Photosynthetic responses to solar UV radiation of Gracilaria lemaneiformis cultured under different temperatures and CO2 concentrations.

The combined effect of ocean acidification and rising temperature enhanced the sensitivity of a red alga to ultraviolet (UV) radiation. This was reflected in an increased damage rate, decreased repair rate, and decreased ratio of repair to damage in thalli. The findings suggest that ocean acidification and warming will reduce photosynthesis by this red alga and could potentially decrease its yield in aquaculture. (Laboratory study)