Wide-ranging Species Will Have The Edge As Oceans Warm

In response to global climate change, marine species that already have large ranges are stretching their territories the fastest, according to new research from University of British Columbia biodiversity experts.

The research is among the first thorough looks at how traits other than thermal niche affect marine creatures’ ability to respond to climate change. It just might help advance global predictions of how different species redistribute as the oceans heat up, and pinpoint the species in greatest jeopardy.

Lead author Jennifer Sunday, UBC biodiversity researcher, says:

“We have a bit of a mystery as to why some animals are moving quickly into cooler waters, like the green sea urchin that is decimating kelp forests in Tasmania, while other species aren’t moving at all.

Our findings indicate that animals which already have wide-latitudinal ranges, habitat generalists, and species with high adult mobility displayed the quickest and greatest range shifts. The flip side is that small-ranging species are in increased jeopardy as our planet’s oceans continue to warm.”

For their lab, researchers used the fast-warming waters off Australia’s east coast, a global marine hotspot.

In Eastern Australia, the ocean has been warming four times faster than the global average. Many marine species have been appearing further south than ever before.

By factoring in species traits, as weel as predictions based on the warming pattern in the region, the researchers were able to more than double their capability to account for variation in range extensions.

The tiger shark, short-tail stingray, yellowtail kingfish, and the Maori wrasse were some of the fish species with the biggest range shifts in the region. Filter-feeding barnacles, omnivores that are notoriously invasive, also displayed some of the largest expansions of territory.

On the other end of the spectrum, the spotted handfish, a coastal species in the same region, hasn’t extended its distributional range into cooler waters despite shifting temperatures.

Jennifer M. Sunday, et al.
Species traits and climate velocity explain geographic range shifts in an ocean-warming hotspot
Ecology Letters DOI: 10.1111/ele.12474

Photo: Graham Edgar, University of Tasmania.