Who Does It Impact?

Ocean acidification is disrupting the delicate balance among microscopic life found in every drop of seawater, triggering detrimental consequences through marine ecosystems. It also results in an alarming escalation of harmful algae species that produce harmful algal blooms, contaminating all marine life.

The disruption of the entire food web is imminent due to the loss of key species that rely on the formation of calcium carbonate shells. It also affects many organisms’ ability to regulate their internal chemistry, impacting processes such as metabolism, enzyme activity, photosynthesis, and protein function. The increased acidification of seawater leads to the dissolution of these shells, posing severe threats to many species such as coral reefs, shellfish, and plankton.

The pH of the ocean’s surface has already dropped from 8.2 to 8.1 and is expected to fall to 8.0 by 2050, and 7.8 by 2100. Once the pH levels of the ocean reach this point, the sea will be 150% more acidic and more than half of all marine life will suffer. Calcifiers have been found to disappear once pH levels hit 7.8.

Coral uses aragonite, a calcium carbonate, to grow its skeletons and form hard structures to protect itself from erosion. The increase of ocean acidity is lessening the abundance of this carbonate, creating a serious issue for coral as it is more susceptible to breakage. Corals provide habitats, food sources, and oxygen for many marine species, and if they are destroyed by the acidification of seawater, the food chain could collapse entirely.

Among the species facing detrimental impacts are Pteropods, tiny sea snails that serve as a critical part of the arctic food web, ultimately sustaining apex predators in the ocean. Projections suggest that this species may face extinction by 2100, with profound ramifications for marine ecosystems.

We are also witnessing the degradation of sea urchins, an important species that protects coral reefs from algae. Acidified conditions manifest in slower growth, smaller, thinner, and malformed protective shells, exacerbating their vulnerability.

Even marine animals that do not create calcium carbonate shells or skeletons are being threatened by the increasing ocean acidity.

Squid, vital prey for numerous marine mammals and pivotal to the fishing industry, face detrimental impacts on their blood acidity levels, affecting oxygen transport capacity.

Similarly, fish species like clownfish and damselfish exhibit vulnerability, as acidification hinders proper egg and larvae development and diminishes their olfactory capabilities, compromising their ability to detect predators. Recent findings indicate a surge in fish mortality rates by five to nine times in acidified conditions, attributed to riskier behavior.

However, some species are actually benefiting from an acidified ocean, with jellyfish and algae flourishing in the high-carbon dioxide conditions. The increase in abundance of these species is reducing available prey for higher predators, thus disrupting the food chain. While some highly tolerable organisms will become more abundant, the overall diversity of the marine environment will be lost.

From the primary consumers to the top predators, the repercussions of ocean acidification reverberate throughout the marine food web, underscoring the urgent need for concerted conservation efforts.

Underwater isn’t the only place that will be affected by ocean acidification; many vulnerable coastal communities will face significant social and economic risks as well. Fisheries will be among the most affected, with direct harvest of shellfish, pearls, and fishers facing significant depletion in resources. The wider community will be affected as many vulnerable countries rely on seafood as a main source of protein. There could be an extreme food security disruption if ocean acidification persists at this rate, with an increased need for imports, forced migration, and major job loss and loss of revenue.

The consequences of acidification also threaten the tourism industry, with a decline of coral reef health and marine life decreasing the tourist attraction to specific destinations. With less tourism, reduced profits, tax revenue, and employment are unavoidable. Alongside the economic effects, the loss of storm protection offered by reefs can result in increased damage to tourism and community infrastructure.