Ocean acidification has become a growing threat to marine ecosystems across the globe. This phenomenon, mainly caused by the absorption of carbon dioxide (CO₂) from the atmosphere into our seas, has a significant impact on marine creatures and oceanic ecosystems.
In this article we are exploring how and why this phenomenon poses a serious threat to marine life.
What is ocean acidification?
Ocean acidification occurs when carbon dioxide (CO₂), primarily from human activities such as the burning of fossil fuels and deforestation, is absorbed by the sea. When CO₂ dissolves in water, it reacts to form carbonic acid, which increases the acidity of seawater.
The main cause of this phenomenon is the rising level of CO₂ emissions in the atmosphere. Over 30% of atmospheric carbon dioxide is absorbed by the oceans, where it reacts with seawater to form carbonic acid. This process lowers the pH of seawater, making it more acidic.
Consequences of ocean acidification
- Impact on marine life: marine organisms that rely on calcium carbonate to build shells or skeletons, such as mollusks, corals, plankton, and shelled organisms, are particularly affected by acidification. The reduced availability of carbonate interferes with their ability to calcify, making it harder for them to form and maintain shells and skeletal structures.
- Food chain: pcean acidification can affect the marine food chain, as many species depend on organisms that may be impacted by this harmful phenomenon.
- Coral reef ecosystems: corals and coral reefs are especially vulnerable to acidification, as increased acidity can impair their ability to grow and regenerate, threatening biodiversity and coastal habitats.
- Global effects: ocean acidification has worldwide implications, affecting food security, the health of marine ecosystems, and local economies that depend on fishing and tourism.
What is pH scale?
The pH scale is a measure used to indicate the level of acidity or alkalinity in an aqueous solution. The abbreviation “pH” stands for “potential of hydrogen.” This scale is used to assess how acidic or basic a substance is, ranging from 0 to 14.
pH values:
– A pH of 7 is considered neutral
– A pH below 7 indicates an acidic environment
– A pH above 7 indicates an alkaline environment
Monitoring pH levels is essential to track ocean acidification and assess changes in the marine environment, allowing researchers to better understand its impact and develop strategies to protect the ecosystems.
Causes of ocean acidification
As mentioned in previous sections, ocean acidification is primarily caused by the absorption of carbon dioxide (CO₂) from human activities. The main causes include:
CO₂ Emissions
- Fossil fuels: the coal, oil and natural gas used to produce energy and power industries and transportation is the main source of CO₂ emissions into the atmosphere.
- Deforestation: both deforestation and conversion of forested land into agricultural or urban areas reduce the ability of vegetation to absorb CO₂ from the atmosphere, thereby increasing emissions.
CO₂ absorption by the oceans
- Chemical reaction: Carbon dioxide in the atmosphere is absorbed by the oceans, reacting with seawater to form carbonic acid. This process is known as carbonation.
- Increase in CO₂ concentration: as CO₂ emissions rise, greater amounts of carbon dioxide are absorbed by the oceans, leading to increased acidity in seawater.
This rise in seawater acidity disrupts the pH balance, reducing the availability of carbonate ions, which are essential for marine organisms that build calcium carbonate shells or skeletons.
Organisms that depend on these materials for survival may experience a reduced ability to calcify, which affects their growth and survival.
Human Responsibility
Human activities have altered the chemical balance of the oceans, increasing seawater acidity and negatively impacting marine ecosystems, including corals, mollusks, plankton and many other forms of marine life. In addition to deforestation and the use of fossil fuels, the main human responsibilities related to this phenomenon also include:
- The release of pollutants into air and water, which can contribute to acid formation when they interact with rainwater, increasing the acidity of surface waters.
- The discharge of industrial and urban waste, including plastics, chemicals, and food scraps, can alter water chemistry and worsen marine pollution, increasing the risk of acidification.
It’s essential to understand and address these responsibilities, to mitigate ocean acidification by adopting policies and practices that reduce CO₂ emissions, protect marine ecosystems and promote the sustainable use of ocean resources.
Consequences of ocean acidification
This phenomenon affects everyone: from marine organisms to humans, no one is excluded from the negative effects of global water pollution and the resulting climate change.
Marine organisms
Marine organisms that rely on calcium carbonate to build shells or skeletons, such as mussels, scallops, mollusks, and crustaceans, are affected by the reduced availability of carbonate ions, which compromises the formation and strength of their shells or skeletal structures. In addition, even the development and behavior of fish can be impacted: their sensory abilities (such as scent detection or navigation skills) are altered. Some types of plankton, which form the foundation of the marine food chain, may also be affected by acidification, threatening the survival of animals that feed on them and disrupting ecosystem balance.
Coral reefs
Acidification hinders the ability of corals to build and maintain their calcium carbonate skeletons over time. This can lead to coral decalcification, weakening their structures and threatening the formation of coral reefs.
Marine plants and algae
Acidification can affect the ability of marine plants and algae to absorb essential nutrients such as iron and nitrate, impairing their growth and health. Increased acidity may limit photosynthesis and reduce the ability of these organisms to produce biomass, lowering their efficiency in converting sunlight into chemical energy.
Commerce, tourism and human health
Ocean acidification can impact the survival and distribution of many marine species, with consequences for fisheries and seafood resources, putting the food security of communities that rely entirely on fishing at risk.
Changes in the availability and quality of seafood may affect human nutrition, increasing the risk of nutritional deficiencies.
How can we intervene to reduce ocean acidification?
To tackle ocean acidification it’s essential to adopt strategies that minimize the root causes of the phenomenon while protecting marine ecosystems. Here are some key ways to intervene:
- Reduce the use of fossil fuels and promote renewable energy sources such as solar, wind, and hydroelectric power;
- Improve energy efficiency in industrial, commercial, and domestic sectors to lower overall energy consumption;
- Promote public transportation, electric vehicles and reduced emissions in the transport sector;
- Create and manage marine protected areas that limit harmful human activities, safeguard marine habitats, and support the repopulation of marine species
- Support the restoration of coastal ecosystems such as mangroves, seagrass meadows and sand dune systems, which can help absorb carbon and mitigate local acidification;
- Develop and implement technologies that capture carbon before it is released into the atmosphere and store it safely, preventing it from being absorbed by the oceans;
- Continuously monitor the quality of water and the health of marine ecosystems to quickly detect changes and take appropriate action;
- Educate and engage public, local communities, institutions, and businesses on the importance of ocean protection and the steps they can take to be part of the solution;
- Implement policies and regulations that promote sustainability, ocean conservation, and the reduction of CO₂ emissions.
Adopting these strategies requires a global joint effort involving governments, international organizations, industries, and consumers.
At Ittica Buonocore we have long been committed to doing our part: we have embraced, from the beginning, only sustainable aquaculture practices that respect the ecosystems in which we farm, while safeguarding marine life and maintaining its natural balance.
Aquaculture provides a sustainable source of fish without solely relying on open-sea fishing. This helps reduce pressure on the ocean and supports the preservation of wild fish populations, preventing overfishing and stock collapse.
Furthermore, fish farming offers the chance to monitor and control environmental conditions. This includes water quality monitoring, waste management and the abolition of the use of chemicals, thereby limiting water pollution. The aquaculture industry is constantly evolving: we work every day to implement sustainable practices and advanced techniques aimed at reducing environmental impact and improving the health of both fish and consumers.
