About 20 years ago an endangered species of native wading bird took up residence on a small island in the Hawaii Kai marina.

But has this islet, called Rim Island No. 2, been a beneficial breeding ground for the species, the Hawaiian stilt also known as aeo? Or is it an ecological trap that hurts population growth because babies of the slender black-and-white birds hatched on the island starve to death?

Both are contentions by two groups with long-held opposing views for how the 5-acre island should be used.

And now these arguments are being dredged up and renewed in an ongoing federal and state regulatory process as the operator of the 13-mile waterway in East Honolulu tries to resolve a languishing problem of where to dispose of sediment that has made the marina too shallow in several places.

Rim Island No. 2 was meant to be a receptacle for sediment occasionally removed from the waterway.

Jim Dittmar, an environmental consultant whose home fronts the marina, said filling in the island will destroy what ironically became the only piece of wetland left in an area where a giant fishery and wetland called Kuapa Pond was turned into the marina community more than 50 years ago.

“Why can’t Rim Island No. 2 be saved as a natural preserve and an endangered species habitat?” he asked.

Dittmar said the association of residential and commercial property owners that manages the marina is seeking to fill the island with dredged sediment because it’s the cheapest place to put the material.

The Hawaii Kai Marina Community Association did not respond to a request to discuss its $5 million dredging project that has been stalled for two years.

The association began dredging the waterway in 2013 after obtaining a permit from the U.S. Army Corps of Engineers.

Up to an estimated 121,900 cubic yards of sediment — an amount that could fill roughly 7,000 dump trucks — was to be removed from five areas, including the marina’s main entrance channel.

The Army Corps approved five disposal sites. Most of the material was intended for two sites, a deep ocean repository and a bank of the marina where a yacht club has long been planned. But using these two sites has been problematic, and pushed the marina association to seek alternatives after removing only about 23,000 cubic yards of material.

Making things worse, about 15,000 cubic yards of sediment was illegally dumped in Waianae on land owned by the head of a trucking company retained by the dredging project’s contractor, American Marine Corp.

The trucking firm, SER Silva Equipment, owned by Sandra Silva, didn’t have permits to deposit the fill. The city fined Silva and placed a lien on her property. The deposits were discovered after one of Silva’s trucks spilled the sludgelike material on the H-1 freeway in Aiea in August 2013.

The marina association said it was American Marine’s responsibility to ensure that disposal measures followed what was approved in its permit.

Marina operators in late 2013 applied to modify their federal permit to add two more disposal sites — the private PVT landfill in Nanakuli and the nearby city landfill at Waimanalo Gulch — estimating that only 30,000 cubic yards of sediment was left to be dredged.

But plans to use the landfills didn’t pan out. So the marina association sought to add another pair of disposal sites, a Kahuku ranch and Rim Island No. 2.

In July the Army Corps approved Pohaku Nui Ranch as a disposal site, allowing up to 20,000 cubic yards for leveling out a pasture.

The move, however, to add Rim Island No. 2 has stirred up old controversy.

The island was created with a sister island, Rim Island No. 1, in 1960 by Hawaii Kai’s developer, Henry Kaiser, as doughnut-shaped berms to be filled during future marina dredging maintenance.

In 1996 most of the 1.4-acre Rim Island No. 1 and a bit of the second island were filled with 53,600 cubic yards of sediment.

Rim Island No. 1 was landscaped and serves as a picnic area for marina users, though a small depression is still permitted to take 6,000 cubic yards of sediment.

The deposits in 1996 created a mudflat and shallow water within much of Rim Island No. 2 that attracted Hawaiian stilts, establishing a federally recognized and protected habitat for the birds, which nest in the island’s vegetated banks.

Subsequent plans in 2002 to dredge and deposit sediment on Rim Island No. 2 triggered objections from wildlife supporters who called the island the only aeo nesting ground between Honolulu Airport and Kaneohe protected from predators that include cats, dogs and rats.

At that time a marina association representative, Reggie David, claimed that insufficient food existed on the island to support chicks growing to fledglings and that the species would be better off if nesting on the site were discouraged.

Phil Bruner, a biology professor and director of the Museum of Natural History at Brigham Young Univer­sity-Hawaii, responded in comments submitted to the Army Corps in 2003, calling David’s claim unsupported by any qualitative data.

The Hawaii Audubon Society wrote to the Army Corps, asking that the plan be denied or that public hearings be held.

“The biggest impediments to the recovery of the endangered Hawaiian stilt are the loss of wetland habitat and predation by alien mammals,” Linda Paul, the group’s executive director for aquatics, wrote to the Army Corps in 2005.

The state Department of Land and Natural Resources and the U.S. Fish and Wildlife Service also expressed concerns over the stilts at that time, and the 2002 permit application wasn’t approved.

Now, as part of the new effort to fill in Rim Island No. 2 with up to 31,300 cubic yards of sediment that would raise the elevation of the island to 14 feet above mean sea level, the marina association is trying to again establish that the island is detrimental to Hawaiian stilts.

“Any stilts that nest on this island do not contribute to the population genes as none of their offspring survive,” Robert Clark, marina association president, wrote to the Army Corps in February.

Clark wrote that based on years of marina security staff monitoring and numerous surveys by a qualified biologist, aeo have never raised chicks to fledglings because the baby birds don’t have enough food to eat. “They likely starve to death,” he wrote. “In essence the island is a biological sink for nesting stilt.”

Adult aeo don’t feed their chicks, which can walk and forage for their own food until they can fly.

J. Michael Reed, a biology professor at Tufts University who has published research on Hawaiian stilts, said generally that sites that attract breeding aeo but lack food to support young birds to the fledgling stage can be ecological traps worth eliminating. He added that making such a determination requires scientific data.

“Has anyone banded chicks at the site and noted their lack of fledgling? Have they found dead, emaciated chicks at the site? If not, then it seems like speculation,” he said in an email.

Aaron Nadig, a Fish and Wildlife official, recommended to the Army Corps in an October letter that aeo would benefit from filling Rim Island No. 2, based on what Nadig said were Army Corps surveys over the past year that documented three nests from which no fledgling birds were raised.

“Nest failures indicate the habitat feature at (Rim Island No. 2) is not conducive to species fecundity and can be referred to as a ‘biological sink’ as reproductive energy and genes are wasted at a site that does not support successful reproduction,” Nadig wrote. “While the proposed action may affect the Hawaiian stilt temporarily with the immediate loss of habitat, the permanent loss of the attractive nuisance would not adversely affect the species.”

DLNR has concurred with Fish and Wildlife’s assessment, but also said the project to fill the island could be done so that Hawaiian stilt habitat is maintained or enhanced.

Bruner of BYUH said food for the stilts, primarily invertebrates, can vary from year to year, so he questions whether anyone knows with certainty whether any chicks have ever survived.

“It’s a valuable site,” he said of the island. “It might fluctuate year to year as a valuable reproductive site for the stilt.”

Dittmar, the environmental consultant who lives along the marina, contends that he has seen one chick raised. He also said the marina association hasn’t addressed aeo impacts in an environmental assessment for the dredging permit. The assessment said the project will have no impact on the Hawaiian stilt “because dredged material will not be deposited on Rim Island 2.”