Smothering Seaweed

Smothering Seaweed (Kappaphycus alvarezii and Eucheuma spp.)

Eucheuma spp.

Photo courtesy of DAR

Eucheuma spp.

Description:

  • Thick intertwined branches that form mats (CABI, 2019)
  • Branches are cylindrical axes with spines (CABI, 2019)

Habitat:

  • Typical found in shallow, subtidal reef flats (Russell, 1983)

Impacts & Concern:

  • High growth rate and reproduces through fragmentation (Russell, 1983)
  • Shades out and smothers corals (Russell, 1983)

Introduction:

  • Introduced from the Philippines to Kāne‘ohe Bay in 1974 for scientific experiments (Russell, 1983)

Distribution in Hawaii:

  • Kauai: Unknown
  • O‘ahu: Present in Kāne‘ohe Bay (CABI, 2019)
  • Molokai: Unknown
  • Lanai: Unknown
  • Maui: Unknown
  • Big Island: Unknown

Related AIS Team Management Projects:

  • Urchin outplanting efforts in Kāne‘ohe Bay

References:

  • CABI. (2019). Eucheuma Spp. Data sheet. Retrieved March 22, 2021, from https://www.cabi.org/isc/datasheet/102037#toenvironments
  • Russell, D. (1983). Ecology of the Imported Red Seaweed Eucheuma striatum Schmitz on Coconut Island, Oahu, Hawaii! Retrieved March 22, 2021, from https://core.ac.uk/download/pdf/5093462.pdf

 

Kappaphycus alvarezii

Kappaphycus alvarezii

Photo courtesy of DAR

Description:

  • Coarse branches in irregular patterns (UH Manoa, 2001)
  • Shiny green to orange-yellow in color (UH Manoa, 2001)
  • Intertwined branches to form thick mats (UH Manoa, 2001)

Habitat:

  • Typically found on patch reefs in shallow water (Rodgers & Cox, 1999)
  • Inhabits sand-covered grooves in reef (Rodgers & Cox, 1999)

Impacts & Concern:

  • High growth rate and vegetative regeneration makes it quick to spread (UH Manoa, 2001)
  • Can double in size in 15-30 days (UH Manoa, 2001)
  • Shadows and smothers native corals (UH Manoa, 2001)

Introduction:

  • Introduced to Kāne‘ohe Bay for commercial cultivation in 1974 (Rodgers & Cox, 1999)

Distribution in Hawaii:

  • Kauai: Unknown
  • Oʻahu: Present in Kāne‘ohe Bay (Rodgers & Cox, 1999)
  • Molokai: Unknown
  • Lanai: Unknown
  • Maui: Unknown
  • Big Island: Unknown

References:

  • UH Manoa. (2001). Kappaphycus alvarezii Fact Sheet. Retrieved March 05, 2021, from https://www.hawaii.edu/reefalgae/invasive_algae/pdf%20files/kappaphycus_alvarezii.pdf
  • Rodgers, K., & Cox, E. (1999). Rate of Spread of Introduced Rhodophytes Kappaphycus alvarezii. Retrieved March 05, 2021, from https://scholarspace.manoa.hawaii.edu/handle/10125/1904

Kappa_KaneoheBay2-with-pics