Effects of ocean acidification with pCO2 diurnal fluctuations on survival and larval shell formation of Ezo abalone, Haliotis discus hannai. (March 2018)

• Record Type: Journal Article
• Authors: Onitsuka, Toshihiro; Takami, Hideki; Muraoka, Daisuke; Matsumoto, Yukio; Nakatsubo, Ayumi; Kimura, Ryo; Ono, Tsuneo; Nojiri, Yukihiro
• Is Part Of: Marine environmental research. Volume 134(2018)
• Page Start: 28
• Page End: 36
• Publication Date: 2018-03
• Subjects: Climate change -- Gastropods -- Diel fluctuation -- Periodic pCO2 amplitude -- pH -- Larval shell -- Survival; Marine pollution -- Environmental aspects -- Periodicals; Marine ecology -- Periodicals; Mer -- Pollution -- Aspect de l'environnement -- Périodiques; Écologie marine -- Périodiques; Electronic journals; 577.705
• DOI: 10.1016/j.marenvres.2017.12.015
• Languages: English
• ISSNs: 0141-1136

Abstract

Abstract: This study assessed the effects of constant and diurnally fluctuating p CO2 on development and shell formation of larval abalone Haliotis discus hannai . The larvae was exposed to different p CO2 conditions; constant [450, 800, or 1200 μatm in the first experiment (Exp. I), 450 or 780 μatm in the second experiment (Exp. II)] or diurnally fluctuating p CO2 (800 ± 400 or 1200 ± 400 μatm in Exp. I, 450 ± 80, 780 ± 200 or 780 ± 400 μatm in Exp. II). Mortality, malformation rates or shell length of larval abalone were not significantly different among the 450, 800, and 800 ± 400 μatm p CO2 treatments. Meanwhile, significantly higher malformation rates and smaller shells were detected in the 1200 and 1200 ± 400 μatm p CO2 treatments than in the 450 μatm p CO2 treatment. The negative impacts were greater in the 1200 ± 400 μatm than in the 1200 μatm. Shell length and malformation rate of larval abalone were related with aragonite saturation state (Ω-aragonite) in experimental seawater, and greatly changed around 1.1 of Ω-aragonite which corresponded to 1000–1300 μatm p CO2 . These results indicate that there is a p CO2 threshold associated with Ω-aragonite in the seawater, and that p CO2 fluctuations produce additional negative impacts on abalone when above the threshold. Clear relationships were detected between abalone fitness and the integrated p CO2 value over the threshold, indicating that the effects of OA on development and shell formation of larval abalone can be determined by intensity and time of exposure to p CO2 over the threshold. Highlights: Effects of seawater p CO2 with diurnal fluctuations on larval abalone were assessed. Our results indicate existence of p CO2 threshold associated with Ω-aragonite. p CO2 fluctuations produce additional negative impacts when above the threshold. Intensity and duration of exposure to p CO2 over the threshold influence abalone fitness.