Plankton blooms occur when conditions such as increased nutrients, warm temperatures, and ample sunlight cause rapid multiplication of plankton populations, particularly phytoplankton. These plankton can be transported from open waters toward the shore by wind, waves, and currents.
As they get trapped in the surf zone, continuous wave action eventually deposits them on the beach. Once ashore, plankton are exposed to harsh conditions like direct sunlight and drying winds, which are not conducive to their survival, leading to their death. The decomposition process begins, with bacteria and other microorganisms breaking down the organic matter, releasing proteins, lipids, and other organic substances into the water. These organic compounds reduce the surface tension of water, making it easier for bubbles to form.
The constant agitation of the water by waves and wind mixes air with the water, creating bubbles. The organic compounds act as surfactants, stabilizing these bubbles and allowing them to accumulate. As more bubbles form and stabilize, they gather into clumps, resulting in the formation of sea foam. This natural process is a common phenomenon observed in coastal ecosystems around the world.
The bubbles that form sea foam are influenced by various factors, including the composition of the water and the presence of organic compounds. These bubbles can vary in size, from microscopic to several millimeters in diameter, depending on the amount of organic material and the intensity of wave action.
Their stability is primarily due to organic compounds, such as proteins and lipids, released from decomposed plankton. These compounds act as surfactants, reducing the surface tension of the water and preventing the bubbles from popping quickly, allowing them to last longer. The bubbles are composed mainly of water with dissolved salts and minerals from the ocean, and the organic compounds create a thin film around each bubble, stabilizing them. This reduction in surface tension means less energy is required to create new bubbles when air is mixed with the water by wave action.
Typically spherical due to even surface tension, bubbles can take on polyhedral shapes when packed closely together. Their behavior varies with environmental conditions, such as wind blowing foam ashore or wave action causing it to pile up or spread out. The foam appears white because the bubbles scatter light, reflecting and refracting it in all directions.
The density and texture of sea foam can also vary, appearing denser and thicker when small bubbles are tightly packed, or lighter and more airy when larger bubbles are more spread out. The interplay between environmental factors and the presence of surfactants determines the foam’s stability, density, and texture.