Around 100 baleen whales stranded in Tuticorin

In an unusual event in Tamil Nadu at Tuticorin, around 100 baleen whales have been stranded in shallow waters and sand on 11^th January night. The fishermen noticed this unusually large pod of whales stranded in the beaches near Manapadu and Kallamozhi villages.

These whales appear to be completely disoriented as they are coming back to the shore even when pushed back to the water by the fishermen.
When one whale gets stuck in the shallow shore others hearing its distress call try to come its rescue and get stranded. However, in this case since they are repeatedly coming back to the shore, they may have got disoriented by the Navy sonars or some experimentations by the Navy. In the past, such kinds of catastrophic standings have been witnessed due to experimentations of the US Navy.

The whales depend on their advanced echolocation modes which are even more sophisticated than the sonars used by our navies. However, the man-made sonars and sounds of other equipment in water play havoc with them. There are specific frequencies which just can “jam” them and make them disoriented and get them to the shores.

The bodies of the whales are designed based on the buoyancy of water. When a whale gets struck in shallow water, the reduced buoyancy places enormous stress on its body. The huge weight of their bodies push down the vertebrae which is not designed to support such weight. Their lungs also gets compressed. Heavy internal bleeding occurs and it is a sureshot case of death unless they are pushed back into water immediately.

There have been various erroneous reports and speculations about this incident going around. The picture is not absolutely clear yet, but here are some facts:

(1) These are not baleen whales, they are short-finned pilot whales.

(2) This species (and its close cousin the long-finned pilot whale) is known to mass-strand frequently. Although this is only the third such incident in India, pilot whale mass-strandings are not uncommon and have happened for centuries in many parts of the world.

(3) It is impossible to determine the cause or even speculate about it at this point. Naval SONARs are indeed known to cause mass-strandings, but there are other possible natural causes as well- for instance, these animals use geomagnetic contours to navigate. A slight shift in the magnetism due to natural causes will make them follow the shifted contour, possibly leading to land. Also, it is thought that quakes detected around the same time in Indonesia may have confused the whales' sense of direction.

(4) Being a species with very complex social bonds, one stranded animal can lead to the whole pod following it even if they know they are heading to shallow water. This could be why they kept returning. When such an incident happens, it is common for most of the animals to unfortunately perish.

We have been keeping in touch with the field teams that responded to the incident. Although it is unfortunate and mysterious (as all mammal stranding incidents are) the teams of marine researchers and local fishermen have done a commendable job of attending to the mass stranding and doing whatever can be done. They have been staying up without a wink of sleep to monitor the situation. Kudos to them.

Thanks for sharing the detailed information. Any updates about this from the field teams?

The results of the necropsies done by the Animal Husbandry Dept have not been released yet and there has been no news on when it will be made available. Until this is released, we cannot speculate on the causes.
A few whales reportedly swam off after rescue attempts and were not found beached again, but we cannot rule out the possibility of these individuals subsequently beaching on neighbouring shores, since they seemed to have a tendency to return.
The majority of the ones that died have been buried on the same shores. It is said that these animals were healthy (going by external appearances) other than the lacerations caused by hitting rocks near the shore.
Going by an overview of the pattern of this incident, it is believed to have been possibly caused naturally, without human interference.

Sharing a link to an updated article - http://thewire.in/2016/01/27/the-man...aveyard-20232/