Palmaria palmata vs. Grateloupia turuturu

Grateloupia turuturu and Palmaria palmata in Maine

Grateloupia turuturu is introduced and invasive in Maine. It has been documented as far north as the Damariscotta River in Maine. May be locally abundant, particularly in eutrophic habitats, sheltered marinas, and freshwater-influenced areas on the York and Piscataqua rivers.

Palmaria palmata is a native species common throughout Maine but particularly northern regions in cold, energetic waters and on wave-exposed coast.

Both species are robust red blades found in the low intertidal to subtidally, growing on a variety of substrates such as rock, wood, rope, shell, and epiphytic on other algae.