Climate change will force the oceans to be more acidic and could harm sharks’ skin. Enhanced acidity eats away the animal’s denticles, which are microscopic scales similar to teeth that cover their skin. This, in turn, may undermine their swimming.
As carbon dioxide (CO2) levels grow even more, the oceans will become more acidic, resulting in a bigger issue for sharks in the future, according to Lutz Auerswald from the South African government’s Department of Agriculture, Forestry and Fisheries.
Auerswald and his colleagues tested the impacts of various aquatic CO2 scales on 80 puffadder shysharks (Haploblepharus edwardsii), a kind of small catshark that thrives in shallow water.
The species is at the moment pretty adapted to acidic waters, which are typically risky settings for aquatic animals due to the fact that more CO2 can enter the blood, obstructing oxygen from getting to the tissues. The puffadder shyshark has a workaround for this issue: it makes its blood more alkaline, which can prevent them from getting linked to health complications.
All Shark Species Could be Affected
The team of researchers put the sharks into tanks with water of pH of 8, which is the current global scale of oceans and seas, or a more acidic pH 7.3 due to the fact that it includes more CO2. After nine weeks in the acidic environments, the sharks were able to use the same methods to keep their blood alkaline. However, this was in detriment for their denticles.
This pH level, which is near the neutral, was sufficient to disintegrate a part of the mineral that creates the scales. Even though oceans are not predicted to decline to pH 7.3 until the perhaps year 2300, living close to the western and southern coasts of South Africa makes this type of shark more prone to acidic waters than the majority.
Shark teeth are composed of the same material as their denticles, so this damage could also affect the shark’s feeding. Due to the fact that denticles are present on all sharks, other species will most likely be impacted, Auerswald said.
“The compounding effects of pollution, deoxygenation, habitat destruction, and ocean acidification will all place pressure on the 1200 or so species of sharks and rays in our ocean,” Paul Cox at the Shark Trust, a UK conservation charity says.