Native agriculture on 'high islands' (e.g. Hawaii) is fascinating. Basically the island is divided radially, (on ridge lines), and the process of agriculture proceeds down from the top with each elevation contributing something unique to the process. At the bottom, encroaching into the ocean with fishponds.

Here is a video, explaining this last bit (requires login):
http://geofflawton.com/videos/fish-ponds-molokai/