For centuries, loko iʻa, or fishponds, were a vital part of the Native Hawaiian food system, connecting freshwater sources to the ocean, using rock-wall enclosures to raise and eventually harvest fish. In recent decades, there has been a resurgence of this indigenous way of aquafarming. Kai Piha: Nā Loko Iʻa looks at how four fishponds on Oʻahu are being restored.