The first Waterkeeper project in Hawai‘i was the restoration of native oysters. Filter feeding bivalves such as oysters can improve water quality by removing harmful pollutants that enter the ocean from wastewater and stormwater. Oysters also remove carbon from the water column and use it to build their shells, underscoring their importance in our changing climate and marine environment.
Over 15,000 native oysters (Dendostrea sandvichensis) produced at the Pacific Aquaculture & Coastal Resources Center at the University of Hawai‘i at Hilo have been out-planted at Joint Base Pearl Harbor-Hickam, the Marine Corps Base at Kane‘ohe Bay, the Hawai'i Yacht Club and the Waikiki Yacht Club in the Ala Wai Harbor, and Honolulu Community College's Marine Education & Training Center at Sand Island. Native oysters have also been restored to Hilo Bay on Hawai'i Island and Nomilu Fishpond on Kaua'i.
The oysters are surviving, growing and now, reproducing. Aggregating native oysters in nearshore areas facilitates their reproduction, which further extends their water quality impact. The project’s goal is to restore this relatively rare and highly important native species to again be abundant and contribute to healthier nearshore waters.
The restoration project is modeled after similar efforts involving oysters for bioremediation. Restoration projects in Hawai'i are made possible with support from private donors including Douglas Emmett, the Chee Family Foundation, the Sangham Foundation, the Van Konynenburg Foundation, the Dreiseszun Family Foundation, and the Omidyar 'Ohana Fund at the Hawai'i Community Foundation.
Many people learn about the attack on Pearl Harbor, but few know the vibrant natural history of the place called Wai Momi (Pearl Waters). Many species of oyster were once abundant there, and in other locations around the islands. Over millennia, oysters have been an important part of the biocultural resources of the Hawaiian Islands. Multiple species of oyster are named in native Hawaiian chants, songs, and legends.
In some areas oysters formed reefs, similar to coral reefs, providing food and shelter for other animals, in addition to providing the ecosystem benefit of water filtration. Agricultural practices, sediment runoff, and other land use changes led to the decline of oyster populations. Today, it is difficult to find many species of native oyster in the wild.
Wai Momi, or Pearl Harbor, was beloved among the people of Leeward O'ahu. The area supported abundant fishponds, vibrant fisheries, and two species of pearl oyster.
In this image, Queen Lili'uokalani, the last reigning monarch of the Hawaiian Islands, is wearing beautiful pearl bracelets on her wrists.
Oysters are known for their ability to improve water clarity by removing pollutants including sediment, bacteria, heavy metals, PCBs, oil, microplastics, carbon, and nutrients from the water column. The first wave of recruits, over 15,000 native oysters, are hard at work underwater across the state.
One year into the restoration, the oysters have inspired land-based efforts by Waterkeepers, including cleanup events, educational presentations, storm drain stenciling projects, microplastics research, and monitoring for wastewater indicators using sucralose and optical brighteners. All of the efforts are aimed at addressing and reducing land-based sources of pollution before they arrive in our nearshore waters.
The restoration efforts inspire many young people to work for clean water, including college and high school students from across the state. Students are hard at work designing new oyster out-planting techniques, recruitment studies, and other efforts to further water quality improvement, under the direction of O‘ahu Waterkeeper and Science Director Dr. Anne Brasher.
With support from the County of Hawai‘i Office of Research and Development, Hilo Bay Waterkeeper and UH Hilo's Pacific Aquaculture & Coastal Resources Center are restoring native oysters and limu (seaweed) to Hilo Bay to remove nitrogen and other nutrients from the water which can lead to algal blooms. An abundance of nitrogen accumulates in nearshore waters as stormwater transports fertilizers and other pollutants from agriculture, cesspools, and leaking wastewater infrastructure. Dr. Karla McDermid is leading the bioremediation efforts using native seaweeds and Dr. Maria Haws is directing efforts with native oysters.
While relatively calm, Hilo Bay is underutilized due to a heavy industrial boom in the mid-1900s that left the waters murky and the shoreline polluted. Adding to the challenge, stormwater, cesspools and antiquated forms of wastewater infrastructure contaminate the groundwater and compromise the area’s swimmable waters.
In conjunction with oyster restoration projects, Waterkeepers engage the community in watershed education to reduce the flow of land-based pollutants towards the nearshore waters.
Crabs like this one sneak into oyster cages as tiny larvae that can grow up eating oysters. Students learn that crabs, like oysters, are an important part of a healthy ecosystem.
Students learn about how the oysters function, and how we can all help them by taking action to improve water quality.
Oysters live in cages to protect them from predators. Help us care for the oysters, clean their cages, and monitor their growth.
You can support our efforts to improve water quality by donating today. Like oysters...no matter how small, every little bit helps. Together, we can ensure fishable, swimmable, drinkable waters for future generations.
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The oysters are kept in cages to protect them from predators. These oysters cannot be eaten, they are for restoration only. Commercial oysters are grow in clean water under strict regulations.
During the Mālama Honua Worldwide Voyage, Thompson witnessed first hand the large-scale Billion Oyster Project in New York Harbor in partnership with Hudson Riverkeeper. Hōkūleʻa's historic first visit to Pearl Harbor one year ago nurtured the connection that the community feels to the area’s natural and cultural history.
The Navy, O‘ahu Waterkeeper, and the Pacific Aquaculture and Coastal Resources Center (“PACRC”) at the University of Hawai‘i at Hilo are restoring native oysters to improve water clarity and quality. This project has deep cultural and historical significance. Native shellfish species were once abundant as expressed through Native Hawaiian chants, songs, and legends. The new project involves the restoration of two species of native shellfish whose populations have declined in modern times: Dendostrea sandvicensis (Hawaiian Oyster) and Pinctada margaritifera (Black-lip Pearl Oyster).
Dedicated to Papahānaumoku (Earth Mother) and the restoration of native oysters at Wai Momi (Pearl Harbor).
Native oysters are filter feeders that remove harmful pollutants including sediment, bacteria, heavy metals, PCBs, oil, microplastics, sunscreen chemicals, and nutrients from the water column.
One adult Hawaiian Oyster (Dendostrea sandvicensis) can filter approximately 20 gallons of water per day. Each ‘ohana of 25 oyster brothers and sisters can filter approximately 500 gallons of water per day. Your donation of $50.00 will support the cost of 25 oysters and the aquapurse that protects them from predation by crabs and other marine animals.
Copyright © 2021 Waiwai Ola Waterkeepers Hawaiian Islands - All Rights Reserved.
Artwork by Solomon Enos.
Photo Credits: Waterkeeper Alliance photos: John Wathen; Oysters photos - Example of Black-lip Pearl Oysters Growing on Lines: Photo by Arthur Read, Smaller Native Hawaiian Oysters: Photo by Dr. Maria Haws; Painting of Queen Lili'uokalani from Ali'i Place: Photo by Rhiannon Chandler-'Iao