(Photo credit: Heʻeia NERR)
Traditional Hawaiian fishponds (loko iʻa) are emerging as a model for climate resilience, according to a study from the University of Hawaiʻi at at Mānoa's Hawaiʻi Institute of Marine Biology (HIMB). The research, published in npj Ocean Sustainability , revealed Indigenous aquaculture systems effectively shield fish populations from the negative impacts of climate change, demonstrating resilience and bolstering local food security.
"Our study is one of the first in academic literature to compare the temperatures between loko iʻa and the surrounding bay and how these temperature differences may be reflected in potential fish productivity," said lead author Annie Innes-Gold, a recent PhD graduate from UH. "We found that although rising water temperature may lead to declines in fish populations, loko iʻa fish populations were more resilient (fish populations did not decline as much as fish populations in the surrounding estuary) to rising water temperatures than those in the surrounding estuary. This result is likely due to the temperature regulation that the loko iʻa receives from freshwater input, both at the surface and below the ground."
The authors found that the combined benefits of fisheries regulations, nutrient flow restoration, and restocking were found to offset some of the potentially negative effects of warming on fish populations and substantially increase short– and long–term estuarine and loko iʻa fish density.
Ancient tech for modern management
Innes-Gold worked with an interdisciplinary team that included university researchers, resource managers and loko iʻa practitioners.
"These findings highlight how important freshwater inputs are as a source of temperature regulation," said Innes-Gold. "They also support the importance of biocultural restoration in terms of enhancing fish populations and increasing social–ecological resilience in a changing climate."
For Hawaiʻi, the findings demonstrate the value that Indigenous knowledge and systems have on guiding modern science.
"Loko iʻa are a system unique to Hawaiʻi, and their restoration can have wide–reaching benefits including cultural preservation, education, healthy ecosystems, food security, and now—from what we found in our study—also climate resilience," said Innes-Gold.
