ABOARD HI'IALAKAI —Sleepy-eyed scientists hauled computers, dive gear, instruments and other equipment just after dawn yesterday across the dusty dock at Snug Harbor, where the NOAA research ship Hi'ialakai ties up.

The ship, with 20 marine scientists aboard, sailed to Pearl Harbor to fuel, and left at sunset for a 25-day expedition into the Northwestern Hawaiian Islands and south to Johnston Atoll.

It is a trip with several missions.

The researchers gathered at 7:40 a.m. in the ship's mess, where chief scientist Randy Kosaki gave them a briefing on the importance of the overall mission and the importance of being careful not to damage the resource they come to study.

"This is a very fragile place," he said.

Kosaki, a marine biologist and research coordinator with the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve, said this particular mission is of special importance because it will probe the links between the Hawaiian archipelago and Johnston Atoll, which marine biologists believe is a stepping stone for fish, corals and other forms of marine life from the southern Pacific to Hawai'i.

"This is new for us. We are actually going outside of our jurisdiction to Johnston Atoll. It is a key spot with a lot of explanation about the origins of our marine life," he said.

Kosaki is a regular to the Northwestern Hawaiian Islands, having sailed there both on research ships and aboard the Hawaiian voyaging canoe Hokule'a.

He also conducted research at Johnston 15 years ago, discovering and naming a new species of angel fish. On this visit, he hopes to collect a few of the fish alive for display at the Waikiki Aquarium.

These scientists are operating under several permits, including ones from the Fish and Wildlife Refuge, which operates wildlife refuges in both the Northwestern Hawaiian Islands and Johnston Atoll, and from the state Department of Land and Natural Resources, which controls the waters from shore to three miles out.

The scientists work together on each other's missions when they can. Their expertise ranges greatly from basic biology to complex genetic sampling. Their interests cover fish, corals, lobsters and other crustaceans.

Some of the most physically dangerous research on this mission will involve catching sharks and other predators, and handling them while radio tags are inserted surgically.

The radios will be used to track the fish — using microphones on the ocean floor — to find out how much they move around.

The ship was expected late today to reach its first stop, the rocky island of Nihoa, where it will spend two days. From there, it will travel to the French Frigate Shoals, the Gardner Pinnacles and Johnston Atoll.

Scientists will try to answer a question that has been at the heart of the discussion about controlling fishing in the Northwestern Hawaiian Islands.

Some people suggest that these islands are critical as a refuge because they serve as a source of new fish, lobster and other species for the main islands.

If true, that means heavily overfishing the waters around Hawai'i's main islands might not be critical because there will always be a source of new fish to the northwest.

"The popular notion is that the Northwestern Hawaiian Islands rains larvae on the main Hawaiian Islands," Kosaki said. "But if the opposite is true, we've got a problem. That would mean we need to protect the resources in both places."

Genetic researchers on the voyage will study the relationships between species on individual islands, and their kinship to the same species on other islands. The research will help determine isolation.

The importance of the research is this: Say a disease or natural disaster severely damages the corals on one island. If there's a lot of movement of larvae from one island to another, the island's reefs can expect help from their neighbors to recover.

But, if there isn't much transport — if islands are isolated genetically — then an island would have to depend on its own resources to survive.

It's going to be an interesting trip.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.