Why do whales wash up on beaches?

Early morning joggers in Mumbai who had probably never seen whales wash up on shore were in for a shock when they saw a majestic, 30 feet (12m) long whale wash up ashore on Juhu beach, yesterday (29th June 2016).

whale washes up in mumbai juhu
The whale’s carcass (Source)

Experts have identified it to be a Bryde’s Whale which is usually found in warm and tropical waters. The longest Bryde’s Whale measured in 1962 at Saldahna Bay, SA  was almost 51 feet long.

whales tamil nadu wash up
100 whales wash up on a beach in Tamil Nadu on 12th January 2016 (Source)

This incident marks the second case of whale beaching (Cetacean stranding) in India this year after a similar incident in Tamil Nadu earlier this month when about 100 whales had been stranded in Tuticorin district.

Cetacean stranding
Cetacean stranding is a phenomenon in which cetaceans (Carnivorous Aquatic Mammals that cannot survive on land like dolphins, whales, etc.) get washed up on land. These animals can be stranded after their death in water as their bodies wash up ashore or they could be stranded due to other factors as detailed below.

Why do whales wash up ashore?

Whale beaching is not a new problem; it has been recorded to be happening since as early as 300 B.C.  Although, the frequency of these incidents seems to have increased over the last few decades. Experts believe that man-made factors are the main reasons driving this phenomenon. It can be very tricky to know why whales wash up on shores, mainly because there are many factors involved. Some of the most common reasons are enlisted below:

  • Pollution

Experts believe that chemical pollution causes whales to be born with deformities. It also affects live whales and can kill them. These dead whales are then brought in ashore by the tides. This pollution is mainly caused by humans releasing dangerous and toxic chemicals into water bodies.

  • Confusion

Whales ascertain their location and navigate through a method known as echolocation, where they use sounds as a navigation tool. Many scientists believe that man-made sonar can interfere with a whale’s navigation system and leave them disoriented causing them to go into shallow waters, and eventually, these whales wash up on land.

  • Earth’s magnetic field

If there is a slight change in the earth’s natural magnetic field, it could also potentially interfere with a whale’s brainwaves, causing it to lose its sense of direction.

  • Global Warming

The heat from the earth’s surface can cause icebergs to melt which in turn causes a shift in the tides of water bodies which could lead to schools of fish to shallow waters. These groups of fishes serve as a food source for whales.

  • Disoriented pack leader

Whales are highly social animals that travel in large pods. In some cases, if the pack leader is sick/confused, it could lead the entire group of whales to wash up ashore.

It is tough for authorities to save a whale that is stranded on land, let alone a whole pack of them. Out of the 100 odd whales that had washed up in Tamil Nadu earlier this month, only 36 were saved.

What happens after whales wash up on land?

If the whale is found alive, then all measures are taken to return it back to the ocean. If it is dead, then the carcass has to be disposed of. Bigger the whale, harder is its disposal.  Sometimes government agencies hand over the carcass to scientists or Museums to study the whale. In the UK, the Cetacean Strandings Investigation Programme (CSIP) handles all such cases.

Sometimes the whale’s carcass is too decomposed to move, so it is either buried or moved far away from areas inhabited by people. The decomposition of a dead whale is quite a messy process, and the smell from all the gases being released from the body is unbearable.

Dead whales can also explode due to the enormous amounts of gas building inside them. This adds to the hazard of dealing with the situation (Check out the video below). They are also huge and weigh several tons, thereby requiring special machinery to be lifted.

Interesting Fact
In the UK, whales (along with sturgeons and porpoise) are designated as Royal Fish. If a whale is found on any coast then according to a law made during the reign of Edward II, the King owns the head of the Royal Fish, and the Queen owns its tail. (Source)


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