Then:

Back then, in ancient Hawaii, fishponds were used to protect certain fish that were kapu, or forbidden, to catch during some certain months. The fishponds not only protected and raised certain fish, but was also used for religious purposes, too.

Now:

Now, in the modern day Hawaii, some people still use the fishponds for protecting certain fish and religious reasons. But now, we also use the ponds to research and observe these fish.

Other information:

Out of all the fishponds on the island, two of them have been made into national, historical landmarks and are still used by the residents living near them. The two ponds are Keawanui, about 55 acres big, and Ualapue, about 22 acres big.

For more information, visit these sites:

http://www.hawaiiweb.com/

History of Ancient Hawaiian Fishponds

Fishponds of Hawai`i