PRINCIPAL INVESTIGATOR: Robert Toonen
Sea Grant Graduate Fellow: Nākoa Goo
Research Track: Aquaculture

Hawaiian fishponds, or loko iʻa, are generally considered the most advanced of ancient aquaculture systems. By mimicking and enhancing ordinary processes, a strategy called eco-mimicry, ancient Hawaiians were able to maximize estuarine output and sustainable harvests to feed the local population. Populations of baitfish such as nehu and ‘iao have plummeted over the past century, causing concern among managers and local populations alike. Hawaiian estuaries are impacted by threats ranging from introduction of alien species and habitat degradation to coastal development, changes in land use, and population growth, all under the shadow of global warming, that make recovery of the ecologically, economically, and historically important fish species challenging. This project seeks to investigate underlying causes of decline in Hawaiian estuary fishes, starting with documenting historical fishing knowledge and management practices specific to baitfish.

Using oral history interviews of kūpuna (elders), fishpond practitioners, and local fishers, the research team will identify changes in target fish abundance, distribution, and management through time. In addition, they will test hypotheses related to habitat degradation and competition with alien species believed to explain the decline of historically important fish species by exploring related state-wide information on distribution and abundance of baitfish populations, water quality, and diet competition with introduced fish species. The ultimate goal then is to addresses knowledge gaps identified by loko iʻa practitioners as essential to biocultural restoration efforts and co-develop management recommendations and restoration strategies with managers and local groups for important Hawaiian fish species in the face of global warming.