AP Biology class blog for discussing current research in Biology

How are ocean conditions harming its animals?

A recent article written by Rachel Nuwer discusses the dangers of ocean acidification and how the ocean environment could compromise the fishes’ ability to swim and feed. The existence of one of the world’s most threatening predators is being threatened by ocean warming and acidification. Sharks might lose their place at the top of the marine food chain due to the changing ocean environment. As carbon dioxide levels rise in the ocean, it increases the acidity of the water. As this factor starts to rise, the teeth and scales of sharks may begin to damage, which compromises their ability to swim, hunt, and feed. According to research published in Scientific Reports, acid-base adjustments have proved to be the first piece of evidence of “dentical corrosion” caused by ocean acidification conditions. After investigating the impact of hypercapnia on a specific shark species and analyzing the acid-based regulation, the team concluded that the denticle corrosion could increase denticle turnover and compromise the skin and protection of the shark species.

A close up on the denticles and scales of a wild shark

The harsh conditions placed on the sharks could cause several consequences and ultimately could affect the whole ocean community. Biologist Lutz Auerswalk states that sharks could be displaced as apex predators, which could disrupt the whole food chain. In addition, great white sharks are already endangered, and these conditions could wipe them out completely, he states. Ocean research Sarika Singh and Auerswald, while studying over beers, stumbled upon a unique idea. After realizing that the high acidity of beet and many other carbonated beverages causes human teeth to erode, they wondered what effect more acidic ocean water might have on shark teeth.

Most studies on ocean acidification examine species that specifically build shells or other calcium-based structures, including corals and shellfish. Because sharks are large and challenging to work with, only a few studies have been conducted about how acidification might impact these animals. Only one paper has examined the effect of pH on sharks’ skin denticles or scales. The study used small-spotted catsharks and exposed them to different environments and filmed their swimming patterns. After analyzing a pectoral fin skin sample, they did not find a specific impact. However, the results were possible constrained by the low carbon dioxide concentration the researches used, compared with the high levels of acidity already present in many oceans.

To begin exploring this question for themselves, Auerswald and Singh conducted an experiment and focused on puff adder shy sharks, a small species that is easy to handle. They decided to investigate the acidification effects on the bigger scales. They divided the sharks into control and experimental groups and observed the results. After a few months, the electron-microscope analysis revealed that the concentrations of calcium and phosphate in the sharks’ denticles were significantly reduced. They noticed damaged scales on many of the sharks as well. Though the corroded scales might not impact their ability to hunt, for larger species such as the great white shark, scales play an essential role in hydrodynamics. Because denticles are responsible for an increase in swimming speed, damaged denticles could slow sharks down and make it more difficult for them to catch prey. Because many animals have been wiped out, we must strive to protect all the species that are deeply impacted by this condition.

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  1. liambilicalcord

    Awesome article. The effects of humans on our environment are, in my opinion, obvious and I have trouble believing those who say otherwise. An article I recently read ( It outlined the varying levels of acidity in acid rain and their respective effects on various animals. PH levels in our rain as low as 4 are critically damaging to frogs while it takes a bit more acidity, 6, to effect more resilient animals such as snails and clams. While I’m unsure of the critical level for sharks I can only imagine it is high. If the damage is being done to one of the most aggressive and resilient animals in the kingdom, only imagine what it’s doing to everything else.

  2. michaelchondria

    This article really impacted me as a huge fan of sharks in general, and it’s truly sad to see that the rising levels of carbon dioxide are negatively affecting ocean life. I came across an article ( that discusses the increasing CO2 levels and correlating increasing acidification in the ocean. Marine life other than sharks also suffer consequences, as the article notes that ocean acidification is detrimental to species that build their skeletons and shells from calcium carbonate. Acidification “reduces the availability of carbonate ions in ocean water, which provide building blocks for these organisms.” Even coral reefs get damaged from the rising temperatures, as corals have to “expel algae, leaving them more vulnerable to disease and less able to maintain and build their skeletal structure.” It’s quite saddening that the majority of marine life is damaged by ocean acidification, and hopefully, a solution will be given to fix the issue of rising temperatures and acidification.

  3. melaria

    DEVOXYRIBONUCLEICACID , your blog post is just another example of how our actions as humans affect our ecosystem. You wrote about how acid levels in the ocean affects sharks and I found it interesting that we also have an increase in acid levels in rain. Acid rain is rain with elevated acid levels due to pollution in the atmosphere. Acid rain has specifically affected animals in lakes, ponds, marshes, etc. Many fish eggs cannot hatch at pH levels lower than 5. If levels get very low many adult fish also die. Acid rain affects the ecosystem as much as acid levels in the oceans do. It is a shame that more efforts aren’t being taken to stop raising acid levels.

  4. largeintestein

    I feel it is so often that we only think about the atmosphere and the ozone when we talk about global warming. This article brings crucial attention to the fact that the ocean absorbs carbon dioxide, and is being directly affected by climate change! I found a great article,, which mentioned how the ocean’s acidity has increased 30% globally since the industrial revolution. They furthermore talked about placing pteropod shells in the water with the acidity projected for 2100, and how those shells dissolve! It is truly vital that more attention is brought to our oceans regarding climate change.

  5. jacuole

    Sharks have been around since the dinosaurs, so it’s so crazy to me how our actions are seriously threatening this ancient species. Devoxyribonucleicacid, you mentioned how the acidic waters of the ocean were stripping the sharks denticles of phosphate and calcium. While we don’t have an abundance of research on how acidic water affects shark’s bodies, carbonated water affects our own teeth in a similar fashion, and we have lots of research on that! According to an article from “The Epoch Times” (, adding carbon to water produces carbonic acid and lowers the pH of the solution to below 5.5. The enamel of our teeth is made up of calcium and phosphate, and the carbonic acid causes holes to form in our teeth in much the same way acid ocean waters affect sharks denticles. If this effect happens all over a shark’s body, then the abundance of holes caused by carbonic acid would definitely, like you said, affect the strength of its scales and its ability to move quickly through the water.

  6. jacuole

    Sharks have been around since the age of the dinosaurs, so it’s sad to see how our actions have such a detrimental effect on their species. Devoxyribonucleicacid, you mentioned how researchers saw levels of calcium and phosphate drop on sharks scales after they were continuously exposed to the acidic water conditions. While there hasn’t been a whole lot of research done on the sharks themselves, acidic/carbonated water has the same effect on our teeth. An “Epoch Times” article described how carbonated water causes a lower pH level than regular water. This acidic condition strips the enamel of our teeth of its calcium and phosphate, causing holes in our teeth ( If the same thing happens to sharks, those holes, even the microscopic ones, would affect their aerodynamics in the water, making it harder for them to hunt like you said.

  7. alleele

    It is so upsetting that human consumption is leading to increased acidity in the ocean and adverse effects. I found an article ( that talks about how microfibers from clothes are also harming sea life. Not only are we altering the ocean from a chemical level, we are disturbing sea life physically too. Hopefully we solve this issue soon!

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