Shark skin is covered with a special kind of scales - placoid. The acidity of water increases as a result of global warming.
Significantly large amounts of carbon dioxide entering the atmosphere are absorbed by seawater. This process leads to an increase in its acidity. Carbon dioxide, reacting with water, forms an unstable and weak carbonic acid.
Now the acid indicator of sea water is 8.1 g. However, in less than 300 years it will drop to 7.3. These data are published in a new scientific article in the journal Scientific Reports. Scientists have proven that a gradual increase in acid concentration in seawater poses a great threat to shark scales.
Even small amounts of acid can corrode flakes. Because of this, sharks begin to feel bad and are much worse oriented in space. Without strong scales, they will not be able to hunt normally. This will upset the already fragile ecosystem balance.
Biologists working at the South African University of Stellenbosch, led by L. Orswald, studied the condition of cat shark scales. For 9 weeks, the fish were kept in water with some acid content. Then scientists checked the condition of the scales.
It turned out that for those fish that were in slightly acidified water, a quarter of the scales were completely destroyed. Their health conditions have deteriorated significantly.Sharks that were in the control group and swam in ordinary water had only a tenth of the affected scales.
Interestingly, sharks can effectively resist excessive acidification of the habitat. Scientists examined the blood of 36 different fish that lived in low pH water. The results of the study showed that with an increase in the intake of carbonates in the blood, the level of carbonates increases. Because of this, these fish maintain a stable acid blood count and do not die from changes in the chemical properties of water.
Scales cannot resist fluctuations in the acidity of water, and therefore are gradually destroyed. It cannot withstand even weak carbonic acid. And the more carbon dioxide in the air, the more scales will be affected and the slower they will recover.
Scales play a huge role in shark life. They are not only protected by it. Strong scales stimulate the formation of small twists in the water. Because of this, fish can swim and hunt much faster.
Despite the fact that this experiment was not long, and only 3 sharks, which were kept in artificially acidified water, were used for it, its results are alarming. Humanity has very little time to prevent further acidification of water and prevent an environmental catastrophe.
