South Kohala Conservation Action Plan Roi Research Report
This study assessed the costs and benefits of removing Cephalopholis argus (roi), a grouper introduced to Hawaiʻi in the 1950s. The report discusses the effectiveness of using this potential management tool within the suite of conservation actions in response to declines in commercial catches of native fishes and to halt or reduce coral reef degradation in Hawaiʻi.
Subject Tags
- Invasive Species
- Fisheries
- Ecosystem management
Introduction
The South Kohala Conservation Action Plan Roi Research Report presents findings from a long-term study examining the feasibility, cost, and ecological effects of removing invasive roi (Cephalopholis argus), also known as peacock grouper, from coral reefs in South Kohala on Hawaiʻi Island. Conducted by The Nature Conservancy Hawaiʻi Marine Program in partnership with government agencies, researchers, and local fishing communities, the project focused primarily on reefs at Puakō. Through scientific monitoring, experimental fish removals, tagging studies, and community-based spearfishing events, researchers assessed whether targeted roi reduction could improve native reef fish populations and coral reef resilience. Results showed that roi populations could be reduced by more than 90% and maintained through periodic removal efforts, with recolonization occurring slowly over time. The report documents management costs, removal best practices, monitoring protocols, and community engagement outcomes. While no statistically significant improvements in native fish communities were detected during the first two years following removal, the study concludes that roi suppression is operationally feasible and provides valuable information for future invasive species management and coral reef conservation in Hawaiʻi.
Suggested citation
The Nature Conservancy, Hawaiʻi Marine Program. 2013. South Kohala Conservation Action Plan Roi Research Report. The Nature Conservancy Hawai‘i. Honolulu, HI. 44 pp.
TNC Authors
-
Zach Caldwell
Global Dive Safety Officer
The Nature Conservancy
Email: zcaldwell@tnc.org -
Kydd Pollock
Pelagic Conservation Strategy Lead
The Nature Conservancy
Email: kydd.pollock@tnc.org -
Eric Conklin
Marine Science Director, Hawai‘i and Palmyra
The Nature Conservancy
Email: econklin@tnc.org