The environmental group Kahea demanded answers yesterday about the grounding of the work vessel Casitas, which remained aground on the Pearl and Hermes Atoll northern reef yesterday after hitting the coral at 2 a.m. Saturday.

"We have grave concerns about the plight of the wildlife there after exposure to the oil/fuel spill, the impact of this massive ship on the reef, and the future impacts to wildlife from oil and fuels having been released," said Cha Smith, executive director of Kahea, which calls itself the Hawaiian-Environmental Alliance.

Pearl and Hermes, a part of the Hawaiian Islands National Wildlife Refuge, at midsummer is home to pupping Hawaiian monk seals, the hatching season for Hawaiian green sea turtles and fledging Laysan albatross.

The Coast Guard cutter Walnut was scheduled to arrive at the scene tomorrow, after being dispatched from an aids-to-navigation assignment in American Samoa, and the American Marine salvage vessel Quest left Honolulu yesterday for the scene.

BROKEN DEPTH FINDER?

Two significant concerns are the damage the rocking steel ship is causing to the reef and the potential spilling of its 33,000 gallons of diesel fuel and gasoline. No oil was seen during a Coast Guard overflight yesterday, but a sheen was spotted south of the ship for two days after the grounding. The oil had been drifting southwestward across the atoll.

Smith said Kahea learned from a member of the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Council that the Casitas had been sailing with an inoperative depth finder — which could have signaled that it was entering shallow water.

"Why were they under way in the middle of the night, near the reef, without a depth finder?" said Smith. "Stuff is not adding up."

Coast Guard Petty Officer Jennifer Johnson said she could not confirm or deny the information about the depth finder. She said the Coast Guard during the foreseeable future will release no information about the investigation. She would not comment on whether the Casitas was under power when it hit the reef, whether it was suffering any mechanical difficulties, whether it had intended to anchor or had anchored near the wreck site, or other details.

"Nothing is going to come out on that until the investigation is complete and signed off by headquarters," she said.

4-MONTH ASSIGNMENT

The Casitas was on its way from Midway, roughly 90 miles to the west, and had a U.S. Fish and Wildlife Service special-use permit to conduct marine debris removal work first at Pearl and Hermes, and then later at Maro Reef and French Frigate Shoals. The 16 divers — 11 men and 5 women — were on a four-month assignment collecting marine debris from the islands' reefs and beaches. Some are National Oceanic and Atmospheric Administration Fisheries employees and some work for the University of Hawai'i's Joint Institute for Marine and Atmospheric Research.

The ship had been expected to remain at Pearl and Hermes for about a week, said Fish and Wildlife Service spokeswoman Barbara Maxfield.

The divers and the ship's seven-member crew left in small boats after the ship went aground. The Coast Guard reported no injuries to those aboard the ship.

Maxfield said they used small boats that had been on board Casitas to get to North Island, a flat sandy island just inside the northeast side of Pearl and Hermes' barrier reef.

DEBRIEFINGS TO COME

On Sunday, the 23 members traveled nearly 10 miles to Southeast Island, another sandspit, but the largest piece of dry land within the atoll. An NOAA Fisheries research team was on the island conducting monk-seal research.

NOAA's research vessel Oscar Elton Sette, which had been at Midway, was diverted to the scene and picked up the crew members Sunday night. They reached Midway at 6:30 a.m. Monday.

The ship's crew members were flown back to Honolulu on a Coast Guard C-130 aircraft, arriving at 1 a.m. yesterday. NOAA Fisheries spokeswoman Wende Goo said provisions were being made to find housing for divers who had given up their apartments for the expected four-month cruise. She said the crew was being given an opportunity to rest, and then would be debriefed by the Coast Guard.

Johnson and Goo said the crew members would not be allowed to make public statements until they have been interviewed by the Coast Guard.

The removal of the ship and response to any oil spill will be the function of Unified Command, a collaboration between the U.S. Fish and Wildlife Service, the Coast Guard, NOAA Fisheries, the state Department of Health and the ship's representatives.