The humpback whale recently spotted in the murky waters of the River Thames has died.
After not being sighted all day, the whale was found motionless in the waters of Greenhithe in Kent at around 5pm on Tuesday, October 8, according to volunteers from British Divers Marine Life Rescue.
The Cetacean Strandings Investigation Programme hopes to carry out a necropsy of the body today to identify a cause of death, however, it’s speculated that the whale died from starvation.
“His death was not unexpected,” wildlife charity Whale and Dolphin Conservation said in a statement.
“Sadly, thousands of whales die across the globe every year, due to disease, disorientation, or human activity.”
Nicknamed “Hessy” by its fans, the humpback whale was first spotted on Sunday near Gravesend in northwest Kent, some 35 kilometers (22 miles) from the bustle of central London. Wildlife experts struggled to keep tabs on the whale’s movements, however, it was later spotted closer to east London.
Images of the whale suggest it could measure at least 5 meters (16 feet) from head to flukes. Typically, the species (Megaptera novaeangliae) can range from 12 to 16 meters (39 to 52 feet) in length, making it one of the largest animals on Earth. Despite its small size, there were no indications that Hessy was sick.
Humpbacks are widely distributed across the globe and can be found in all major oceans, loosely banded together in four global populations in the North Pacific, Atlantic, Southern Ocean, and the Indian Ocean.
Generally speaking, marine scientists don't know exactly why whales trap themselves in rivers and estuaries, although there are some theories, such as ocean currents pushing them off path, distress from sonar or ships, disease, or navigational accidents.
While urbanized estuaries are not their typical hangout, a number of large cetaceans have been spotted in the Thames over the years.
In September 2018, a beluga whale nicknamed Benny spent months in the Thames before swimming back out again. It lived near Gravesend for several months until departing the Thames Estuary in early 2019.
In 2006, a 5-meter (16-foot) northern bottled-nosed whale was found in the Thames, past central London and as far west as Battersea. Unfortunately, this individual did not have such a happy ending, dying from convulsions as she was being rescued. A necropsy of the whale showed her body was covered in gashes and she had died from a combination of problems including dehydration, muscle damage, and kidney failure. Her skeleton was eventually put on display at the Natural History Museum in London.