This plant-like organism is easy to spot in tide pools due to its brilliant rose color. It often looks like splashes of paint coating the rocks. It grows in very thin sheets with a maximum thickness of one-sixteenth of an inch, or 2 mm. It may dominate a marine area, even growing on the shells of certain marine invertebrates. Patches of coralline algae will have an irregular outline and may resemble lichen in texture.
Coralline algae is an important component in a healthy marine habitat. Not only does it provide an abundant food source for a variety of invertebrates, but it also provides a microhabitat for juvenile urchins, limpets and chitons.
Worldwide, there are over 1,600 species of red coralline algae. It is an extremely hearty species, tolerating depths up to 885 feet (270 m) and both brackish and hypersaline conditions. In some marine areas red algae may completely cover the rocky strata.
This plant may also be known as encrusting coral and rock crust.
This colorful algae is abundant in intertidal and subtidal areas from Alaska to California.
Photo Credit: NOAA.