Whale stranding is a phenomenon in which whales are stuck on land, usually on a beach. Other aquatic animals like dolphins and porpoises are also known to beach.
Although mass strandings have been occurring since the times of Aristotle — back then, they were considered a gift from the gods as the stranded whales and dolphins were a rich source of food and oil — experts don’t know exactly why they take place (Photo: Wikimedia Commons)
Earlier in February, 14 pilot whales were stranded near the shore of Kalpitiya, a town located on Sri Lanka’s west coast. With the help of a navy team and local fishermen, 11 of them were rescued but three died, AFP reported.
Speaking to the news agency, wildlife officer Eranda Gamage said, “They (the stranded pilot whales) had to be taken into the deeper seas so that they would not come back to the shore. The navy took them in their boats and dropped them.”
Whale strandings aren’t uncommon in Sri Lanka. In 2020, the country witnessed one of the biggest whale strandings in recent history when more than 100 pilot whales beached on the western coast of Panadura. Three of them died during the rescue operations. In 2017, around 20 pilot whales were stranded on the eastern coast before being saved by the navy and local fishermen.
Apart from Sri Lanka, Australia’s Tasmania has also seen mass beaching of whales. Last year in September, more than 230 pilot whales were stranded on the west coast of the region. Around 170 of them died even before the rescuers arrived at the spot.
What is whale stranding and why does it happen?
Whale stranding is a phenomenon in which whales are stuck on land, usually on a beach. Other aquatic animals like dolphins and porpoises are also known to beach. Most of the stranding events involve single animals but sometimes, mass strandings, consisting of hundreds of marine animals at a time, can happen.
Although mass strandings have been occurring since the times of Aristotle — back then, they were considered a gift from the gods as the stranded whales and dolphins were a rich source of food and oil — experts don’t know exactly why they take place.
Speaking to The Indian Express, Vanessa Pirotta, a wildlife scientist specialising in marine mammals at Macquarie University (Australia), said, “Whale strandings are a mystery. We don’t know why they happen.” The reasons for mass strandings are several, including the topography of the region, illness, human activities and increasing noise pollution in the oceans.
Among the major hotspots for the beaching of aquatic animals are Tasmania, New Zealand‘s Golden Bay and Massachusetts’s Cape Cod in the United States. Pirotta explained that these areas witness several instances of stranding possibly because the deep water here quickly becomes shallow due to tidal variations.
How might human activities be causing whale strandings?
Experts believe that mass strandings could be becoming more common as the health of oceans continues to deteriorate due to human interference. One of the prime reasons for such incidents could be an increase in noise pollution in the oceans.
According to a report published by Mongabay, the latest whale beaching event in Sri Lanka might have been caused due to the “recent seismic activity in the Indian Ocean”.
Several studies have shown that noise from large commercial ships, military sonars or offshore drilling severely impacts whales’ and other marine animals’ ability to use sound to navigate, find food and protect themselves. This can drive them ashore by deafening, disorienting, or frightening them.
Pirotta said, “For some, this (noise pollution) can reduce the available space to talk to each other. It becomes too loud. For others, it might be a sudden sound that spooks individuals, causing them to rise from the depths at speed.”
Another factor could be the rising temperatures of the oceans that cause changes in prey and predator distribution, resulting in whales coming closer to shore.
“Whales and dolphins often travel where there is food. Changes in prey movements due to environmental changes like sea temperature and currents may play a role in where whale and dolphin food is located,” Pirotta explained.
Can we prevent mass strandings?
It’s very difficult to prevent them. Also, as strandings happen due to several reasons, no one-size-fits-all solution would work. However, “taking more care of our actions in the ocean to try and minimise human activities which might impact marine life” might help reduce the chances of such incidents, Pirotta said.