Climate change is widely associated with floods, cyclones, sea-level rise, and extreme weather events. However, another serious environmental crisis is developing beneath the surface of the world’s oceans. Ocean acidification, often called the ‘other carbon problem,’ is emerging as one of the most dangerous consequences of global warming. Although it receives far less public attention than other climate-related threats, it poses significant risks to marine ecosystems, fisheries, biodiversity, and coastal livelihoods. For Bangladesh, a country highly dependent on the Bay of Bengal for food, employment, and economic development, ocean acidification represents a growing challenge that demands urgent attention.
Ocean acidification occurs when the ocean absorbs excessive amounts of carbon dioxide (CO₂) from the atmosphere. Human activities such as burning fossil fuels, industrial production, transportation, and deforestation release vast quantities of carbon dioxide every year. Scientists estimate that the oceans absorb nearly one-third of these emissions. While this process helps reduce greenhouse gas concentrations in the atmosphere, it also changes the chemistry of seawater. When carbon dioxide dissolves in water, it forms carbonic acid, lowering the ocean’s pH and making it more acidic. This reduces the availability of calcium carbonate, a vital mineral that corals, shellfish, oysters, and other marine organisms need to build and maintain their shells and skeletons.
Since the Industrial Revolution, ocean acidity has increased by approximately 30 percent. Scientists warn that if greenhouse gas emissions continue at current rates, ocean acidity could reach levels not experienced for millions of years. Such changes threaten marine life and could disrupt entire ocean ecosystems.
Although Bangladesh contributes only a small share of global greenhouse gas emissions, it is among the countries most vulnerable to climate change. The country’s long coastline along the Bay of Bengal and its dependence on marine resources place it at particular risk. Fisheries, aquaculture, coastal tourism, and marine biodiversity all depend on healthy ocean ecosystems. The Bay of Bengal is home to a wide variety of marine species, including fish, crabs, shellfish, sea turtles, dolphins, and microscopic organisms that form the foundation of marine food chains. Ocean acidification threatens many of these species, particularly shell-forming organisms and plankton. These small organisms are essential food sources for larger marine species. A decline in their populations can have cascading effects throughout the ecosystem, reducing fish stocks and weakening biodiversity.
Experiences from around the world highlight the seriousness of the problem. Australia’s Great Barrier Reef has suffered extensive coral bleaching due to rising ocean temperatures and changing ocean chemistry. Oyster farms along the Pacific coast of the United States have experienced declining production because acidic water weakens shells and reduces survival rates. Small island nations in the Pacific are also witnessing damage to coral reefs and fisheries that support local economies. These examples demonstrate that ocean acidification is no longer a future concern but an ongoing global challenge.
For Bangladesh, one of the greatest concerns is the impact on fisheries. The fisheries sector contributes significantly to the national economy and supports the livelihoods of millions of people. Fish is also one of the main sources of protein for the country’s population. Ocean acidification can affect fish growth, reproduction, and survival, while shellfish species such as oysters, clams, and crabs become increasingly vulnerable as their shells weaken in acidic waters. Declining fish stocks would threaten food security, increase prices, and create economic hardship for coastal communities.
The Sundarbans, the world’s largest mangrove forest and a UNESCO World Heritage Site, may also face indirect impacts. The Sundarbans plays a critical role in protecting coastal communities from cyclones and storm surges while supporting rich biodiversity. Many fish and shrimp species breed in coastal waters connected to the mangrove ecosystem. Changes in seawater chemistry, combined with rising salinity and temperatures, could affect these breeding grounds and reduce the productivity of fisheries that support local livelihoods.
Coral ecosystems around St. Martin’s Island are equally vulnerable. Coral reefs are highly sensitive to changes in ocean temperature and acidity. Acidic conditions weaken coral structures, making them more susceptible to bleaching and disease. Damage to these reefs would reduce marine biodiversity and undermine tourism opportunities associated with the island’s unique ecosystem.
Ocean acidification is not only an environmental issue but also an economic and social challenge. Declining fish production could reduce incomes for fishing communities and affect thousands of families involved in fish processing, transportation, and marketing. Women who depend on fisheries-related activities may face particular economic difficulties. Reduced household incomes can affect children’s nutrition, health, and education. In some cases, environmental degradation may contribute to migration as people seek alternative sources of livelihood.
Addressing this challenge requires both global and national action. Reducing carbon dioxide emissions remains the most effective long-term solution. Industrialised nations, which are responsible for the majority of historical greenhouse gas emissions, must accelerate the transition to renewable energy and support climate adaptation efforts in vulnerable countries. International cooperation and climate finance are essential to protect marine ecosystems and coastal populations.
At the national level, Bangladesh should strengthen marine research, environmental monitoring, and coastal conservation initiatives. Universities, research institutions, and government agencies need to work together to better understand changes occurring in the Bay of Bengal and develop appropriate adaptation strategies. Protecting mangrove forests, conserving marine habitats, expanding marine protected areas, and promoting sustainable fishing practices can help strengthen ecosystem resilience.
Public awareness is equally important. Many people remain unaware of ocean acidification and its long-term consequences. Journalists, educators, researchers, civil society organisations, and youth groups can play an important role in raising awareness and encouraging environmentally responsible behaviour. Civic engagement can also help promote stronger environmental policies and greater accountability for pollution and climate action.
Ocean acidification is a hidden but dangerous consequence of global warming that threatens biodiversity, fisheries, coastal ecosystems, and human livelihoods in Bangladesh. Although the process develops gradually, its long-term impacts could be severe for the Bay of Bengal and the millions of people who depend upon it. Protecting the ocean is not only essential for marine life but also for food security, economic stability, and sustainable development. Bangladesh and the international community must act now to address this growing threat before its consequences become irreversible.
The writer is the Editor and CEO, News Network
