Denticle corrosion caused by ocean acidification conditions in a demersal shark species

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

Jacqueline Dziergwa, Sarika Singh, Christopher R. Bridges, Sven E. Kerwath, Joachim Enax, Lutz Auerswald

ABSTRACT:

Global ocean acidification is expected to chronically lower the pH to 7.3 (>2200 µatm seawater pCO₂) 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.

Sci Rep 9, 18668 (2019) DOI: 10.1038/s41598-019-54795-7

SOURCE (OPEN ACCESS)