Hawaii residents are urged to use the Pest Hotline to promptly report sightings of invasive pests such as snakes, unusually aggressive stinging ants, and illegal or unknown animals. Call 643-PEST (643-7378)
Two similar species of seaweed, both with thick, spiny branches (up to 2 cm in diameter) that can be green, yellow-orange, or red depending on the sunlight.
Grows in thick mats or clumps on reef flats or reef edges up to 20 meters depth
Native to the Philippines, introduced to Kaneohe Bay and Honolulu Harbor in the mid-1970's for aquaculture research into potential use of chemical component (carrageenan)
Harm:
Has a high growth rate. Can double in size in 15-30 days
Spreads mainly by fragmentation (pieces of seaweed float to new locations)
Can overgrow and kill coral by smothering, shading it from sunlight and abrasion
Grows faster than native seaweeds and coral
Causes shifts from diverse coral reef to a seaweed-dominated, low-diversity reef
Changes the bottom structure of the reef, reduces access to crevices and holes
Habitat loss may impact commercial and recreational fisheries
In Hawaii:
Oahu: Currently found only on the Windward Side of Oahu, in Kaneohe Bay
Kauai, Maui, Molokai, Lanai, Kahoolawe, Big Island: Not known to be present
