Northwest of Kauai and Niihau, a string of tiny islands, shoals and atolls spanning 1,200 miles lies isolated in the middle of the Pacific Ocean.

In the coral reefs of this almost pristine archipelago, predatory fish such as jacks, Hawaiian groupers and sharks are abundant, as are highly sought-after aquarium species.

The Northwestern Hawaiian Islands, also known as Papahanaumokuakea Marine National Monument, are home to more than 7,000 marine species, a quarter of which are found nowhere else on Earth. Encompassing an area of about 139,797 square miles, it is the largest single area dedicated to conservation in the United States, more than 100 times larger than Yosemite National Park and larger than 46 of our 50 states.

Few individuals are able to set foot on the isles or enter its waters.

Now the Waikiki Aquarium will offer a rare glimpse of the monument’s environs and inhabitants with its new Northwestern Hawaiian Islands exhibit opening Thursday, with special keiki activities and educational booths offered from 9 a.m. to 2 p.m.

"The new Northwestern Hawaiian Islands exhibit not only continues our mission to inspire and promote understanding, appreciation and conservation of Pacific marine life, but it also allows visitors to experience some of the rarity that the marine national monument boasts," said aquarium Director Andrew Rossiter. "Many of the species on display are abundant around the Northwestern Hawaiian Islands but are extremely rare or absent around the main Hawaiian Islands."

Among the 25 to 30 species of fish swimming in the 4,400-gallon tank are the masked angelfish, Hawaiian morwong, bandit angelfish and Japanese pygmy angelfish. The exhibit also features 20 species of coral, including table coral, lace coral, irregular rice coral and finger staghorn coral.

Eventually about 225 fish will fill the tank, though they will be introduced gradually in coming months as they complete the quarantine process. The coral will also continue to grow — the table coral, for instance, will branch out horizontally.

"It’s like a garden where you put in the seedlings and in a year all the flowers bloom," said Rossiter. "This is the first phase. It’s going to get gradually better."

TWO INTERACTIVE, touch-screen monitors — one at a child’s height — will provide additional information on the islands’ ecology and biodiversity and the importance of preserving the precious marine ecosystem for future generations.

From the time of its conception, the exhibit took six years to become a reality at a cost of about $350,000, most of it from the aquarium’s fundraising efforts and the past three Ke Kani o Ke Kai summer concerts.

Some funding also came from the National Oceanic and Atmospheric Administration, which collaborated with the aquarium on the project.

The Northwestern Hawaiian Islands were established as a marine national monument in June 2006 and renamed Papahanau-

mokuakea in 2007. In July 2010 they was designated as a mixed World Heritage Site by the United Nations Educational, Scientific and Cultural Organization for its outstanding natural and cultural attributes

Besides being a marine sanctuary for sea life and birds, Papahanaumokuakea has cosmological significance for native Hawaiians.

The aquarium’s goal is to provide realistic, lifelike habitats, according to Rossiter, who himself has never been to Papahanaumokuakea. Eventually the theme of the entire gallery will focus on conservation.

"I’ve always thought aquariums have to be so much more than glass boxes with fish," he said. "They’re not just there to entertain, but ultimately to educate and spur an interest in conservation."

Though isolated, the Northwestern Hawaiian Isles are still prone to marine debris and sea level rise.

With rarely granted permits, Waikiki Aquarium aquarist Richard Klobuchar was part of a team, including Bishop Museum associate zoologist Richard Pyle, that went to the area last year to collect pieces of coral and fish for the exhibit.

The coral reefs, often referred to as the "rain forests of the sea," are vital to maintaining the biological diversity of the oceans; they support and shelter nearly 1 million species of fish, invertebrates and algae.

Klobuchar collected 1- to 2-inch pieces of coral the aquarium then propagated for the new exhibit. The goal was to collect mostly fragments that had already broken off naturally. When possible, the team snorkeled or did shore-based dives instead of diving from a boat.

"We wanted to make the smallest impact possible," he said.

Klobuchar had seen pictures and read about the Northwestern Hawaiian Islands in articles, but to see the place in real life was "amazing," he said, particularly with "the sheer amount of life out there."