Like their Polynesian forebears, Hawaiians were among the first aquaculturists on the planet. Scientists still marvel at the ways they used ponds along the shoreline to stock and harvest fish. There are actually two different types of ancient fish ponds (or loko i‘a). Closed ponds, located inland in shallow lava pools known as anchialine ponds, were fed by freshwater springs as well as the ocean. Open ponds used rock walls as a barrier to the ocean and sluice gates that connected the ponds to the ocean, leaving just enough room for juvenile fish to swim in at high tide while keeping the bigger, fatter fish from swimming out. Generally, the Hawaiians kept and raised mullet, milkfish, and shrimp in these open ponds; juvenile manini, papio, eels, and barracuda occasionally found their way in, too.

The seven ponds of the Kalahuipuaa Fish Ponds, just south of the Mauna Lani Bay Hotel & Bungalows ([tel] 808/885-6622), include examples of both types of ponds; they’re still stocked with mullet and milkfish that are rotated through ponds as they grow. The trail through the ponds is marked with interpretive signs, as are the sprawling Kuualii and Kahapapa Fish Ponds, just behind the thin crescent of Anaehoomalu Beach in front of the Waikoloa Beach Marriott Resort & Spa ([tel] 808/886-6789). They’re not as actively managed, but you can spot fish of all sizes in them.