Sharks Begin Climate Adaptation Strategy

Recently scientists in Australia discovered that two species of sharks are interbreeding. The common black-tip shark and the Australian black-tip shark have started producing hybrid sharks. Marine biologists in Queensland say they’ve found 57 sharks so far.

The common black-tip shark is found around the world in subtropical and temperate ocean waters while the smaller Australian black-tip shark is more suited to warmer, tropical waters. The combination of the two species — which is extremely unusual — could be a response to climate change.

Lead researcher Jess Morgan of the University of Queensland says, “If it [the Australian black-tip species] hybridizes with the common species it can effectively shift its range further south into cooler waters, so the effect of this hybridizing is a range expansion. It’s enabled a species restricted to the tropics to move into temperate waters.”

The team confirmed the cross-breeding through DNA analysis. The team found the 57 hybrid sharks along 1,250 miles of coastline on the east coast of Australia.

Jennifer Ovenden, one of the co-authors on the paper, which appears in the journal Conservation Genetics says, Hybridization could enable the sharks to adapt to environmental change as the smaller Australian black tip currently favors tropical waters in the north while the larger common black tip is more abundant in sub-tropical and temperate waters along the south-eastern Australian coastline.”

Morgan says, “You’re seeing evolution in action.” Mixing two species of animals like this increases its chance of survival. Animals start interbreeding when their existence is threatened. By combining genetics, these sharks become stronger, making them more able to withstand changes to their environment.