Tuesday, October 16, 2018

Sea Snail Shells are Dissolving in Increasingly Acidic Oceans


Since the beginning of the Industrial Revolution, the ocean has experienced approximately a 30% increase in acidity. The impact of ocean acidification is detrimental throughout many oceanic species.  Marine organisms that produce calcareous external coverings in particular are greatly affected by ocean acidification. A new study surveyed Charonia lampas, a calcifying species of snail, and revealed the alarming effects that increased ocean acidity can have on these organisms.

These animals draw calcium directly from the seawater in which they live. The calcium is then carried to the shell, and converted into calcium carbonate. If these organisms are exposed to an increased oceanic pH (more alkaline), it provokes higher levels of calcification. However, the decreasing pH of the ocean and rising acidity leads to lower levels of calcification. These lower levels of calcification can cause many detriments to these organisms, such as shell dissolution and increased mortality rates.

Snails exposed to increased levels of acidity off the coast of Japan were specifically examined in this study. The ocean along Japan's coastline is naturally more acidic because of the presence of large volcanic vents. These vents constantly have carbon dioxide bubbling through them, therefore the pH level of the ocean surrounding this area is low. Scientists used this low pH oceanic area to survey the effects of ocean acidification on Charonia lampas. To analyze the impact of a low pH environment on shell generation, researchers used CT scans to measure the shells of affected/exposed snails. The CT scans of the compromised snails were compared to CT scans of healthy snails. This comparison showed that the shells of the compromised snails were thinner, smoother, and less dense than the shells of healthy snails. The CT scans also revealed that extreme thinning of the shells caused portions of flesh to be exposed. This finding suggests that ocean acidification not only hinders the development of shells, but furthermore can cause the dissolution of shells.

This study is among many others which have extensively analyzed the impact that ocean acidity has on organisms with calcareous shells. As global warming continues to ravage Earth's atmosphere, and the oceans continue to take up more and more carbon, ocean acidification will become substantially worse. It is likely that these calcifying species will not be able to survive if the acidic condition of the oceans worsen. The ecological impact on these organisms will be vast and irreversible.

Posted by: Hayley Fecko (2)


8 comments:

  1. I have learned about this concept in a coupe of my classes and it is truly alarming! With the increase in acidity and the decrease in calcium in the water, some crustaceans are unable to form shells making them more vulnerable to predators. As global warming continues to increase more and more of these species will lose parts or all of their shells, which in turn can lead to the extinction of a particular species. These findings are truly alarming!

    Posted by: Katarzyna Mosio

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  2. Poor snails! I have never heard of this concept before and I am definitely alarmed. Everyday, the effects of global warming seem to become more wide spread. Is this change in ocean acidity one that could potentially be reversed, or are we stuck at a point where minimization of further damage is our only option?

    Posted by Jamie Downer

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    1. Unfortunately, environmental scientists have looked into reversing ocean acidity and have not found very promising solutions. Although there are methods that can be implemented in order to reverse ocean acidification, researchers have estimated that with the most aggressive carbon dioxide removal techniques, it will take more than 700 years to revert oceanic conditions to the point of the pre-industrial era.

      Posted by: Hayley Fecko

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  3. I have read about ocean acidification due to increasing CO2 levels but I did not think about the calciferous sea animals and how it might adversely affect them. I'm assuming other calcium carbonate containing shelled animals such as mollusks and soft-shell clams must also be experiencing the same phenomenon?

    - Posted by Priya Bikkani

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    1. Your assumptions are correct! All calcifying oceanic species are experiencing this same phenomenon. For example, organisms such as algae, starfish, barnacles, sea urchins, and corals can all be affected by ocean acidification.

      Posted by: Hayley Fecko

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  4. It sounds like the levels of calcification are directly related to the pH of the ocean, but I'm not entirely sure how. What's happening to the calcium in the ocean as it becomes more acidic? Is there just less calcium or is something interfering with the calcium that's there?

    -Matt Murdoch

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  5. This was interesting. I did not realize how much ocean acidification could affect animals in the ocean physically. This is unfortunate. I would be interested in knowing how exactly this is thinning out their shells so perhaps methods to prevent this can be implemented.

    Posted by Alexandra Rios

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  6. I have, like others above, heard of ocean acidification and many of the cons associated with it; however, I never correlated the effect to these types of sea creatures. What happens to these snails when their shells disintegrate or when flesh is exposed? How will this effect of not being able to create a steel effect the ocean ecosystem as a whole and the chain of predator prey?

    -Maddie Powers

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