the joint examination of a stranded pygmy sperm whale (Kogia breviceps) and a sperm whale (Physeter macrocephalus) in Kenya in 2018 carried out by local experts in collaboration with experts in South Africa and Italy via WhatsApp have shown the value for joint efforts to overcome situations where there may be a lack of local expertise.

At the last IndoCet meeting in Reunion in July 2019, the value of coordinating stranding response within IndoCet and the Indian Ocean region was discussed and a stranding coordinator was identified to provide assistance and support with stranding response, level-A data and sample collection, and training throughout the region.