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The Fish Ponds of Molokai

Geoff Lawton visits the Hawaiian Island of Molokai where an 800-year-old traditional fish farming system is being restored. Fish farming has been practiced for centuries in many cultures. The Hawaiians built a sustainable system that worked from the top of the mountain range and ran right down to the base and out to sea.

The Hawaiians built a network of terraced gardens – small spring systems in the upper slope of the island to grow their starch crops of taro. Excess water ran from terrace to terrace, over the most distance to build an abundant food harvesting system. Taro ponds in the upper slopes gathered nutrient and algae and enabled it to flow downhill into smaller collection ponds before being discharged out to sea.


Google Earth aerial view of the 16-acre fish pond in Molokai
that can harvest 400 lbs of fish per acre

Fish are attracted to the nutrient-rich fresh water and with the aid of an extended rock wall, built from coral and lava rocks. These stone walls went out to sea in a great circling arc where gates were built to trap larger fish. Large numbers of fish were able to be harvested using the nutrient run-off from the taro ponds above.

These ancient practices are being reintroduced by Hawaiian custodians eager to rebuild their links with the past.

It’s calculated that each acre of fish pond can harvest 400 lbs of fish. Each pond catchment covers around 16 acres. This is a system that, apart from rock wall maintenance, requires little human input. Mature fish can be harvested at night whilst they wait at the gates to swim back to sea.

Geoff also explains how he taught his students to integrate a food forest at the base of the system to clean dirty runoff water and purify the discharge to the ocean.

2 Comments

  1. I live by Waipio on the Big Island and will be visiting Molokai again Dec.24 thru 27. Wondering if it is possible to visit any of the fishponds.

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