Ecology
The white shark population that live off Australia's coast actually consists of 2 genetically different populations, according to new studies published in the journal Marine Ecology Progress Series.
This study once again confirmed that even the most serious genetic differences are not always visible in animal appearance. For example, it has been found that Desert Western Gopher turtles are actually two different species.
In this case, scientists have found that the white sharks that live in the Bass Strait represent 2 separate populations. Scientists believe that the conservation status of these populations should be reviewed.
“The genetic structure of white sharks on the western Bass Strait is different from that of sharks on the east coast, despite the absence of any physical barriers between these regions,” says John Pandolfi, research leader at the University of Queensland. – This shows that despite the fact that these sharks are constantly moving around Australia and can even cross oceans, they come home every time to mate and breed.”
During the research, Pandolfi and colleagues studied tissue samples from 97 sharks taken from fish off the Australian coast in 1989. Sharks were caught under special programs, or accidentally fell into fishing nets. Modern satellite data and acoustic research have helped scientists draw final conclusions.
Research has shown that sharks can travel thousands of kilometers, but sharks that live off the east coast do not travel west through the Bass Strait and vice versa. Even if they wander into foreign places, they immediately return home, so scientists began to think that they could split into two separate species that did not intersect with each other.
Today, scientists have found that sharks do mix all the time. However, to give birth, they go home, either east or west.
Research teams have also worked in other parts of the world and found different populations of white sharks on different sides of ocean basins, but for the first time they have been able to detect shark separation in such a relatively small region like the Bass Strait.
Like almost all sharks, white sharks are at risk of extinction, so this type of information is essential to be able to take appropriate measures to protect them until they are laws have been issued to protect all big fish.
These studies show that some populations of white sharks are more sensitive to threats than previously thought, for example, due to overfishing or changes in local habitats . Scientists believe that regional rather than national strategies should be developed to conserve sharks in both regions of the Bass Strait.