UH Hilo Oysters Will Clean Water at Sand Island

UH-Hilo Aquaculture tanks. PC: DOA

Water clarity and quality at Sand Island, Honolulu will be improved using a natural resource — oysters.

Baskets of native oysters cultured at the University of Hawaiʻi at Hilo Pacific Aquaculture and Coastal Resource Center were placed in the water at Honolulu Community College’s Marine Education Training Center (METC) and the Polynesian Voyaging Society’s mooring area during ceremonies in October, according to a UH press release.

Students from Farrington High School‘s marine science classes contributed to the project by measuring and then placing the oysters in the water prior to a ceremonial blessing, the release said. Hawaiian prayer, chants and other protocols were also offered.

The oysters filter between 20 and 45 gallons of water per day, depending on their size, removing harmful pollutants including sediment, bacteria, heavy metals, PCBs (a group of toxic, man-made chemicals), oil, microplastics, sunscreen chemicals and nutrients from the water column, which improves water clarity and quality. This is the sixth Oʻahu location utilizing native oysters for water quality improvement.

“We also have [oysters] in Hilo Bay, which was the first place in Hawaiʻi where this was attempted starting in 2011,” said Maria Haws, director of the Pacific Aquaculture and Coastal Resource Center. “All of these are pilot efforts to obtain more data on growth and survival. The results have been good so far, so we’ll be expanding from 10,000 now out in the field to a total of 14,000 next month. Maui also has a site where we will use triploid Pacific Oysters with outplanting in December.”