Experimental results for Ecklonia radiata growth and in situ incubation experiments and in situ measurements of pH within E. radiata beds in south eastern Tasmania ...

• Main Authors: Britton, Damon, Cornwall, Christopher Edward, Revill, Andrew T, Hurd, Catriona L, Johnson, Craig R
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2016
• Subjects: Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.863968; https://doi.pangaea.de/10.1594/PANGAEA.863968

Ocean acidification (OA) is the reduction in seawater pH due to the absorption of human-released CO2 by the world's oceans. The average surface oceanic pH is predicted to decline by 0.4 units by 2100. However, kelp metabolically modifies seawater pH via photosynthesis and respiration in some temperate coastal systems, resulting in daily pH fluctuations of up to ±0.45 units. It is unknown how these fluctuations in pH influence the growth and physiology of the kelp, or how this might change with OA. In laboratory experiments that mimicked the most extreme pH fluctuations measured within beds of the canopy-forming kelp Ecklonia radiata in Tasmania, the growth and photosynthetic rates of juvenile E. radiata were greater under fluctuating pH (8.4 in the day, 7.8 at night) than in static pH treatments (8.4, 8.1, 7.8). However, pH fluctuations had no effect on growth rates and a negative effect on photosynthesis when the mean pH of each treatment was reduced by 0.3 units. Currently, pH fluctuations have a positive ... : Supplement to: Britton, Damon; Cornwall, Christopher Edward; Revill, Andrew T; Hurd, Catriona L; Johnson, Craig R (2016): Ocean acidification reverses the positive effects of seawater pH fluctuations on growth and photosynthesis of the habitat-forming kelp, Ecklonia radiata. Scientific Reports, 6, 26036 ...