Leather Mudweed

Leather Mudweed (Avrainvillea amadelpha)

Leather mudweed

Photo courtesy of DAR


  • Fan shaped blades attached to single stalk (EOR, 2015)
  • Blades are green in color, usually covered with sand and appear brown (EOR, 2015)


  • Found attached to coral, rocks, or in flat sandy areas with low water motion (EOR, 2015)

Impacts & Concern:

  • High tolerance to environmental extremes (Veazey et al., 2019)
  • Can change community diversity of reefs, lowering fish and invertebrate populations (Veazey et al., 2019)
  • Creates mud layer on top of sand which changes nature of habitat  (UH Botany Dept., 2001)
  • Outcompetes native algae, corals, and seagrasses  (UH Botany Dept., 2001)
leather mudweed

Photo courtesy of DAR


  • First discovered in Hawaiʻi in 1981 (Veazey et al., 2019)
  • Mechanism of introduction is unknown (UH Botany Dept., 2001)


  • Shows low potential to reproduce via small fragmentation, however is highly invasive which raises questions about if fragmentation is the primary form of reproduction (Albright, 2017)

Distribution in Hawaii:

  • Kauai: Present
  • Oʻahu: Present in Diamond Head, Waikīkī, Koko Head, Kahe Point
  • Molokai: Present
  • Lanai: Present
  • Maui: Not found
  • Big Island:  Not found
Mudweed distribution in Maunalua Bay, Oahu

Mudweed distribution in Maunalua Bay, Oahu


  • UH Botany Department (2001) Avrainvillea amadelpha. 5–6. Retrieved March 22, 2021, from https://www.hawaii.edu/reefalgae/invasive_algae/chloro/avrainvillea_amadelpha.htm
  • Eyes of the Reef (EOR) (2015) Leather Mudweed (Avrainvillea amadelpha). Retrieved March 22, 2021, from https://eorhawaii.org/education/marine-invasive-species/leather-mudweed/
  • Veazey, L., Williams, O., & Wade, R. (2019). Present-Day distribution and potential spread of the Invasive green ALGA avrainvillea amadelpha around the MAIN Hawaiian Islands. Retrieved March 22, 2021, from https://www.frontiersin.org/articles/10.3389/fmars.2019.00402/full#B26
  • Albright, S. (2017). A Growing Problem: The Missing Link for Ecological Success by the Invasive Avrainvillea. Retrieved March 22, 2021, from https://core.ac.uk/download/pdf/211323725.pdf