Pacific White Sharks Keep to Themselves

Great white sharks are capable of travelling large distances over relatively short periods of time, but a recent publication has found that the white sharks of the North Pacific have over time formed a genetically distinct population despite their ability to undertake transoceanic migrations. Essentially there is no interbreeding between white sharks from the North Pacific and those from other regions such as Australia and South Africa.

"Individuals persistently return to the same network of coastal hotspots following distant oceanic migrations and comprise a population genetically distinct from previously identified phylogenetic clades." state the authors of the article published in Proceedings of the Royal Society B. They used a combination of acoustic and satellite tags, as well as tissue samples for DNA analyses, to demonstrate this strong homing behaviour that has presumably generated this genetic isolation from other populations, frequenting areas such as Hawai’i, the coast of California and a mid ocean spot termed ‘white shark café’.

The authors emphasise that this isolation highlights the need for North Pacific white sharks to be recognised as a "demographically independent management unit". As such in management terms they may as well be a separate species, warranting their own protection measures independent of other white shark populations, even in the rest of the Pacific.

To read about the study in greater detail, along with some fantastic diagrams to help illustrate what the white sharks are up to, check out the original publication here.

Also be sure to check out ongoing research into the behaviour of South African white sharks over at the SOSF White Shark Project homepage.