Why do whales get stranded? What does stranded mean?

On the morning of April 19, a whale ran aground in the sea near Xiangshan County, Ningbo City, Zhejiang Province. This attracted everyone's attention. In the early morning of the 20th, after being towed to the release area by local rescue forces, this large whale dived and swam back to the sea on its own. So why do whales become stranded? What does stranded mean?

1. Why do whales get stranded?

1. Unfavorable terrain

Dutch scholar Van Hiddok believes that whale strandings may be related to coastal topographic and meteorological conditions, because they often occur on coasts with gently sloping slopes. When the whale sends ultrasonic signals here, the echo signals will be distorted, making it unable to detect the location of deep water, thus causing it to get lost. However, studies in recent years have shown that coasts with gently sloping slopes do not cause confusion in echo signals. It is true that stranded whales often occur on coasts with gently sloping slopes, because it is impossible for them to get stranded in other terrains such as straits or cliffs. Therefore, the influence of terrain is unconvincing.

2. Environmental pollution

The reason why whales get stranded is environmental pollution. When the whales' habitat is polluted, they will be forced to leave their original habitat and find a suitable place to survive. During this period, marine pollution can easily affect the whales' hearing or other functions, causing them to get stranded.

3. Human interference

Some human activities can interfere with the judgment of whales and cause them to be stranded on river beaches. For example, whales are sensitive to sonar in the water. When they encounter sonar, they will run away quickly. Sometimes they will lose their way in a hurry and become stranded on land.

4. Personal illness

Simon Ingram, professor of marine conservation at the University of Plymouth, said: "A lot of times animals that end up on beaches are exhausted, malnourished, or haven't eaten because they're sick. They may be in the final stages of illness or have died at sea and then end up washing up on the beach. If a whale is stranded alone, disease and injury play a major role. Disease causes the echolocation system to malfunction, while injury and aging cause the whale to be too weak and die naturally and wash up on the beach.

5. Herd mentality

Since some whales are social animals, like sheep, there is a leader whale in a group. If the leader whale gets lost and stranded, the other whales want to rescue it but ignore their own safety, so the phenomenon of whale group stranding occurs. Veterinary pathologist Andrew Brownlow said that although we don't know why, animals in groups will eventually follow a sick leader onto the beach or get lost together.

2. What does whale stranding mean?

Whale stranding is collective whale suicide, which means that individual or group of whales venture to the seashore, where they desperately slap the water with their tails while howling in despair, and eventually become stranded and die at low tide.

In short, the reasons for whale stranding include terrain, environment, human interference, and their own diseases. The most important thing we can do is to maintain the balance of the marine environment.