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Ocean Acidification on Marine Life

Author: Lucy Chen

Editors: Rachel Chen and Eric Lin

Artist: Esther Chen

There are devastating consequences for marine ecosystems as a result of ocean acidification, caused by the excessive absorption of carbon dioxide in the ocean. As acidity levels rise, the balance of the ocean's chemistry is altered, creating life-threatening circumstances for marine organisms. Therefore, it is of utmost importance to protect the marine ecosystem by addressing the issue of ocean acidification. 

The rise in acidity levels disrupts the ocean’s food chain, leading to a decrease in primary producers such as phytoplankton. When these primary producers fail to photosynthesize, it leads to a decline in the population of fish, invertebrates, and others that depend on them for food.

Marine creatures, like humans, need ideal internal conditions to maintain their well-being. When the acidity of seawater exceeds the optimal range, these organisms need to exert additional energy to sustain a healthy internal chemical balance. While organisms can often adapt to heightened acidity, it diverts energy away from other crucial processes. Scientific observations reveal that in response to increased acidity in their internal fluids, mussels, sea urchins, and crabs resort to dissolving their protective shells, leading to heavy shell erosion. Therefore, even if these organisms can adapt to survive in more acidic environments, their overall health may suffer due to these adjustments. 

Numerous marine fish and invertebrates undergo intricate life cycles starting their lives as larvae during which they mature and spread to distant locations through ocean currents. These larvae, being extremely small, become particularly susceptible to heightened acidity levels. For instance, sea urchin and oyster larvae face developmental challenges when exposed to increased acidity. Additionally, fish larvae experience a loss in their capacity to smell and evade predators. The susceptibility of these larvae implies that even though organisms may successfully reproduce, their offspring might not survive to reach adulthood due to these adverse effects. 

Ocean acidification is weakening structures in the Caribbean and cold-water reefs between Scotland and Norway, among other places on the planet where coral formations are suffering. It also presents a serious risk to the Great Barrier Reef, which has seen a 50% decrease in surviving corals over the previous thirty years. In addition to reducing fish habitats, this reduction jeopardizes the reef systems' overall resilience. Furthermore, these modifications may pose a hazard to the native fisheries in the oceans surrounding Patagonia. 

The Antarctic region is undergoing notable and concerning changes. The incredibly frigid seas there are so rich in carbon dioxide, causing animals with shells to break down in acidic circumstances, affecting the food sources for fish, birds, and mammals, among other marine life. 

Ocean acidification is attributed to the increase in carbon dioxide levels. Over the last two centuries, the earth's oceans have absorbed over 150 billion metric tons of carbon dioxide released from human activities. The surge in atmospheric carbon dioxide levels has primarily resulted from the combustion of fossil fuels like coal, gas, and oil, coupled with changes in land uses such as converting natural forests into agricultural areas. Climate change also contributes to ocean acidification as rising temperatures increase acidification levels in the ocean. Pollution, particularly from agricultural practices, plays a role in the increase of ocean acidification as excessive nutrient runoffs cause algae growth, resulting in oxygen depletion and increasing acidification levels in the affected areas. 

It is important to address the root causes of ocean acidification, including decreasing carbon emissions and supporting sustainable agricultural practices to mitigate the impact on marine life and the broader ecosystem. We can also enhance water quality by monitoring and regulating localized sources of acidification stemming from runoff and pollutants such as fertilizers. We can practice sustainable management of habitats by bolstering coastal protection measures, decreasing sediment loading, and employing marine spatial planning strategies. Doing so will help protect the ocean's delicate balance and ensure the continued health and well-being of marine life and the communities that depend on it.



Fisheries, NOAA. “Understanding Ocean Acidification.” NOAA,

their%20shells%20and%20skeletons. Accessed 5 Jan. 2024.  

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The Ocean Portal Team    Reviewed by Jennifer Bennett (NOAA). “Ocean Acidification.”

Smithsonian Ocean, 11 May 2023,

“Effects of Ocean and Coastal Acidification on Ecosystems.” EPA United States

Environmental Protection Agency, 1 Mar. 2023,

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