He ala ʻae kai – The path near the sea: Climate inflictions upon intertidal

Levels of rocky outcrops show shades of color, dropping off to the churning ocean.
The black zone or “splash zone” spans from the mid to upper extent of the intertidal zone, where basalt rock is typically exposed to air. The pink zone encompasses the lower extent of the intertidal, where basalt rock is covered in crustose coralline algae. (Photo: LKapono)

The Hawaiian intertidal zone is a place of cultural practice, food harvesting, recreation, and a basic necessity for access to the ocean and its resources. The intertidal zone also bears the brunt of wave action during storms. Climate change projections suggest there will be a northward shift of large storms and hurricanes, increasing the chance of landfall upon the Hawaiian islands. With elevated sea level, larger wave runup is projected along the coast under both normal conditions and extreme events. No study to date has assessed the combined impacts of increased flooding and wave run-up upon the resources within Hawaiʻi’s rocky intertidal zone.

In the Hawaiian Islands intertidal zone, three limpet species (Cellana exarata, Cellana sandwicensis, and Cellana talcosa) collectively known as ʻOpihi, represent the majority of our shellfish consumption and are a vital resource for commercial and noncommercial near-shore fisheries. ʻOpihi provide significant ecosystem services by mitigating the overgrowth of many algal species that would otherwise smother the intertidal zone and its other inhabitants. Long term changes in seasonal and annual weather patterns coupled with elevated water levels will cause the intertidal zone to migrate to higher elevations. Unfortunately, we still lack adequate characterization and understanding of the potential spatial and temporal changes in the available habitat for ʻOpihi; or modeled shifts in future ʻOpihi habitat due to climate change. In 2008, Nā Maka Onaona (NMO), led by Pelika Andrade and Kim Morishige, partnered with the Kaʻūpūlehu community to conduct monthly ʻOpihi monitoring at the Kalaemanō shoreline. Kalaemanō is a southwest facing shoreline in the ʻahupuaʻa of Kaʻūpulehu, and located in the moku of Kona, Hawaiʻi.

Students sample shells on steep rocks with water churning below.
Past Na Kilo ʻĀina interns assist in monthly PACC surveys. They are counting ʻOpihi in both black and pink zones. (Photo: LKapono)

Along with programs and partnering agencies, NMO has created a unique historical dataset that spans over a decade and has currently developed a survey method known as Productivity and Carrying Capacity (PACC) survey. PACC will be implemented as the primary methodology to identify ʻopihi habitat on the shoreline. Sea level rise predictions will be overlaid upon the mapped habitat to better understand where these threatened boundaries exist. Climate scientist Dr. Haunani Kane and the UHH MEGA lab are highly involved in the construction and creation of the sea level rise maps and projections.

The main objectives of this collaborative project are to 1) Assess seasonal shifts in intertidal resources from monthly surveys, and 2) Predict long-term impacts of sea level rise upon the intertidal habitat. The results from this project will help create recommendations for sustainable harvesting practices and management measures using an indicator-based approach. Understanding how these habitats shift both seasonally and under a changing climate will contribute to how we maintain and care for the existing areas.


A collaborative effort

Lauren Kapono writes: I am very fortunate to be able to collaborate with such innovative scientists and research conducting community members. NMO led by Pelika Andrade has a research team with a diverse skill set. From ridge to reef, this organization has created relationships with community members that are inspirational. Invested communities such as Kaʻūpūlehu, ensuring that their resources are healthy, resilient, and able to sustain the collective into the future. Aunty Leinaʻala Keakealani Lightner is the director of the Ka‘ūpūlehu Interpretive Center at Kalaemanō and representative of Kaʻūpūlehu community. She has always believed in the research conducted by her community and supports the knowledge to better understand the tendship for their natural resources. Looking to elevate the story of these community driven projects, the expertise of the MEGA lab at UHH was sought out. Dr. John Burns and Dr. Haunani Kane are highly skilled in technological advancements and have a lot of experience working with grassroots projects. It is an honor to be able to collectively elevate this story of place in hopes Hawaiʻi can be an example to other island nations.





John Burns
Assistant Professor of Marine Science, UH Hilo


Lauren Kapono
Tropical Conservation Biology & Environmental Science, UH Hilo
Haunani Kane
Post-doctoral Researcher, Marine Science Department, UH Hilo