Sea Mat (Kelp Encrusting Bryozoan)
Membranipora membranacea
Appearing as a fine, lacy or net-like crust on kelp surfaces, each small zooid has tentacles for filtering plankton. Together, these zooids form a delicate “sheet” that can grow quickly in warmer months. Off Lihou, if you lift a kelp frond during a calm low tide, you may spot the thin, white lace of sea mat colonies coating its surface. You may also find this on kelp fronds washed on to Lihou’s beaches after a storm.
- Habitat: Often found encrusting kelp fronds and other seaweeds in the lower intertidal or subtidal.
- When to See: Mostly in late spring to autumn when kelp is growing well.
- Length: Colonies can cover extensive areas of kelp blades, each tiny zooid ~1 mm