Do whales get sunburnt?
This isn’t a question I have been pondering over, however I came across an interesting article that suggests yes – they do. And as I am interested in prevention of human skin cancer and sun damage, I decided to investigate further.
In a study of different whale species scientists have found that whales get sunburnt according to their level of exposure – just like humans. Sperm whales had more exposure to the sun due to their sea surface behaviour i.e. they spend around five times longer on the surface doing activities such as foraging and socializing, than do blue and fin whales.
Sperm whales were found to have higher levels of transcription patterns of HSP70 and KIN, than whales with less sun exposure. HSP70 and KIN protect the cells that have been exposed to UV. The HSP70 resulted in less damaged to the DNA.
When there is long and persistent UV exposure, stress pathways are activated. The researchers believe that similar to humans, sensitivity to sunburn decreases with increasing frequency and duration of solar exposure. Interestingly blue whales and hammerhead sharks can increase their melatonin levels in response to increased UV exposure (a sun tanning ability). Fin whales, which have darker skin, have less sunburn lesions compared to blue and sperm whales.
The ability to change levels of pigmentation indicates that they have phenotype plasticity. What this mean is like humans, the body and its observable traits (to some extent) can change according to the environment
Laura M. Martinez-Levasseur (et al) Whales Use Distinct Strategies to Counteract Solar Ultraviolet Radiation. http://www.nature.com/srep/2013/130830/srep02386/full/srep02386.html