Sea foam
As the seawater is churned by breaking waves in the surf zone adjacent to the shore, the surfactants under these turbulent conditions trap air, forming persistent bubbles that stick to each other through surface tension.
Sea foam is a global phenomenon,[1] and it varies depending on location and the potential influence of the surrounding marine, freshwater, and/or terrestrial environments.
The dissolved organic matter in the surface water, which can be derived from the natural environment or human-made sources, provides stability to the resulting sea foam.
The high protein and low carbohydrate concentration suggest that sugars originally present in the surrounding mucilage created by algae or plant matter has been quickly consumed by bacteria.
In the Bay of Fundy, high mortality rates of an abundant tube-dwelling amphipod (Corophium volutator) by natural die-offs as well as predation by migrating seabirds contributed to amino sugars released in the surrounding environment and thus, in sea foam.
[1] The presence of sea foam in the marine environment plays a number of ecological roles including providing sources of food and creating habitat.
As a food source, sea foam with a stable composition is more important ecologically, as it is able to persist longer and can transport nutrients within the marine environment.
[3] In the Bay of Fundy for example, a tube-dwelling amphipod, Corophium volutator, can potentially attain 70% of its nutritional requirements from the sugars and amino acids derived from sea foam in its environment.
[6] On the west coast of Cape Peninsula, South Africa, sea foam often occurs in nearshore marine areas with large kelp beds during periods of strong westerly winds.
[2] The ability of sea foam to transport materials is also thought to benefit macroalgal organisms, as macroalgae propagules can be carried to different microenvironments, thus influencing the tidal landscape and contributing to new possible ecological interactions.
[9] As sea foam is a wet environment, it is conducive habitat to algal spores where propagules can attach to the substrate and avoid risk of dissemination.
Some research has shown the presence of various microphytoplanktonic, nanophytoplanktonic, and diatom groups in seafoam; the phytoplankton groups appeared in significantly higher abundance than in sea surface film and the top pelagic zone[7] Naturally occurring sea foam is not inherently toxic; however, it can be exposed to high concentrations of contaminants in the surface microlayer derived from the breakdown of algal blooms, fossil fuel production and transport, and stormwater runoff.
[9] When the impacted sea foam breaks down, toxins from the algae are released into the air causing respiratory issues and occasionally initiating asthma attacks.
P. globosa blooms are initiated in areas of high nutrient availability, often affiliated with coastal locations with a lot of stormwater runoff and eutrophication.
[17] One study showed a much greater abundance of heterotrophic prokaryotes (archaea and bacteria) and cyanobacteria in foam that was generated near a liquified natural gas terminal.
Additionally, higher levels of total organic carbon (TOC) and plankton biomass were recorded in foam generated in close proximity to the terminal.
