Reader Question – Lucas Nunes Martorelli, São Paulo, SP
Death is due to factors such as increased body temperature and compression of internal organs. In fact, around 80% of beached whales reach the beach dead and the survivors very weak. In 2015 alone, 57 whales were found on the Brazilian coast and, although the strandings are accidental, some scientists believe that extremely injured animals swim towards the beach as a last resort to keep their respiratory orifice out of the water and be able to breathe. The theory has not yet been proven, but the chances of survival are low and the time for help is short – a week at most. In addition, the rescue requires support from authorized institutions and the fire department to handle tons of animals. The survivors are returned to the sea and the carcasses of those who did not resist go to research institutes to be studied and then buried with the support of tractors and machines.
solid and hostile land
High weight and temperature mortally weaken giant mammals
CLEARANCE TO BREATHE
Whales rise to the surface to breathe in oxygen and when they are submerged they are not breathing. How do they do it? Well, for starters, they have lungs up to a thousand times bigger than ours. In addition, they are efficient and use about 90% of the oxygen inhaled, since they have more red blood cells and more myoglobin in the muscles.
HEAVY LOAD
A whale can be anywhere from 30 to 180 tons and only moves in the ocean because the water supports the weight. On earth, gravity causes tons to compress circulation in vital organs such as the liver, heart and lungs. Unable to breathe and transport oxygen to the body’s cells, the animal cannot resist
DEATH ON THE HIGH SEA
If most already arrive lifeless on the beach, how do they die? The causes can be as much natural as aging, diseases and attacks by predators, as a result of human action. Many die in collisions with ships, trapped in fishing nets and, of course, because of pollution, which contaminates whales and their food chain.
CANNOT COME HOT
Like other mammals, the whale maintains its body temperature around 37 oC. To protect itself from the icy waters, the skin has up to 40 cm of fat. When she runs aground, this layer does not let the heat dissipate, causing dehydration and even convulsions (if the temperature reaches 42oC). All this can lead the animal to death.
CONSULTANCY: Milton Marcondes, veterinarian and director of research at Instituto Baleia Jubarte
SOURCES: Websites ecodesenvolvimento.org, IG and Scientific American Brasil