Gracilaria salicornia, a fast-growing algae was introduced to Hawai’i by researchers in 1974 to foster commercial development of the alga for medical research. The industry never materialized, but the seaweed is pushing out corals and native algae that Hawaii's marine communities depend on for food and shelter.
Volunteers have helped cleared up tons of the invasive algae like Gracilaria salicornia in the past year.

Giant masses of invasive algae, called blooms, are larger and occurring more frequently all over the world. They are appearing in places they have never been, staying longer, and causing devastating damage to native habitats.

Scientists offer several explanations: shipping, which carries algae to new homes in ballast water; global warming, which creates a more nurturing environment for them; and pollution draining into the oceans from coastal development and farmland (farm animals and fertilizers), which provides nutrients.

The algae cleanup in Waikiki is a joint project of the state Department of Land and Natural Resources' Division of Aquatic Resources, University of Hawai’i, the Hawai'i Coral Reef Initiative, The Nature Conservancy, Reef Check and the Waikiki Aquarium.

more about invasive algae blooms