Smothering Seaweed

Smothering Seaweed

Eucheuma sp.                                                                                           



  • Thick, warty, plastic-like, irregularly branching algae growing in tumbleweed-like clumps
  • Varies in color from yellow, green, to brown
  • Grows on reef flats or on sand bed
  • Native to the Philippines


  • High growth rate; can double in size in 15-30 days
  • Spreads by fragmentation
  • Out-competes native alga and coral
  • Grows over coral, shading it from sunlight
  • No native predators in Hawaii
  • Introduced in 1974 for aquaculture with intentions of cultivating for carrageenan, a food-grade thickener


  • Causes shift in ecosystem; what was once coral dominated is now algae dominated with low diversity
  • Habitat loss greatly affects recreational and commercial fisheries