Recently, about a half dozen Farrington High School marine science students lowered two cylindrical cages of 300 baby Hawaiian oysters into the murky waters off Sand Island, downstream from Honolulu Harbor’s busy shipping terminals.

For one of those students, Jaynealyce Palakiko, the hope is that this modest batch of dime-sized oysters marks the start of a much larger effort to help filter the pollution flowing toward Mokauea Island, where she used to fish with her dad when she was younger.

“I hope this experiment will help us gather information and see if we can expand this,” the 16-year-old Kalihi native said moments after the cages went in the water last month.

But the oyster study is new. Palakiko will have to wait and see.

For decades now, some U.S. regions have already replenished their fouled streams, estuaries and bays with contaminant-scrubbing oysters, renowned for their ability to help clean up polluted waterways.

But in the nation’s lone island state — where pollution has left fishing and swimming off-limits in some areas due to the potential health hazards — that idea hasn’t taken hold.

Recently, though, a push to reintroduce the small native oysters once abundant in Hawaii has been gaining ground, not just to help clean local waters but also to restore the tiny animals to their original habitats.

Under a pilot program launched earlier this year, researchers have started adding thousands of caged oysters to some of the state’s most polluted waterways, including Pearl Harbor and the notoriously dirty Ala Wai Canal.

“They’re covered in muck. It’s really sad — they’re fuzzy,” Waterkeepers Hawaiian Islands Executive Director Rhiannon Chandler-’Iao said of the first, unlucky batch lowered into the Ala Wai this past April. The nonprofit group examines them weekly.

Waterkeepers is studying how well the native Hawaiian oyster species Dendostrea Sandvicensis adapts to certain spots along the shore.

“A lot of this is so new. We’re learning every time we put oysters in the water,” Chandler-’Iao said.

So far it’s hard to say what impacts the oysters are having, if any, but researchers are confident the tiny bivalves could eventually make a difference in large enough numbers.

The project mirrors similar efforts on the U.S. East Coast, such as the Billion Oyster Project, which has helped improve the water quality in New York Harbor.

“We need to do a lot more as a society than just put out oysters.” — UH Hilo professor Maria Haws

“They’re going to help,” said Maria Haws, a University of Hawaii Hilo professor who directs the school’s Pacific Aquaculture and Coastal Resource Center. The center is partnering with Waterkeepers to cultivate as many as 125,000 juvenile oysters for the restoration project over two years.

Oysters, Haws said, are particularly good at filtering out the sediment and phytoplankton that make Hawaii’s normally clear waters cloudy and murky.

So far, the two groups say, they’ve added more than 60 cages filled with about 10,000 oysters in polluted waters around Oahu. In addition to Pearl Harbor, the Ala Wai and Sand Island, other cages have been placed near the Marine Corps Base in Kaneohe.

“It’s a good start,” Chandler-’Iao said of the groups’ ultimate goal. If the batches start spawning then “we may end up with millions, who knows.”

Waterkeepers, she adds, has secured more grants with private foundations to partner with UH Hilo and UH Manoa’s Sea Grant School to keep its aquaculture efforts going.

But Haws cautioned that the only way to truly fix the water quality is to curb the sources of pollution themselves, such as the thousands of cesspools that dot the islands.

“Even if we had a billion oysters in the water, if we keep putting pollutants in the water we won’t be making any headway,” she said. “We need to do a lot more as a society than just put out oysters.”

The rehabilitation efforts follow the state’s Department of Land and Natural Resources similar feasibility study with oysters in 2017. That study ended after the key official overseeing it moved on to lead the state health department a year later, the department reports.

DLNR referred questions on that study to Bruce Anderson, its former Division of Aquatic Resources administrator who now directs the state Department of Health. Anderson did not respond to a request for comment.

Local Waters Failing Quality Standards

Meanwhile, state health officials say they need to collect more nutrient samples in order to get a better grasp of how Hawaii’s water quality is faring.

The data they do collect, however, already shows the quality could use a lot of improvement.

Out of 108 bodies of water assessed for the 2018 water quality monitoring assessment report, 88 did not meet state quality standards in at least one major pollutant category.

The waters testing positive for high levels of either nutrients or chlorophyll could harm coral and other marine life, according to Myron Honda, a monitoring and analysis supervisor at the health department’s clean water branch.

The waters that test high for bacteria, meanwhile, could potentially harm human health, he added. The department started posting advisories.

“That’s a real problem,” Haws said. “Almost every major water body on the coast — most of them are considered to be impaired or heavily impacted.”

The state further warns the public against fishing in the contaminated waters of the Ala Wai and Pearl Harbor, two primary sites for the Waterkeeper oyster restoration project.

Honda said he thinks the oysters could potentially help such situations.

 “I would like to see the data on (the effectiveness of oysters), because that sounds interesting,” he said Monday.

The cages aim to protect the oysters both from their natural marine predators — as well as any people who might scavenge them. As they scrub Hawaii’s filthiest waters clean, the bivalves aren’t meant to be eaten.

Haws and her UH Hilo team, meanwhile, spawned the oysters added at Sand Island from oysters collected there about a year ago.

The cages lie submerged a stone’s throw from the dock where the Hawaiian sailing canoe replica Hokulea left Oahu in 2014 for its Malama Honua voyage, which aimed to rally greater environmental stewardship around the world.

Members of the Polynesian Voyaging Society, including crew members who sailed on the Malama Honua voyage, will monitor the oyster cages, Chandler-’Iao said.

“It’s actually a learning curve, you know, when you first start taking care of the oysters,” she said. “As soon as they get the rhythm down, then we will be adding more cages and oysters to this site” — possibly as many as 2,000.

“It’s not just that we’re cleaning the water — this is a native species, it should be here,” she said.