Acid-base adjustments and first evidence of denticle corrosion caused by ocean acidification conditions in a demersal shark species

• Published in: Scientific Reports
• Main Authors: Dziergwa, Jacqueline, Singh, Sarika, Bridges, Christopher R., Kerwath, Sven E., Enax, Joachim, Auerswald, Lutz
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2019
• Subjects: Multidisciplinary; Ocean acidification
• Online Access: http://dx.doi.org/10.1038/s41598-019-54795-7; http://www.nature.com/articles/s41598-019-54795-7.pdf; http://www.nature.com/articles/s41598-019-54795-7

Abstract Global ocean acidification is expected to chronically lower the pH to 7.3 (>2200 µatm seawater p CO 2 ) by the year 2300. Acute hypercapnia already occurs along the South African west and south coasts due to upwelling- and low-oxygen events, with increasing frequency. In the present project we investigated the impact of hypercapnia on the endemic demersal shark species Haploblepharus edwardsii . Specifically, we experimentally analysed acid-base regulation during acute and chronic hypercapnia, the effects of chronic hypercapnia on growth rates and on denticle structure- and composition. While H. edwardsii are physiologically well adapted to acute and chronic hypercapnia, we observed, for the first time, denticle corrosion as a result of chronic exposure. We conclude that denticle corrosion could increase denticle turnover and compromise hydrodynamics and skin protection.