Hawaiian kupuna Henry Chang Wo Jr. sounded the alarm over vanishing limu and led efforts to protect and restore seaweed beds and the ecosystems they anchor.

Known fondly as “Uncle Henry,” the lanky Ewa Beach resident crisscrossed the islands giving “show and tell” sessions, educating thousands of keiki and adults on the care, uses and role of limu in the Hawaiian way of life. He died of lung cancer at age 74 on Sept. 19 and will be remembered at a service on Oct. 29.

“He was a living treasure,” said Alan Murakami, director of community engagement for the Native Hawaiian Legal Corp. “There are not a lot of people left like that. He spoke from the heart, quietly, humbly, with passion. It made you want to listen.”

Born in Honolulu on May 19, 1941, Chang Wo grew up in Halawa and would go to the Ewa shoreline with his family every weekend to fish and pick limu, according to his niece, Zsanette “Sugar” Alfafara-Pires. His mother and grandmother taught him to gather the different species carefully, without disturbing the roots, back when native seaweed was so plentiful it reached up onto the sand. He called the area “The House of Limu.”

In later years, he was dismayed to see native seaweeds disappearing after sugarcane fields gave way to housing development in the area. He worked to remove invasive species and replant native varieties, anchoring the willowy algae with rocks. When overzealous harvesters yanked that limu up by the roots, he spearheaded a successful campaign to get the state Department of Land and Natural Resources to set aside a “no pick zone” to allow the limu to regenerate at Ewa Beach. The Limu Management Area became part of Hawaii law effective Jan. 1, 2007.

A diver and fisherman, Chang Wo was fearless in protecting his ocean heritage. He challenged Haseko (Ewa) Inc. before the Board of Land and Natural Resources when the developer sought permission to bulldoze a berm along the sandy beach in front of Kaloi Gulch to allow storm runoff to flow directly into the ocean at Oneula Beach Park. He was concerned that pollutants such as motor oil and pesticides would kill the limu. The permit was granted, but the case is on appeal.

“Uncle Henry was the salt of the ocean,” said David Kimo Frankel, the Native Hawaiian Legal Corp. attorney representing him on the case. “He was totally the salt of the earth, but really, he was the salt of the ocean.”

A Kamehameha Schools graduate, Chang Wo co-founded the Ewa Limu Project. He taught that limu was a crucial part of the web of life, a source of nutrition and healing. With help from the nonprofit Kua’aina Ulu Auamo, better known as KUA, he linked up with other practitioners in Limu Hui to share and pass on their knowledge.

“It’s the start of life, it has all the energy,” he said in a Limu Hui video. “It has all the vitamins. And without you realizing it, by eating limu, you don’t have to go to Longs Drugs and pick up all those pills. It’s right in our limu. And it’s something that we losing. We losing the knowledge of it. … We are the last ones that need to keep up this practice and get all the young kids involved.”

In 2009, he asked Wally Ito to join him at limu “show and tell” sessions, with Ito offering the scientific side of the equation while Chang Wo presented the traditional side. They talked to school groups, halau, Hawaiian clubs and neighbor island communities. At first, they were doing three or four talks a year, Ito said, but demand grew to the point where they were making one presentation almost every week.

“Uncle Henry said that where the fresh water meets the salt water, that’s where the ocean hanau, that’s where the ocean gives birth,” recalled Ito, Limu Hui coordinator for KUA. Many freshwater species spend part of their life cycle in the ocean, and saltwater species in their larval stage spend time in that brackish water environment, Ito noted.

Chang Wo urged residents on neighbor islands to cherish shoreline areas that were still relatively pristine, urging them to protect the entire sweep of land from mountaintop to ocean.

“He would warn them, this is what happened to Ewa, so watch out, look up mauka,” Ito said. “You need to be careful of what happens up mauka.”

Chang Wo was still working as a maintenance mechanic for the Department of Transportation’s Airports Division when he fell ill. He also worked for Hawaiian Electric and spent a decade at Johnston Atoll with Holmes & Narver Inc.

In recent years, “Uncle Henry” spent Saturdays with Ito and others at a state aquaculture facility at Sand Island, growing limu, including ogo, huluhuluwaena and eleele, along with mullet. They provided limu to community groups to plant in their areas. His friends vowed to carry on that mission.

A celebration of Chang Wo’s life will be held at Mililani Memorial Park and Mortuary, mauka chapel, in Waipahu, on Oct. 29, with visitation at 5:30 p.m. and the service at 6:30 p.m. Chang Wo had three sons, Mark and Timothy Chang Wo and Justin Alfafara, and eight grandchildren.

Kevin K.J. Chang, KUA’s executive director, said Chang Wo’s message continues to resonate.

“Henry’s story became a reminder to us all about how easy it is to lose something,” he said, “that in some cases nostalgia is not enough but a salve, that what we lose if we are not careful could actually be a link in the chain of life that we depend on.”