Species Information

Red alga
Grateloupia turuturu

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History

• First found on eastern North American shores in 1996 in Narragansett Bay
• Northward spread into Gulf of Maine apparently limited by intolerance of very cold water

Characteristics

• Thin, pink to maroon blades, often with bladelets (pinnae) at base, and a distinctly gelatinous, slippery texture
• Variable growth forms (divided or undivided, varying blade shapes)
• Grows singly, but more typically in clumps of up to 8 individuals
• Grows to full lengths in late summer and early fall, then reduces to crust-like form for overwintering
• Can grow up to 9 ft (3 m)

Habitat

• Shallow water to depths of 6.5 ft (2 m), attached to firm surfaces
• Prefers protected waters such as tidal pools
• Believed to be unable to survive very cold water

Known Distribution in the Northeast

• Boston Harbor to Long Island Sound
• Native to the Pacific Ocean, possibly Japan

Impacts

• Growth pattern and habitat preferences make it a threat to native red algal species, particularly Palmaria palmata and Chondrus crispus
• Broad blades may shade other algae, preventing their growth