Dr Miles Lamare
Dr Miles Lamare, of Otago's Department of Marine Science, says the larval stages of marine invertebrates such as sea urchins are crucial to the ecosystem of the Antarctic.
However, they have naturally high mortality and any increases in stress, such as increased UV-R exposure, will be significant and have the potential to reduce their long-term viability.
He explains that the polar regions will experience higher UV-R in the marine ecosystem if ozone depletion continues and there is a reduction in sea-ice coverage. Research has shown that sea ice provides some filtering, but not enough to fully protect the larvae.
"UV exposure increases larvae mortality by about 30 per cent under the sea ice and up to 100 per cent in open water. Exposure to UV-R has also resulted in an up to 10- to 15-fold increase in DNA damage in Antarctic species, compared with temperate and tropical species."
He suggests this could be due to cold sea temperatures that substantially slow metabolic processes such as DNA repair - a factor that could indicate an increased UV vulnerability for Antarctic marine invertebrate larvae in general.
Now Lamare is looking at how the urchin larvae might be able to adapt.
Avoidance is difficult as they feed off the phytoplankton living close to the sea surface, but the production of antioxidants to counter UV damage may yet provide a sea urchin sunscreen.
FUNDING
University of Otago Research Grant
NSF Biological Oceanography Grant (International Program Supplement)