The Mystery of The Whale Carcass

On Monday, June 29, 2020 a magnificent whale was found by locals on the shores of Mandarmani, a famous tourist spot150 km away from Kolkata  in West Bengal . They were very excited but soon became disheartened as it was dead .It weighed around 5000 kg  and is said to be a female. This whale is believed to be belonging to the  Balaenopetra genus but it's species is yet to be identified.  The body  was  having certain wounds that look like  metallic  cuts most likely due to human interference. In order to get more accurate data the DNA of the whale is sent to the laboratories.

Source -United News of India

A similar incident  also occurred near Porbandar, at Visavada village last month, where a Blue Whale carcass was found on  the shore ,which weighed 5000kg .  The death was caused by  hitting of the  propeller fan of a fishing vessel.

Another incident in Ramanathapuram district of Tamil Nadu on  June 7, saw the death of a Whale Shark, a rare species weighing 800 kg.

Before we understand more about the possible reasons for such deaths it is essential to understand that whales are endangered species,there are different types of whales.The most famous member of whale family-

Blue Whale
Scientific name - Balaenoptera  musculus

It is the biggest animal on the earth weighing more than 114 000 kg and attains  length of about 24 to 30 metre. The female whales are much larger than male and give birth to single calf at a period of about 10-11 months. They have  life span of about 80-100 years and have a population not more than 25,000 and the "Red list" rates them as Endangered. They are almost found in all oceans of the world because they are comfortable in both warm as well as cold water .Their principal diet is krill but they also feed on small fish and crustaceans and require at least 3000 to 3600kg of feed. They move in groups while migrating or feeding and  sometimes come closer to shore to breed or catch prey. Communication is necessary for survival , the blue whale emits low frequency sounds having intensity as high as 188 decibels, which can travel for miles under water .( The blue whale is a unique and rare species and so it is necessary to protect them.)

Humpback Whale
Scientific name - Megaptera novaeangliae 

They are called so because of their unique habits to raise and bend backwards in preparation for diving.They weigh around 34000 kg and can reach a maximum of 55000 kg,  their length can be a maximum of 15 metre. The humpbacks breed after every 2 years and may have a lifespan ranging up to 50 years. Just like the blues they too feed on krill , crustaceans, plankton and small fish and consume about 1800 kg of prey over a period of 2 months . Summers are spent by the whale in cold polar water for feeding and winters are spent in tropical waters for breeding. Humpbacks are also known for their various songs which include grunts, groans....Etc.

Minke Whale
Scientific name - Balaenoptera acutorostrata

They are considered to be the most abundant species out of all rorqual  whales , weighing 9980 kg and having  length of 7-10 metre. They can be identified by their large mouths, black colour all over the body except the belly region which is white in colour.They generally breed after every  years having a single calf born and has  a life expectancy of 60 years.They are found in every ocean of the world , but they prefer cool regions as their habitat. They have  healthy population of 500,000 to 1 million, because of such a vast population they are popular targets for whalers. They generally  have their food habits same as that of Blue whales and they also feed on squids but the kills remains as their favourites. Another notable quality of the minke whales are that they are very fast swimmers  and are also very acrobatic, they often leap like dolphins.

Gray Whale
Scientific name - Eschrichtius robustus

Gray whales carry out one of the longest migrations of any animal, covering more than 20,000 km per year. They have weight more than 23000-36287kg and can have  length extending up to 14 metre.The Gray's can be identified by their curved heads and grey body with spits of white. Like the Humpback's they too reproduce after every 2 years and can live a maximum of 77 years. They feed on small invertebrates, crustaceans, molluscs, and worms . Unlike most of the above whales these whales are not  abundantly found around the globe , they are limited to parts not Pacific ocean and the Beijing Sea and have a population of 20,000.

Sperm Whale
Scientific name - Physeter catodon

The sperm whale is considered the largest whale having teeth, they are dark in colour and have a population close to 1 million.  The male Sperm whales are much larger than the females, they can be as long as 19 metre whereas females can reach a maximum of 12 metre.The female and the infant sperm whales move in schools (an average school contains 20 members) and generally prefer warmer waters. They give birth to a single offspring every 4-6 years and have a lifespan of 65 years. The males often go to colder waters which are great feeding grounds to search for squids, cuttle fishes and octopus .The sperm whales are also known to have the largest brains in the animal kingdom .


      The whales have many commercial use for the human beings , their oils are used for lighting lamps, cooking , for making soaps, candles, cosmetics; their bones are used for making umbrellas, corsets, fertilizers; their meat is consumed by humans and other animals, the greed to obtain these products has lead to the indiscriminate killing of whales by whalers which have been making these gentle giants lesser and lesser in the oceans and seas, If adequate steps are not taken to restrict these whaling activities then surely the whales will suffer extinction. Besides these activities whales are also used for entertainment  in aquariums by getting appropriate training , this surely indicates that whales are quite  intelligent animals.

              The questions which  quite predominantly asked are ,what caused the whales death? Was it just shortage of water? Was it some injury in the body? Why did the whale come towards the shore in the case of June 29 ? Did it come for breeding? Did it get diverted while migrating due to the cyclones? Did these whales change their habitat during the lockdown? Did it just come for feeding? Was it chased in the shallow water ? Or was it affected by some disease ?

The matter is of great interest to the biologist, conservation ecologist and nature lovers . Any crisis for their survival should be addressed immediately for sustainability of this magnificent creature in this environment.

By Rupak Ghosh