PRINCIPAL INVESTIGATOR: Shimi Rii
Co-INVESTIGATORS: Rosanna Alegado, Kawika Winter
PI-CASC Graduate Scholar: Sheldon Rosa
Research Track: Aquaculture

Moʻolelo (Hawaiian oral traditions) speak of Meheanu, the moʻo or reptilian freshwater guardian of Heʻeia Fishpond, who functioned as the bringer of abundance by moving water back and forth to ensure generous output from the pond. To sustain fishpond output, Meheanu controlled food web dynamics by encouraging the well-being of key assets, including ʻamaʻama (striped mullet, Mugil cephalus), a historically, ecologically, and economically important species for Hawaiian aquaculture. Hawaiʻi currently faces serious food insecurity due to a lack of sustainable locally sourced food; however, aquaculture has the potential to meet this need. Hawaiian fishponds are unparalleled examples of effective and resilient place-based food systems.

This study, developed in partnership with Paepae o Heʻeia, the kiaʻi loko iʻa or stewards of Heʻeia Fishpond, employs Loina Welo, or traditional ways of knowing, to address a key question necessary for current restoration: “What are the ʻamaʻama eating now, and where are their prey found?” By understanding the diet of the Hawaiian mullet species, we can better determine how their preferred diet might overlap with the diet of an invasive mullet species (Osteomugil emgeli), which have increased in abundance in Hawaiian estuaries. We will evaluate the diet of both species through DNA analysis, and examine different biomarkers to link the fish with their prey and where they are found within the fishpond. Our study was collaboratively designed with managers to conduct intentional sampling of fish to avoid disrupting their goals for increasing fishery stock. By utilizing samples previously collected from a prior study, and by working with Paepae o Heʻeia staff to collect samples from fish harvested for staff consumption, we employ a “no waste” model for scientific sampling in partnership with the public.

The information generated through this project will guide managers as they decide how to continue restoration and rehabilitation of the fishpond. This project will be co-managed through reciprocal knowledge exchange between researchers, students, managers, and fishpond practitioners. The results of this study will be broadly distributed through an educational journey in the form of field trips mirroring the ʻanae holo, the famous mullet that migrates around the island of Oʻahu. During these field trips, students, practitioners, researchers, and managers will exchange knowledge about how to bring abundance back into their coastal ecosystems. Through this work, we will enhance the capacity for sustainable aquaculture and public resilience in Heʻeia, as well as across the island of Oʻahu and the state of Hawaiʻi.