Ocean flora retreating to the brink

A new study has found that the warming ocean climate is causing seaweed communities, on which fauna survive, to retreat to the brink of the continent and possibly extinction. 

According to research led by Assistant Professor Thomas Wernberg from The University of Western Australia's Ocean's Institute, modern seaweed communities to the south are becoming more similar to past communities in the north, with several temperate species moving poleward (south).

The results published in the latest edition of Current Biology predict that, given future warming, up to one quarter of species in southern Australian waters might retract towards extinction.

The researchers studied a database of more than 20,000 herbarium records of macroalgae collected in Australia since the 1940s, and found changes in seaweed communities in both the Indian and Pacific Oceans, consistent with rapid warming over the past decades.

"We found that continued warming might drive potentially hundreds of species towards the edge of the Australian continent beyond which there is no refuge," Assistant Professor Wernberg said.

The researchers believe while some species may be able to make some adjustments to cope with natural cooling and warming cycles, the predicted rate and strength of warming in the coming decades is likely to force many retreating species further south and beyond the limits of available habitat.

"The potential for global extinctions is concerning because one quarter of all macroalgal species in the world are found off Australia and these marine habitats support equally unique fish and invertebrate communities," Assistant Professor Wernberg said.

Science News Source: The University of Western Australia