HONOLULU -- A new report from a national environmental organization blasts Hawaii's aquaculture industry, saying it damages the environment and is not sustainable. Companies that farm fish in Hawaii dispute the report.

Hawaii has been a testing ground for large-scale industrial fish farming. Currently there are two fish farms here, one off Kona on the Big Island, another off Ewa. More are planned.

Scientists, environmentalists, and native Hawaiians gathered at the Capitol today to urge sustainable fish farming based on more traditional methods. They point to the report by Food and Waterwatch, an environmental organization that says waste from large fish pens damages the bottom. The report also claims the farmed fish spread disease to wild populations.

“The farmed fish are sitting ducks for disease because they are crowded together and there are no predators inside the cage to kill the diseased fish. So diseased fish stay alive a long time and spread pathogens into the water and that infects wild fish.” Said Neil Frazer, a professor at the UH School of Ocean and Earth Science & Technology.

The report says Hawaii aquaculture has failed to demonstrate it is environmentally sustainable. The Pono Aquaculture Alliance wants to see traditional Hawaiian fishpond methods used.

“You have predators that remove the diseased and weak fish to keep the population healthy. You have bottom feeds like crab and shrimp that keep the bottom clean you have fresh water that comes into the pond when fish get parasites they can swim into the intrusion areas and those parasites die,” said Isaac Harp, a proponent of native Hawaiian fish pond farming.

The manager of the state's Aquaculture Development Program supports commercial open-ocean fish farming.

“We see the benefits of open ocean aquaculture and aquaculture in general to provide a safe food source for the population. We know that Hawaii needs to become more self sufficient. We import over 80 percent of our seafood now,” said Todd Low, manager of the state Aquaculture Development Program.