The 7-1 council vote means the councils on Kaua'i, Maui and the Big Island have all called for more study before the ferry begins service.

The Superferry's 340-foot-long vessels would offer three-hour crossings from O'ahu to Kahului Harbor on Maui and Nawiliwili Harbor on Kaua'i starting in July.

A second vessel will enter service in 2009, expanding routes to Kawaihae on the Big Island.

The state is not planning an environmental impact statement for the project, and Hawai'i Superferry Chief Executive Officer John Garibaldi said his company is already doing many of the studies that would go into an EIS.

Garibaldi said his company has done traffic studies, developed a whale avoidance policy to protect marine mammals, and worked with environmental experts to avoid spreading invasive species.

"We're doing things already, being an environmentally friendly and conscientous company," he said. "We continue to talk with council members, we continue to talk with communities and to get feedback from experts in their fields throughout the state of Hawai'i."

The first superferry vessel will be delivered soon, and the second vessel is already under construction, he said.

Among those favoring an environmental impact statement for the project was Karen Rosen, who cited the financial risk to taxpayers from the project.

The state is spending $40 million for barge, ramp and apron systems to be installed at the four Superferry ports, including a barge for Kawaihae.

The federal government has also approved a $140 million loan guarantee for the company to help finance the cost of building the vessels. Safety and social welfare issues are also raised by the superferry, which is expected to transport the U.S. Army's armored Stryker vehicles to the Big Island for training, Rosen warned.

Rosen suggested homeless people might also be transported interisland on the vessels, "overburdening neighbor island social services."

Gunner Mench, a Kawaihae business owner, opposed the council resolution, calling it an example of "one agency of our government not talking to another."

Mench argued that an environmental impact statement is already planned for Kawaihae Harbor in connection with plans to update the harbor master plan. Since there are already plans for an impact statement, Mench said demanding another report on the superferry "is essentially redundant."

The council resolution warns that Kawaihae Harbor is already under pressure from the steadily increasing volumes of cargo traffic at the port, with increasing numbers of vessels vying for limited harbor space. Superferry service may trigger a reduction in inter-island barge service by tying up space now used by Young Brothers, Ltd.

The resolution also raises concern that the superferry could spread invasive species as cars and other cargo that are transported interisland, and could also kill the whales by striking them along the superferry route.

"It seems quite evident that Hawai'i Superferry will have a tremendous impact on many aspects of our environment, and the questions regarding additional tax revenue that will be needed to help support this venture need to be answered," said Kona resident Jeff Sacher in written testimony submitted to the council.

The state and superferry officials have said they will scrutinize cargo to be sure the service does not help spread invasive species. State and federal authorities determined the ferry was not required to conduct an environmental assessment, and legal challenges arguing for an environmental review have been rejected by state and federal courts.

However, appeals of those rulings are expected.