A Senate committee has advanced a bill that would require a study of traffic, invasive species, harbor space and humpback whale preservation before service could begin. But a similar bill was killed in a House committee that declined to hold a hearing on it.

"There are big concerns," said Sen. Gary Hooser, representing a district on Kaua'i, which is scheduled to start getting the service July 1. "We have a responsibility to our community to look into these matters."

Hooser, vice chairman of the Senate Environment Committee, cited a petition signed by 6,000 people who oppose the Superferry, as well as overwhelming testimony against it from hundreds of residents at meetings held on Kaua'i and Maui.

The ferry would provide the first major alternative to air travel between O'ahu and the Neighbor Islands.

"The people of Hawai'i have to ask, 'Is this something that's good for us?"' said Dick Mayer, a Maui resident who is against the Superferry. "We know that this is potentially very damaging to the environment."

The $235 million Superferry, a four-story catamaran, is scheduled to start daily service between Honolulu and Kaua'i and Maui on July 1. It will carry up to 900 people and 250 cars with one-way fares of $42 per person and $55 per vehicle.

The ferry is expected to arrive in Hawai'i in May after it was launched earlier this year from a Mobile, Ala., shipyard where it was built for use in Hawai'i. A second Superferry would start service to the Big Island in 2009.

The Superferry has withstood both state and federal lawsuits that attempted to force it to conduct an environmental impact statement, but the Senate bill would require an environmental study.

"This company is committed to helping protect our environment in Hawai'i. We want to be here a long time," said Terry O'Halloran, director for business development for the Superferry.

He said the Superferry has gone beyond its requirements to protect the environment.

It will prohibit dirty cars from coming on board, require slower ship speeds in areas with high whale populations and hire two lookout workers on the bridge to spot whales, he said.

Critics of the Superferry claim that little has been done to prevent major traffic jams on at Neighbor Island harbors, and interisland shipping companies have said there isn't enough room for both them and the ferry.

The House bill seeking environmental review of the Superferry died yesterday when the Transportation Committee declined to hold a hearing on it. Committee chairman Rep. Joe Souki, D-8th (Waihe'e, Waiehu, Wailuku), didn't immediately return a phone call seeking comment. Vice chair Rep. Scott Nishimoto, D-21st (Kaimuki, Kapahulu, Diamond Head), said he didn't know why the bill wasn't heard.