We reviewed strategies for detecting invasive species, such as snowflake coral and hookweed, in deep- water habitats of the Northwestern Hawaiian Islands and developed protocols for an invasive species field survey of the Papahānaumokuākea Marine National Monument.
Why We Care
The living coral reef colonies of the Northwestern Hawaiian Islands (NWHI) are a spectacular underwater landscape covering thousands of square miles and composing the majority of coral reefs in the United States. These reefs are some of the healthiest and most undisturbed coral reefs on the planet, hosting more than 7,000 species. Many of these species are rare, threatened, or endangered, and at least one quarter of them are endemic, found nowhere else on Earth.
Invasive species, such as snowflake coral and hookweed, threaten the local organisms in the deeper waters around the NWHI. At greatest risk of being replaced by snowflake coral is black coral, a slower growing coral that is culturally and economically important to the state of Hawaii, bringing in $30 million annually to the local economy. Hookweed is a fast-growing seaweed that threatens edible seaweeds, used for centuries by Hawaiians, and it is extremely difficult to eradicate.
Both snowflake coral and hookweed extend into deep water, and there is little information about invasive species below 30 m. We developed a method for finding invasive species at deeper depths to start filling this information gap.
What We Did
We worked with the Papahanaumokuakea Marine National Monument (PMNM) to detect invasive species in deep-water habitats of the Northwestern Hawaiian Islands (NWHI). The PMNM developed the project objectives to satisfy needs outlined in the Monument Management Plan. The National Marine Fisheries Service’s Coral Reef Ecosystem Division and other local experts helped develop our detection strategies. These strategies use existing datasets and are designed specifically for NWHI.
We completed two field missions to test technologies and strategies. Our products from missions and investigations included:
- Survey protocol for early detection
- Habitat suitability map for an invasive coral
- Assessment of different survey technologies
- GIS datasets identifying locations of invasive species in deep water habitats.
The Papahanaumokuakea Marine National Monument took active steps to mitigate the threats of invasive species to the Northwestern Hawaiian Islands. They developed regulations and protocols to reduce the likelihood of transporting invasive species from source populations in the Main Hawaiian Islands and completed an Alien Species Action Plan to coordinate management.