Kawainui Marsh

State Wildlife Sanctuary

DLNR-DOFAW

Kawainui marsh encompasses a large area of Kailua that holds great history, and now is a State Wildlife Sanctuary. The land was once used by Native Hawaiians for fishing, taro farming, gathering of people, and religious and cultural practice. Now it is being conserved and restored to support Hawaiʻi's native and endangered waterbirds.

The Department of Land and Natural Resources (DLNR) Division of Forestry and Wildlife (DOFAW) manages all of Kawainui but focuses on restoring the Levee, Kahanaiki, Waiʻauia and the Restoration Ponds. DOFAW’s current management efforts work towards restoring the land to create suitable waterbird habitat for federally endangered waterbirds aeʻo (Hawaiian stilt, Himantophus mexicanus knudseni), ʻalae ʻula (Hawaiian gallinule, Gallinula chloropus sandvicensis), and ʻalae keʻokeʻo (Hawaiian coot, Fulica alai).

'Alae 'ula (Hawaiian gallinule) incubating eggs in nest. Photo by Lisa Roerk — ʻAlae ʻula (Hawaiian gallinule) incubating eggs in nest

Landscape and Hydrology

Kawainui marsh is located on the windward side of Oʻahu in the Kailua district. Kawainui Marsh State Wildlife Sanctuary is 830 acres, the largest remaining freshwater wetland in the state of Hawaiʻi and is a Ramsar Wetland of International Importance. DOFAW currently manages four restoration sites; Restoration Ponds, Kahanaiki, Levee, and Waiʻauia. All these management areas feature unique hydrology and wetland areas to provide suitable habitat for waterbirds.

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Levee

The Kawainui levee is a 6,300 foot earthen berm with a concrete wall that runs along Kawainui stream, on the north east side of Kawainui. The levee was constructed in 1966 by the Army Corps of Engineers to protect the Coconut Grove neighborhood of Kailua from flooding. The land extending mauka from the levee has been overtaken by invasive bulrushes and other vegetation that accumulate on peat (decomposed anaerobic plant matter that sits on the water’s surface). DOFAW is responsible for the vegetation control of the access road, wall, as well as the levee slopes and toe. Endangered waterbirds, especially ʻalae ʻula use the area between the toe and the adjacent Kawainui stream for foraging, loafing and breeding.

Restoration Ponds

The restoration ponds are the main focus for management at Kawainui. Previously, the restoration ponds were pasture land for cattle. In 2012 the Army Corps of Engineers created wetland habitat by excavating two ponds separated into 11 terraced cells (0.6 – 4.1 acres each) by low earthen berms. Maunawili stream intersects North (5 cells) and South ponds (6 cells). The cells are arranged in a mosaic pattern and rely on rainfall and flooding of Maunawili stream for water. During the wet season (October-April), ponds fill and provide foraging and nesting habitat for water birds.

Kahanaiki

Kahaniki is west of the restoration ponds and alongside Kahanaiki stream. A 0.5 acre plot of upland area is being restored in partnership with Le Jardin Academy. The plot expands over the hillside across from Kapaʻa quarry road and Le Jardin. The area was overrun with invasive vegetation, which has been removed and replaced with native plant outplantings.

History

Ko‘olau mountain range from Kawainui Restoration Ponds. Photo by Lisa Roerk. — Ko‘olau mountain range from Kawainui Restoration Ponds

Kawainui translates to “the great water”, it was named that because of the large body of water that covered the land when first settled by ancestral Hawaiians. The abundance of resources in the Kailua ahupua‘a, including the 450-acre fishpond of Kawainui and the surrounding lo‘i kalo (wetland taro farm), supported a large population of both ali‘i (royalty) and maka‘āinana (common people). Kawainui was known to have an abundance of awa (milkfish), ʻamaʻama (mullet), and ʻoʻopu (Hawaiian freshwater goby). Remains of upland terraces show that taro has been grown extensively and intensively in Kailua since the 13th or 14th century, possibly earlier.

Moʻolelo

Hauwahine

There are many fabled stories about Kawainui and its history of being a productive area for fishing and farming. One of the most famous stories tells about the protector of Kawainui, Hauwahine. Hauwahine is the water guardian of Kawainui fishpond, and she can take form as a beautiful woman sunning on the rocks or the guardian spirit of a Moʻo or lizard. She keeps Kawainui abundant with fish and brings health and wellness among the local families (Sterling & Summers 1978).

Mākālei Tree

Fables of the Mākālei tree tells about a mythological tree with powers to attract and fascinate fish. There is only one other tree with the same name, its female counterpart found in Hilo, Hawaiʻi. The root cutting of the female tree was said to be carried into Kailua and planted in the mud to bear a male Mākālei tree for the purpose of attracting fish, in which it was successful (Sterling & Summers 1978) .

Ulupō

Ulupō heiau is on the Kawainui side of Kailua road before entering Kailua on the Kalaniana‘ole Highway. Ulupō heiau is made up of many large pōhaku or stones stacked together and measures 140 by 180 feet with stone walls that can reach to 30 feet in height. The pōhaku, average 1.5 feet in width and construction of the heiau have been credited to the Menehune. It has been said that the heiau was built overnight by passing stones hand to hand over long distances. Some of the stones found at Ulupō are from Kualoa, ʻEwa, and even as far as Waiʻanae.

Ulupō is Oʻahu’s largest and oldest agricultural heiau where ceremonies are conducted to insure fertility of crops at Kawainui. Today, the non-profit organization Kauluakalana is working to restore the heiau, spring-fed loʻi kalo, and part of Kawainui for farming, cultural practice and to benefit endangered waterbirds.

Habitat Management Strategies

The main goal for Kawainui is to restore the area to make suitable foraging and nesting habitat for endangered waterbirds. All sites have different management issues, but the biggest threats over all management areas are invasive species (plants and mammalian predators) and water level control. Monitoring of the ʻalae keʻo keʻo, ʻalae ʻula, and aeʻo is accomplished by weekly nest surveys and population surveys.

Invasive Species Management

Kawainui's different management areas are threatened by different invasive species, and therefore require different approaches for vegetation control.

Restoration Ponds

The restoration ponds are overrun with California grass (Brachiaria mutica) and honohono grass (Commelina diffusa). Mechanical and chemical control was found to work best for controlling invasive grasses in the management ponds. DOFAW uses a variety of heavy equipment including an amphibious machine called a Marsh Master to manage invasive plants.

Levee

At the levee, areas of the marsh are almost completely covered by non-native bulrush (Schoenoplectus californicus). Currently DOFAW is in the planning process of removing bulrush near the levee using a the Marsh Master.

California bulrush (Schoenoplectus californicus) encroaching Kawainui stream

Kahaniki

Kahaniki was overrun with various upland invasive species. In partnership with Le Jardin Academy, DOFAW staff and volunteers were able to clear out a hillside area for native outplanting restoration. Grades K-12 at Le Jardin are currently filling the cleared area with different native and culturally important plans.

Birds of Kawainui

ʻAlae keʻokeʻo or Hawaiian Coot (Fulica alai)

ʻAlae keʻokeʻo is an endangered waterbird the Rallidae family that is endemic to Hawaiʻi. ʻAlae keʻokeʻo can be found at Kawainui year round. ʻAlae keʻokeʻo is very similar in appearance to the American coot (Fulica americana), but they are two distinct species. In 1970 ʻalae keʻokeʻo was federally listed as an endangered species. ʻAlae keʻokeʻo are found on all major Hawaiian islands except for Kahoʻolawe, however 80% of the population occurs on Oʻahu, Maui, and Kauaʻi. Based on DOFAW’s statewide biannual waterbird survey, there is an estimated population of 2000-4000 ʻalae keʻokeʻo in the state (Pratt & Brisbin 2002) .

ʻAlae keʻokeʻo are dark gray chicken-shaped waterbirds that are about 15 inches in height. They have white bills with a bulbous frontal shield and 1-3% of the population has a red shield on their white beaks. ʻAlae keʻokeʻo have blue-gray lobed feet to help them swim. Males and females can only be distinguished by size and vocalizations. They vocalize using short sharp keeks and croaks. Downy chicks have red pigmented skin and beaks with a yellow tip, and have fuzzy black down with a bald head.

ʻAlae keʻokeʻo are non-migratory birds but there have been cases of irregular movement between islands based on rainfall. ʻAlae keʻokeʻo tend to occur in low elevation wetlands and forage in deeper waters (12-48 inches deep) and live in fresh to brackish water. Their main foraging technique is dabbling on the surface of the water and diving, open water is their preferred foraging habitat. Much of their diet is unknown but they do feed on seeds, leaves, stems of aquatic plants, and small invertebrates.

Breeding season is year round but depends on rainfall. In Hawaiʻi the small Indian mongoose (Herpestus auropunctatus) is one of the biggest threats to their chicks and eggs. ʻAlae keʻokeʻo chicks have a low survival rate, so many clutches are produced in a lifetime but not many chicks survive to fledglings. ʻAlae keʻokeʻo are threatened due to predation, invasive vegetation, disease, and habitat loss. DOFAW works industriously to create suitable habitat, remove and exclude predators, and monitor the ʻalae keʻokeʻo population.

Koloa Maoli or Hawaiian duck (Anas wyvilliana)

Koloa

The koloa is an endemic species of waterfowl in Hawaiʻi. Historically, koloa used to inhabit all major Hawaiian islands except for the dry islands of Kahoʻolawe and Lānaʻi. By the 1920s ornithologists began to notice their decline. Today, populations of pure koloa only remain on Kauaʻi and higher elevation areas of Hawaiʻi island. They are threatened by habitat loss and hybridization with feral mallards (Anas platyrhynchos) (Engilis et al. 2002 ).

Koloa x Mallard Hybrid

Kawainui used to support a healthy Koloa population. Many koloa-mallard hybrids can be found loafing and foraging at Kawainui. Large flocks of hybrids can be found all the time during the wet season. Koloa are very similar in appearance to mallards but are much smaller and both males and females are brown. Mallards and hybrids can be characterized by their curled tail feathers and green or partially green heads on males.