A new land-based salmon farm, described by industry groups as among the world's largest, is raising millions of the healthy popular fish in giant warehouses about 30 miles southwest of Miami.

The subtropical location for the farmed salmon, which love cold northern waters, is unique in the world. The company, Atlantic Sapphire, pulls cold water from underground and keeps it at 59 degrees Fahrenheit in what it calls a bluehouse -- a greenhouse for fish.

Norwegian entrepreneur Johan Andreassen built the farm in Homestead, Fla., over the past two years, relying on a steady supply of fresh and salt water from underground aquifers, he said. That's because salmon in the wild lay eggs in freshwater rivers, and the young fish swim to salt water to grow.

Ultimately, the company wants to supply a sizable portion of the U.S. salmon market at a time when more Americans are turning to healthy fish in their diets.