Leather Mudweed


Avrainvillea amadelpha


  • Leathery, paddle-shaped blades connected to a compact stem
  • Grows in sand, mud, and coral substrate
  • Pale to dark green in color
  • Can be found with other species growing on it


  • High growth rate
  • Spreads by fragmentation of the fibers in the stem
  • Often found on sandy bottoms, outcompeting sea grasses that feed turtles and other marine species
  • Traps sediment and mud, which can create an anoxic layer
  • Introduction is unknown; first reported in early 1980s
  • A second species, Avrainvillea erecta, has recently been recorded near Honolulu Harbor, with concerns of additional spreading (Wade et al. 2018)


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


  • Oahu: Predominantly in Maunalua Bay
  • Kauai
Mudweed distribution in Maunalua Bay, Oahu

Mudweed distribution in Maunalua Bay, Oahu