Hart Crowser Hawai‘i Office He‘eia Work Day

He‘eia Stream Estuary

The Hart Crowser Hawai‘i team working at He‘eia Stream Estuary. In the area in the right half of this photo we’ve removed the invasive knot grass. The remaining akulikuli is looking a bit trampled, but will recover quickly and thrive.

On Wednesday, June 27, the Honolulu staff each dedicated a vacation day to volunteer with Hui Ko‘olaupoko (HOK) at He‘eia, O‘ahu. HOK is a non-profit watershed management group established in 2007 to work with communities to improve water quality through ecosystem restoration and storm water management, focusing specifically in the Ko‘olaupoko region on windward O‘ahu. HOK’s mission is to protect ocean health by restoring the ‘āina: mauka to makai (land: mountain to sea).

HOK implements innovative projects that effectively manage and protect water quality and natural resources. Projects have included storm water low-impact development projects such as rain gardens, and other watershed focused projects.

The He‘eia estuary restoration project is a collaboration with several other non-profits to restore the ecosystem of He‘eia Stream. This project is aimed at improving water quality and increasing habitat for native aquatic animal species by removing invasive plants and replanting native Hawaiian species. In the past 3 years, about 4 acres of mangrove have been cleared and native species planted. Our work for the day consisted of removing invasive “knot grass” from the estuary flats where it was overwhelming the native vegetation that was planted following removal of the mangrove.

For the plant nerds among us, the predominant native vegetation we protected in the estuary flats were:

  • Akulikuli (Sesuvium portulacastrum), an indigenous coastal succulent ground cover that has been very successful in the estuary
  • Mau‘u‘aki‘aki (Fimbristylis cymosa), a sedge that forms short, rounded tufts of light green narrow, stiff, erect blades
  • Ahuawa (Mariscus javanicus), a greenish blue rush with beautiful brown spiky umbrella flowers/seed pods

We also got to see many native and rare species that have been planted along the stream bank, including Ilima with its tiny flowers that need about 500 to make a lei!); Lama; Ohai; and Mao hau hele. All of these plants have interesting cultural uses and significance, well explained at these website links by our friends at Hui Kū Maoli Ola, an amazing native plant nursery in upper He‘eia.

One of the delights of working on this project was getting to visit the adjacent He‘eia Fishpond. Paepae o Heeia, another non-profit, has been restoring the 88-acre, 800-year-old fishpond since 2001. He’eia Fishpond was likely constructed by hundreds, if not thousands, of Hawaiians who passed and stacked rocks and coral for approximately 2-3 years to complete the 1.3-mile wall. Fishponds helped Hawaiians practice sustainable aquaculture long before western contact. There are only a few fishponds remaining of the approximately 100 that are known to have existed on O‘ahu, as most have been destroyed by development. Restoration of remaining fishponds has been a big part of the Hawaiian cultural renaissance over the past 25 years. While we didn’t work on the fishpond itself, we were able to cross the stream to walk on the fishpond walls (which are dry stacked!), to view the functioning sluice gates, and to learn more about fishponds.

We had a fun team-building day that successfully cleared invasive species from a large area, and learned a bit more about native plants and Hawaiian culture around fishponds. Thanks to HOK for hosting us, and kudos to our Hawai‘i team for being adventurous and volunteering their own time to take on this project!

Ko‘olau mountains

The beautiful Ko‘olau mountains in the distant background, a portion of the fishpond wall and sluice hale in the midground, and our team working hard in the foreground.

Walking on Fishpond Wall

Walking on the fishpond wall after a long day of work; the enclosed fishpond is to the left, with the open waters of Kāne‘ohe Bay to the right.

Hawaii team

Our Hawaii team is all smiles visiting He‘eia Fishpond after a long day of work helping to restore He‘eia Estuary.

Sluice gates

The working mākāhā (sluice gates) of He‘eia Fishpond.

Ilima,official flower of O‘ahu

The beautiful native Ilima, the official flower of O‘ahu. The little flowers are treasured for lei – it takes more than 500 of these flowers to make a delicate and special lei.