References

Links to published information used in writing the preceding pages are listed here. For each source listed, a key exerpt is also given.

About the Nawiliwili Bay Watershed

‘Āinakumuwai: Ahupua‘a of Nāwiliwili Bay: http://lauhala.com/ainakumuwai/index.htm

“It’s time to think about our home.”

This excellent educational web site has been our primer, our first source of knowledge about the place of Nawiliwili Bay and Hulē‘ia River, about ainakumuwai and the Island of Kaua‘i, about our home.

            “Hulē‘ia Stream is by far the biggest source of freshwater input into Nawiliwili Bay. This stream is culturally significant for being the location of ‘Alekoko Fishpond as well as many other fishponds (now gone). Additionally, Hulē‘ia Stream once was the water source for the staplefood (taro) of the Hawaiian population. There is saltwater influence in this stream for over 2 miles upstream. The lower part of Hulē‘ia is important as an estuarine environment and nursery ground for many marine fish and crustacean species. It is also important as a water bird habitat because many of our endangered water birds can be found in this portion of the stream. Unfortunately, 50 or so years ago the red mangrove was accidentally introduced and is thriving and is prolific along the banks as far up as the saltwater influence is present. The mangrove may contribute a significant amount of organic material to the stream, increasing turbidity and nutrient concentrations (KRP Information Services, 1993). Additionally, the massive amount of roots extending from this plant into the stream may slow flows and trap sediment.” (p.19)

Assessment And Protection Plan For The Nawiliwili Watershed: Phase 2–Assessment Of Contaminant Levels, Oct. 2003: http://scholarspace.manoa.hawaii.edu/handle/10125/22254

“The increase in plant productivity introduces organic material, which eventually dies and decays.  The decaying organic matter depletes the oxygen supply required by aquatic organisms and generates bad odors.  Recreational activities, such as swimming and boating, are negatively affected by excess plant growth.  Depleted oxygen levels reduce the quality of the fish habitat and can encourage the propagation of fish that are adapted to other environments, such as those with less oxygen, and thereby disturb the natural balance in the delicate environment.” (p.5)

Assessment and Protection Plan for the Nawiliwili Watershed: Phase 3 – Restoration and Protection Plan, Dec. 2004: http://health.hawaii.gov/cwb/files/2013/05/PRC_WatershedNawiliwiliBay.pdf

        “Invasive plant and animal species pose a threat to not only all of Hawai‘i’s watersheds and water resources, but also the tourism-based economy, agriculture, health, and quality of life. Habitat destruction and the introduction of alien species have been the predominant cause of biodiversity loss in Hawai‘i for over a century. More native species have been eliminated from Hawai‘i than anywhere else in the United States (KISC, 2003). Native species comprise only a small portion of the species composition in the Nawiliwili Watershed. This area is named Nawiliwili because at one time native wiliwili trees were abundant. Now, less than a handful of these trees have been identified in the watershed. Non-native and invasive vines trees, shrubs and grasses are instead the dominant populations. On a tour led by one of the local kayak companies on the Hulē‘ia River, a single plant (moa) and a single wiliwili tree were pointed out as the only native species in the area.

…

       The red mangrove Rhizophora mangle is an invasive species that is actively spreading in the Nawiliwili Watershed. Hulē‘ia estuary and ‘Alekoko Fishpond have been inundated with mangrove. The rock walls of the fishpond are being torn apart by the mangrove roots, and the estuary itself seems to be shrinking in size as the mangrove closes in. According to some local residents, the wall of the fishpond was still clearly visible in the 1980s, but now it is completely obscured by the mangrove. It is uncertain whether the mangrove is providing any water quality or aquatic habitat benefits. … In Hawai‘i, the mangrove may slow flows and trap sediment, thereby increasing its own propagation success and in the process choke ‘Alekoko Fishpond. Although mangroves may provide many water quality benefits in their native environment, in Hawaii they tend to encroach upon habitat used by native water birds and migratory shorebirds. Upstream in the Hulē‘ia estuary, hau dominates where the tidal influence wanes and there is more usable habitat for native water birds as the mangrove becomes less abundant. Therefore, controlling the spread of mangroves and removing some of their existing range are necessary for the protection of native species (David Smith, personal communication, 2003).” (p. 25-26)

Hawai‘i Watershed Guidance, Aug. 2010: http://hawaii.gov/dbedt/czm/initiative/nonpoint/HI%20Watershed%20Guidance%20Final.pdf

“Traditional Hawaiian management adopted a holistic approach that recognized the interconnectedness of land and sea, the interactions among species, the rhythms of the seasons, and the impacts of overuse on resources. Today, our use of the land and water has impaired water quality and beneficial uses of streams and coastal waters. Hawai‘i’s watersheds support a diversity of biota and provide a range of services, including water, food, and recreation. More effective watershed management is needed to restore, protect, and maintain the structure, function, and services of Hawai‘i’s marine and terrestrial ecosystems.” (p.5)

U.S. Fish & Wildlife Service Hulē‘ia National Wildlife Refuge: http://www.fws.gov/huleia/index.html

“Management

In accordance with the mission of the U.S. Fish and Wildlife Service, one of the most important management functions at Hulē‘ia NWR is to provide habitat that meets the life history requirement needs of the five endangered water birds, with an emphasis on the kaola maoli. We accomplish this goal by:

• • • optimizing water levels for maximum habitat size and value for endangered, resident, and migrating water birds while reducing the negative effects of invasive species
    • constructing impoundments with small islands for nesting and roosting, controlling water level, disking, tilling, and spraying herbicide when necessary
    • conducting predator control
    • expanding understanding, appreciation, and stewardship of the wetland and coastal ecosystems through wildlife-oriented educational opportunities; and
    • developing cross-programmatic and community partnerships to enhance wetland and watershed habitats.

An ongoing challenge for the next 7-10 years will be to create and restore 60 acres of open, productive wetlands for waterbird production and maintenance for the five endangered waterbirds.”

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About Red Mangrove Infestation and Eradication Efforts in Hawaii

Mangroves as alien species: the case of Hawaii: https://www.fs.fed.us/psw/publications/allen/psw_1998_allen001.pdf

“Prior to the early 1900s, there were no mangroves in the Hawaiian Archipelago. In 1902, Rhizophora mangle was introduced on the island of Molokai, primarily for the purpose of stabilizing coastal mud flats. This species is now well established in Hawaii, and is found on nearly all of the major islands. … Mangroves are highly regarded in most parts of the tropics for the ecosystem services they provide, but in Hawaii they also have important negative ecological and economic impacts. Known negative impacts include reduction in habitat quality for endangered water bird such as the Hawaiian stilt (Himantopus mexicanus knudseni), colonization of habitats to the detriment of native species (e.g. in anchialine pools), overgrowing native Hawaiian archaeological sites, and causing drainage and aesthetic problems. Positive impacts appear to be fewer, but include uses of local importance, such as harvesting B. gymnorrhiza flowers for lei-making, as well as some ecological services attributed to mangroves elsewhere, such as sediment retention and organic matter export.”

All About Mangrove – Mangrove Removal Efforts: He’eia, Hawaii: http://mangrove.wordpress.com/

“He’eia fishpond is the second largest remaining fishpond of its kind on the windward side of the island of O’ahu in Hawaii. It is owned by Kamehameha Schools and managed by an organization called Pae Pae O He’eia. Mangrove has become a problem in the pond, filling the pond in with anoxic and smothering sediment. Pae Pae O He’eia uses chainsaws and loppers to eradicate the mangrove as much as possible, and is making slow and steady progress with the help of dedicated and hardworking staff and volunteers. Mangrove is just one example of the damage invasive species can do when introduced to foreign lands.”

Malama O Puna – Wai Opai Mangrove Project: http://www.malamaopuna.org/waiopae.php

“Our pilot project site of Wai ‘Opae had 20 acres of mangrove infestation, which is now nearly eradicated, and we are replanting with natives: primarily hala, naupaka and kou. There is milo sprouting up naturally all over the site. There are an additional 15 acres of mangroves at 4 sites on the island. We are applying the methodologies we developed at Wai ‘Opae the additional sites: Poho‘iki and Paki Bay in Puna, Onekahakaha in Hilo. One other site, Alula Bay in Kona, the mangroves are threatening a heiau, so we plan to use volunteers to cut and remove them, and are working in collaboration with Keala Ching and Na Wai Iwi Ola Foundation (the cultural practioners who use the heiau) and Kaloko-Honokohau National Historical Park. There are 2 additional sites on the island where property owners are already engaged in eradication efforts.”

Removal of alien red mangrove from Kaloko-HonokohauNational Historical Park, Dec. 2008: http://manoa.hawaii.edu/hpicesu/techr/162/v162.pdf

“In the late 1970s red mangrove, Rhizophora mangle, an invasive alien climax tree, invaded the Kaloko-HonokohauNationalHistoricalPark saltwater marshes and formed dense closed forest stands. The mangrove impaired nationally significant archeological sites, not only visually but also the physical structures necessitating its removal. The need to protect the physical integrity of the structures complicated any work to control the trees. Beginning in 1988 park maintenance crews carefully began hand-removing the mangrove and systematically controlling reinvading seedling sprouts. By the mid-1990s all mangrove stands on park-owned lands had been removed. Controlling reinvading mangrove sprouts remains a never-ending maintenance endeavor.”

Red mangrove eradication and pickleweed control in a Hawaiian wetland, waterbird responses, and lessons learned, M J. Rauzon and D. C. Drigot: http://www.issg.org/database/species/reference_files/TURTID/Rauzon.pdf

“Alien red mangrove (Rhizophora mangle) and pickleweed (Batis maritima) are major invasive plants in Hawaiian wetlands, including Nu’upia Ponds, a 195 hectare wildlife management area and historic Hawaiian fishpond complex on U.S Marine Corps Base Hawaii. These fishponds are also home to approximately 10% of Hawai’i’s en­demic and endangered black-necked stilt (Himantopus mexicanus knudseni) population and at least 16 species of native fish. Invasive plants were changing the ecology and character of the fishponds from Hawaiian to Floridian. After 20 years of effort with thousands of volunteer hours, and over USD 2.5 million of contracted labour, over 20 acres of mangrove were removed. Mangroves were cleared by hand, shovels, and chain saws in archaeologically-sensitive areas and grappled with heavy tracked equipment in less-sensitive areas. Work was performed in the non-nesting season of the resident waterbirds. Prior to cutting, mature mangrove stands had been colonised by black-crowned night-herons and cattle egrets, causing work schedule alterations and the need for hazing permits. Pickleweed, an invasive ground cover, is annually plowed using Amphibious Assault Vehicles during “mud ops” training manoeuvres. The results show that stilts readily colonise mudflats cleared of alien vegetation, especially near established breeding areas. Lessons learned regarding waterbird conservation are discussed.”

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About Plants

Native Plants Hawaii: http://nativeplants.hawaii.edu/index/

“Learning about native Hawaiian plants and their uses have the capacity to connect us to Hawaiʻi’s cultural past. The echoes of the past can resonate today as we understand, appreciate and grow native Hawaiian plants”

Canoe Plants of Ancient Hawaii: http://www.canoeplants.com/

“These Polynesian voyagers of a great oceanic nation trusted in a benevolent order that included an active relationship with plants. A few life-sustaining plants had long been cultivated through selection and preservation. Upon the sailing canoes were stashed precious cargo of the shoots, roots, cuttings and seeds of these plants for food, cordage, medicine, fabric, containers, all of life’s vital needs. This was a culture without clay or iron whose people knew the intrinsic value of the cargo they carried beyond the horizon.”

Hawaiian Plants and Tropical Flowers: http://wildlifeofhawaii.com/flowers/

“The Hawaiian Islands have an interesting variety of plant species, with about half being native species and half being introduced species. Because of Hawaii’s remote, isolated location in the middle of the Pacific Ocean, 89 percent of the native plants found here are endemic (native to nowhere else in the World). Because Hawaii is such a tropical paradise for plants, many of the non-native plants brought here have gone wild, and a number of them have become seriously invasive. A few introduced plant species were brought here by the ancient Polynesians in their canoes, while the rest, including many food plants, forage crops, forestry trees, exotic tropical flowers, former houseplants, and accidental weeds were brought here more recently from many different places around the World.”

The Plant List: http://www.theplantlist.org/

“The Plant List provides the Accepted Latin name for most species, with links to all Synonyms by which that species has been known. It also includes Unresolved names for which the contributing data sources did not contain sufficient evidence to decide whether they were Accepted or Synonyms.”

Plants Database, USDA Natural Resources Conservation Service: http://plants.usda.gov/java/

“The PLANTS Database provides standardized information about the vascular plants, mosses, liverworts, hornworts, and lichens of the U.S. and its territories. It includes names, plant symbols, checklists, distributional data, species abstracts, characteristics, images, crop information, automated tools, onward Web links, and references. This information primarily promotes land conservation in the United States and its territories, but academic, educational, and general use is encouraged. PLANTS reduces government spending by minimizing duplication and making information exchange possible across agencies and disciplines.”

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Other Related Articles

Chemical Ecology of Red Mangroves, Rhizophora mangle, in the Hawaiian Islands, Jul. 2010:http://www.bioone.org/doi/abs/10.2984/65.2.219?journalCode=pasc

“The coastal red mangrove, Rhizophora mangle L., was introduced to the Hawaiian Islands from Florida 100 yr ago and has spread to cover many shallow intertidal shorelines that once were unvegetated mudflats. We used a field survey approach to test whether mangroves at the land-ocean interface could indicate watershed inputs, especially whether measurements of leaf chemistry could identify coasts with high nutrient inputs and high mangrove productivities.”

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