FRENCH FRIGATE SHOALS — Three things were in sight Monday when the crew of the Hi'ialakai launched its big skiff: birds, water and a big rock shaped a little like the double hump of a camel.

More aptly named La Perouse Pinnacle, the rock is a reminder that French Frigate Shoals was once a volcanic island like each of the main Hawaiian Islands.

The Boston Whaler, loaded with scientists, air tanks and even smaller boats, wasted little time in heading to the pinnacle. As it moved closer, the water changed from deep blue to aqua, spotted with yellow and brown reefs, flashing with fish. These reefs are legendary in conservation circles. They are a wonderland of big table corals, which are rarely found elsewhere in the Hawaiian Islands.

And there are crabs and small striped fishes that are so closely tied to these corals that they can't live in places that don't have them.

That's some of the science of this place.

Drifting with a snorkel and mask over sand-floored ravines between coral condominiums, with turtles and sharks and a myriad of bright reef fish — and raising your head above the surface to hear terns and noddies calling, to see great frigate birds in intricate aerial dances with red-footed boobies — that's the poetry of the shoals.

President Theodore Roosevelt recognized the special nature of these islands a century ago and established a bird reserve.

The military fought a war from these islands. The Coast Guard sent out long-range navigation signals to the lonely parts of the Pacific from here. Early trans-Pacific aircraft refueled in these islands.

The Fish and Wildlife Service has held forth protecting the seabirds on these islands. Foreign fishing boats heavily fished some of the waters, and there are continuing battles about whether Hawai'i anglers and commercial boats should be allowed to continue fishing here.

Hawai'i and the Fish and Wildlife Service have banned fishing within their parts of the refuge. And fishing is one of the signal issues in the National Oceanic and Atmospheric Administration's process of designating the place the Northwestern Hawaiian Islands National Marine Sanctuary. A draft environmental impact statement is expected to be released in June, reviewing some of the impacts and alternatives in managing the islands.

But to manage it, people need to know what's going on here. That's the point of this 25-day scientific mission aboard the Hi'ialakai, an NOAA research ship.

Most of the 20 scientists aboard were loaded onto three of the ship's small boats Monday, and they headed off in different directions, some collecting samples of reef fish, some putting radio tags on sharks, some studying corals.

After more than six hours on and under the water, the work continued aboard Hi'ialakai. Some worked on a picnic table on one of the aft decks, storing fin clippings from fishes in tubes for genetic studies later.

In the ship's all-stainless-steel wet lab, others were bagging or bottling clipped-off bits of coral, tentacles of brittle stars, pieces of crabs' legs, and tips of the arms of crown of thorns starfish.

Researcher Iliana Baum said she saw more of the coral-eating starfish at French Frigate Shoals than she has seen before, but probably not enough to represent a threat to the reef. The crown of thorns population can sometimes explode, resulting in severe damage to corals.

"They were mostly juveniles, but if you get big ones, they're like bulldozers on the reef," she said.

Scientists took bits of sea animals that will grow back when possible, but for some reef fishes, catching them to take a fin clipping for DNA analysis is tricky, and they resort to spearing. The researchers have strict limits on how many they can kill, and they try to make the most out of each fish.

State Department of Land and Natural Resources marine scientist Jill Zamzow has manufactured a set of fine mesh nets, and is working on techniques to catch the fishes without killing them, so scientists can clip a tiny piece of fin for genetic testing and then let the fish return to this remarkable reef.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.