UWA Oceans Institute

How sensitive are our seaweeds to increased warming and UVB radiation?

Dr Xiao cuts seaweed for her research

Dr Xiao cuts seaweed for her research

OCEANS ONLINE     ISSUE 6. FEBRUARY 2016

Researchers from UWA’s Oceans Institute have discovered that while increasing climate stressors generally affected seaweeds negatively, some adapted depending on the stressor.

A collaboration between Drs Xiao, de Bettignies, Olsen, Agusti, Duarte and Wernberg from UWA, investigated how combined warming and elevated UVB radiation affected the juvenile life stages of three important habitat-forming seaweeds found in Western Australia.

“In a warmer ocean Sargassum may have an advantage as it tolerated a broader range of temperatures. In contrast, Scytothalia performed better under increased UVB levels, presumably because it has an ability for fast acclimation to UVB radiation. This suggests that the balance between species in future seaweed communities in WA are likely to shift due to climate change.” Dr Ylva Olsen, a researcher at UWA said.

This could mean big future changes to the ecology of Australia’s ‘Great Southern Reef’, which UWA researchers recently found to contribute to over $10 billion in annual national income.

“The kelps and fucoids that were subject to this study form highly productive and structurally complex habitats and they are key components of the ‘Great Southern Reef’. These seaweeds are highly vulnerable to environmental stressors and are experiencing rapid decline along many temperate and subtropical coasts,” Dr Thomas Wernberg, UWA research group leader said.

The researchers also found that warming could alleviate the negative effect of UVB on growth.

“This result was unexpected, highlighting our limited understanding of the interactions between warming and UVB radiation.

“Research like this is critical for our understanding of the effects of global change on seaweeds. Not enough experiments integrate responses that are critical for survival, growth and reproduction and it is clear that we need to test for multiple concurrent stressors to mimic what happens in the real world,” Dr Olsen said.

This research is one of the first publications to come out of collaboration between researchers from UWA’s Oceans Institute and Zhejiang University’s Ocean College; Dr Xiao Xi undertook the experimental work during her six-month visit to Dr Thomas Wernberg’s research group at UWA.

The research was published in PLOS ONE and was funded by an Oceans Institute Visitors Grant, the National Natural Science Foundation of China, the International Science & Technology Cooperation Program of China, the Australian Research Council and the Hermon Slade Foundation.

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