An aragonite sea is a marine environment or geological setting where aragonite, a mineral form of calcium carbonate (CaCO3), is a predominant or significant component of the sediment, structures, or formations. In such environments, the mineral aragonite can play a key role in shaping the characteristics of the sea floor and the overall ecosystem.
Key points about aragonite seas include:
- Coral Reefs: Aragonite seas are often associated with coral reef ecosystems. Coral reefs are composed of calcium carbonate structures primarily built by coral organisms. Many reef-building corals, such as stony corals, use aragonite to construct their skeletons.
- Aragonite Skeletons: Corals and other marine organisms that build calcium carbonate structures often use either aragonite or calcite to create their skeletons. The choice between these minerals is influenced by factors such as water chemistry, temperature, and other environmental conditions.
- Aragonite Stability: Aragonite is more soluble than calcite in slightly acidic waters, making it particularly sensitive to ocean acidification, which occurs when the ocean absorbs excess carbon dioxide from the atmosphere. Ocean acidification can affect the ability of marine organisms to build and maintain their aragonite-based structures.
- Vulnerability: Coral reefs and other aragonite-based ecosystems are vulnerable to the effects of climate change, including rising sea temperatures and ocean acidification. These factors can impact the health and survival of corals and other organisms that rely on aragonite for their skeletal structures.
- Sediment Composition: In some marine environments, the sediment on the sea floor can also contain aragonite, particularly in areas where calcium carbonate production exceeds dissolution. These sediments contribute to the overall composition and character of the sea floor.
- Carbonate Compensation Depth: The carbonate compensation depth (CCD) is the depth in the ocean at which the rate of calcium carbonate dissolution matches its rate of production. Aragonite seas may have specific CCD levels that influence the distribution of calcium carbonate minerals in the water column and on the sea floor.