Acidified oceans may corrode shark scales

shark
Credit: CC0 Public Domain

Prolonged exposure to high carbon dioxide (acidified) seawater may corrode tooth-like scales (denticles) covering the skin of puffadder shysharks, a study in Scientific Reports suggests. As ocean CO2 concentrations increase due to human activity, oceans are becoming more acidic, with potential implications for marine wildlife. Although the effects of acidified water have been studied in several species, this is the first observed instance of denticle corrosion as a result of long-term exposure.

Lutz Auerswald and colleagues investigated the effects of exposure to acidified seawater in puffadder shysharks. The authors found that in three sharks housed in acidified seawater for nine weeks, 25% of denticles on average were damaged, compared to 9.2% of denticles in a of three sharks that had been housed in non-. They suggest that such corrosion may impair the sharks' skin protection and open-water sharks' ability to swim, as denticle surface affects their swimming speed. They also speculate that similar corrosion may occur in sharks' teeth (which have the same structure and composition as denticles), which may negatively impact their feeding.

However, the authors also found that although exposure was linked with increased carbon dioxide concentrations in blood taken from a total of 36 sharks housed in acidified seawater for different periods of time, concentrations of carbonate also increased. This prevented the blood from becoming more acidic, suggesting that these may be able to adjust to high CO2 conditions during periods of exposure.


Explore further

Sharks found to exhibit altered swimming behavior when exposed to more acidic water

More information: Acid-base adjustments and first evidence of denticle corrosion caused by ocean acidification conditions in a demersal shark species, Scientific Reports (2019). DOI: 10.1038/s41598-019-54795-7
Journal information: Scientific Reports

Provided by Nature
Citation: Acidified oceans may corrode shark scales (2019, December 19) retrieved 16 February 2020 from https://phys.org/news/2019-12-acidified-oceans-corrode-shark-scales.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
5 shares

Feedback to editors

User comments