This is a herbivorous bottom dweller (up to 370 m deep), which feeds on seagrasses in the genera Zostera and Posidonia.
They are found in tropical to temperate waters, often associated with sea grass beds (e.g. Posidonia and Zostera).
This species occurs at depths of 2 to 100 metres It attaches itself to rocks and overhangs, or among Posidonia.
In 2006 a huge clonal colony of Posidonia oceanica, was discovered south of the island of Ibiza.
This actually reduces the pollution in those areas, as the caulerpa consumes it: In an eight year study of Caulerpa beds in the French Bay of Menton, it was found that the alga reduced pollution and aided in the recovery of native Posidonia seagrass.