How will the climate crisis affect one of the fiercest ocean predators? New studies published on Wednesday have investigated what can happen to highly specialized, body -cut teeth.
As carbon emissions increase, the ocean absorbs more carbon dioxide from the atmosphere, reducing pH and making sea water more acidic – a process that can affect many ocean species and ecosystems.
“Because ocean acidification is known to damage calcified structures such as corals and shells, we wanted to investigate whether the shark teeth, especially species … who swim in the mouths to ventilate their cruelty and have constant seawater, can also be vulnerable,” said Maximilian Baum, biologist, biologist Heinrich Heinrich University. married an author who was published at Heinrich University, published at Heinrich University. Science.
“Our main show is that it is not only the risk for small organisms such as corals or molluscs: even the apex predators’ teeth show visible damage under acidified conditions, which indicates that ocean acidification can affect sharks more than previously thought.” Baum said by email.
Baum and his colleagues collected 600 naturally teeth of 10 black reef sharks (Carcharhinus melanopter), located in the Sea Life Oberhausen aquarium in Germany. Many shark species lose and grow teeth, but the speed of replacement ranges from a few days to several weeks, depending on the species.
Investigators selected 16 intact teeth and 36 teeth with limited lesions and placed them in two separate 20 -liter water reservoirs with different pH levels for eight weeks.
The pH level in the water salty tank was 8.2, close to the current ocean average, and the other reservoir was more acidic water with a pH level of 7.3 and the expected seawater pH 2,300 years for 2003. An investigation published in Nature magazine.
Shark teeth, incubated with pH 7.3, showed more corrosion. – Steffen Köhler
According to the National Ocean and atmospheric Administration, since the industrial revolution began more than two centuries ago, the pH of the surface of the ocean (the ocean of the upper water layer in the ocean) has decreased by 0.1 pH units, which is approximately 30% acidity.
Compared to teeth incubated 8.2 pH, teeth exposed to acidic water had a “visible surface damage, such as cracks and holes, increased root corrosion and structural degradation,” said Sebastian Frune, a professor at Heinrich Hein University and his zoo.
This damage, investigators, can replace how sharks find and digest food.
“Many shark species use several teeth lines simultaneously, and individual teeth can be used for several weeks or even a month, so cumulative damage can reduce feeding efficiency and increase energy demand, especially species with slower replacement cycles and many dental rows that are used at the same time,” Baum explained.
Black reef shark Sea Life Oberhausen, German Aquarium. – Max Baum
As the investigation was concentrated on the teeth of aquarium shark, he had restrictions, said Ivan Nagelkerkin, a professor of marine ecology at Adelaide University of Adelaide.
First, it is unclear whether the experiment meant the same conditions as in the mouth of the living shark. Second, the study used an “extreme” ocean acidic scenario, which believed that the greenhouse gas would be emitted at current speeds of up to 2300.
Nagelkerken did not participate in recent studies, but was 2022. The part of the study, based on different types of sharks, cut in tanks containing different pH levels, and this found that shark teeth are relatively resistant to ocean acidification.
“In the new study, the extreme corrosive effect on the shark teeth that has already been depressed – this may not necessarily reflect what Sharks will experience in the future ocean or indicate whether it will affect their food,” Nagelkerken said in an email to CNN.
Maximilian Baum, the main author of the study, considers the shark jaw. – Roman Müller-Böhmas
The fear and its co -authors agreed that their investigation had restrictions, noting that “our findings show purely chemical effects of ocean acidification on dead, mineralized tissue.” However, he said his team addressed the question from another perspective and that their results were coordinated with another job that showed the visible impact.
“Our study was designed to naturally remove our teeth because there is currently very little data at the moment. In the insulated acidified sea water on the mineralized structure itself, we want to provide the basis for understanding the vulnerability of shark teeth,” said the fear.
“This approach is complementary to previous live animals and helps to emphasize the potential damage to damaged hard tissues such as teeth,” he added.
Shark teeth are the most important of their ecological success and, as the top predators, sharks are important for the overall health of marine ecosystems, Baum said.
“If the shark and their resistance weakened ocean acidification along with other stressors such as excess and plastic pollution, it can cause cascading and dominoes in many marine ecosystems.”
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