Conquest of the Intertidal: Impacts of Invasive Algae on Native Algae

Otto, Gracie
Journal Title
Journal ISSN
Volume Title
The intertidal zone is a competitive environment for benthic dwelling organisms. On the south shores of Oʻahu, these zones contain a diverse array of algal species. Native and invasive species compete for space on the intertidal bench. Surveys were carried out by the OPIHI (Our Project in Hawaiʻi’s Intertidal) citizen science program, which collected data on community composition and species abundance at intertidal sites around Oʻahu. This data was analyzed from 2017-2019 at the Ewa Beach site to determine if native algae species cover is reduced by the invasive algae species Acanthophora spicifera, Gracilaria salicornia, and Avrainvilla lacerata. The cover of native algae species was found to be negatively impacted by the increasing cover of the invasive algae species. The species richness analyzed at another site, Diamond Head, determined that both sites have similar community diversity and did not have a significant difference. The increased cover of invasive algae can negatively impact intertidal communities due to the decrease in diversity through habitat modification and displacement of native species. Invasive algae species have the potential to dominate the intertidal community due to faster reproduction methods, resilience, and adaptability to changing environments.
Access Rights
Email if you need this content in ADA-compliant format.