The Fundamental Issue with Ocean Acidification
Ocean acidification occurs when excess carbon dioxide (CO2) from the atmosphere dissolves in seawater, forming carbonic acid that lowers the ocean's pH level. This makes the water more acidic, disrupting the balance of marine chemistry. The primary problem is that it impairs the ability of many marine organisms to build calcium carbonate shells and skeletons, leading to widespread ecological disruptions.
Key Biological and Chemical Impacts
The reduced pH interferes with calcification processes in species like corals, mollusks, and some plankton, causing thinner shells and slower growth. It also alters ocean chemistry, reducing the availability of carbonate ions essential for these structures. Additionally, acidification can affect sensory functions in fish and other organisms, altering behaviors such as predator avoidance and reproduction.
Practical Example: Effects on Shellfish Industries
In regions like the U.S. Pacific Northwest, ocean acidification has led to 'dead zones' where oyster larvae fail to develop properly due to corrosive waters. This has devastated aquaculture operations, with hatcheries reporting up to 80% mortality rates in larvae, resulting in millions of dollars in losses and threatening local economies dependent on shellfish harvesting.
Broader Environmental and Human Consequences
Ocean acidification exacerbates biodiversity loss, weakens food webs by impacting foundational species like pteropods (a key food source for salmon and whales), and compounds climate change effects. For humans, it endangers seafood supplies, coastal livelihoods, and carbon sequestration capabilities of oceans, underscoring the need for reduced CO2 emissions to mitigate these cascading problems.