How could a foam habitat support animal life?

Question

Knowing foam is formed by trapping pockets of gas in a liquid or solid, what could a foam able to support life on an earth-like planet be made of?

This foam ought to be stable enough and large enough to be a natural habitat for life. It could be stable because whatever it's on top of keeps making more or because of its composition as long as it stays long enough to be populated.

By life I don't mean anything that already exists on earth as that would probably be impossible. Though it heavily depends on the foam itself, I imagined a kind of seaweed for the flora. As for animal life, I thought it could be something resembling a mix of a fish and a bird, light and agile enough to move around in the foam. Some animal which couldn't only live in the foam but spends most of its time in it is okay too (I'm thinking like whales who must come out of the water to breathe).

I'm thinking the animals could get their oxygen from the air bubbles foam contains, in fact, it already does on earth but on a much smaller scale. The main problem with sea foam is that it isn't stable and therefore would never be able to support animal life.

This is a follow up question from this primarily opinion-based question about other possible biomes.

Answer 1

A foam generated carefully with the right nutrients and density could (theoretically) be used in a way similar to current hydroponics. Namely, the introduction of the right quantities of water, nutrients, and air, tightly packed together, would create a foam-like substance.

For seeding an earth-like planet with life, a foam-type substance of enough depth could certainly get the ball running. The plants, however, would eventually eat through the foam, so the foam would have to be thick enough to generate enough generations of plants to get the soil to where it would need to be, or would have to be regenerated by machines (with access to the correct nutrients) on a regular basis.

The reason I focus on plant-life growth is (a) it's easier to control, and (b) plants emit the oxygen that animals would would require. I'm taking the perspective that a foam would be enough to sustain a "missing piece" of the circle of life on a new planet - at least for a limited time.

So possible, but tedious and difficult. The "foam" would just be the right balance of nutrients and water, like current hydroponics, but denser and more structured in a more stable way.

Hydroponics has already been useful for growing plants in non-native or otherwise hostile areas. A foam-type substance would provide advantages similar to hydroponics, but with some added benefits. For example, hydroponics is usually done in a clean-room (for many reasons) - one of which being wind. Outside, plants have to interact with wind-flow, and their root systems are important for stability. In a hydroponic system, they have to be carefully maintained and grown as there is only water, and relatively small wind would tumble the plants about. Furthermore, hydroponics has to be carefully managed by humans or robots (AI?) to manage each plant's growth. A foam substance would allow for random seeds to interact with the ground like soil.