[4][5][6][7] It is one of thousands of different photosynthetic plankton that freely drift in the photic zone of the ocean, forming the basis of virtually all marine food webs.

This, and the high concentrations caused by continual shedding of their coccoliths makes G. huxleyi blooms easily visible from space.

[14] This species has been an inspiration for James Lovelock's Gaia hypothesis which claims that living organisms collectively self-regulate biogeochemistry and climate at nonrandom metastable states.

[6][15][20][21] During massive blooms (which can cover over 100,000 square kilometers), G. huxleyi cell concentrations can outnumber those of all other species in the region combined, accounting for 75% or more of the total number of photosynthetic plankton in the area.

[14] G. huxleyi blooms regionally act as an important source of calcium carbonate and dimethyl sulfide, the massive production of which can have a significant impact not only on the properties of the surface mixed layer, but also on global climate.

[22] The blooms can be identified through satellite imagery because of the large amount of light back-scattered from the water column, which provides a method to assess their biogeochemical importance on both basin and global scales.

This is due to the mass of coccoliths reflecting the incoming sunlight back out of the water, allowing the extent of G. huxleyi blooms to be distinguished in fine detail.

While multiple scattering can increase light path per unit depth, increasing absorption and solar heating of the water column, G. huxleyi has inspired proposals for geomimesis,[23] because micron-sized air bubbles are specular reflectors, and so in contrast to G. huxleyi, tend to lower the temperature of the upper water column.