Pacific Network — Featured Resource Mixohaline Waters

Description: Often referred to as 'brack- NHP (KAHO) in conjunction with adjacent Management: The extreme range of con- ish', mixohaline describes the delicate balance land use changes. As PACN Vital Signs pro- ditions found in these mixohaline habitats of water that is neither fresh nor marine. So tocols are completed, water quality, fish, and supports very specialized and rare biota neces- why should we be concerned about mixed-up invertebrates will be monitored in many of the sitating management protection. The wetland waters? Coastal wetlands, , anchialine identified mixohaline waters. in AMME has two endangered species of birds, pools, and some groundwaters are examples of the nightingale reed-warbler (Acrocephalus these biologically and anthropologically vital Data: The three main databases compiled by luscinia) and the Mariana common moorhen resources. These water bodies provide unique NPS for the PACN (NatureBib, NPSpecies, and (Gallinula chloropus guami); as as a spe- habitat for organisms that include fish, water- Dataset Catalog) provide the most comprehen- cies of concern, the humped tree snail (Partula fowl, rare shrimp, and plants. sive resource for the many types of mixohaline gibba). The top 4 m of Lake Kauhakö is brack- water bodies found therein. Additionally, ish and supports an array of algae and inverte- On many oceanic , fresh water (supplied the Natural Heritage Program of the Nature brates. Anchialine pools and fishponds contain by rainfall) can be found underground floating Conservancy of Hawaii published a biological fish, endemic shrimp, snails, calcareous algae, on a layer of called the “transi- database of rare species and natural communi- sea grass, and provide specialized habitat for tion zone.” These layers of fresh and brackish ties in anchialine pools in Hawaii in 1987. endangered birds, native plants, amphibians, water flow down to the margins of the islands and the endemic Hawaiian damselfly Megala( - and mix with seawater filtering through the Status & Trends: Many mixohaline re- grion xanthomelas). Long-term monitoring of rocks below. Groundwater flow influences the sources are impacted by people (e.g. develop- mixohaline water bodies and their biota should condition of biotic habitats and communities ments). For example, human encroachment has provide resource managers with the necessary primarily by supplying fresh water and nutri- negatively affected hydrology near the AMME information to sustain their critical existence. ents to plants and animals. wetland, threatening its unique flora and fauna. Human uses of the resources in and around Cultural Significance: Historically, mixo- Pearl Harbor have contributed to contamina- haline water bodies, although undrinkable, tion of the groundwater. Anchialine pools and provided people with water for agriculture, fishponds range from pristine to heavily im- Where to see mixohaline aquaculture, bathing, food harvesting and pacted. Even reconstruction of the wall enclos- waters: processing materials. This resulted in human ing Kaloko fishpond is contributing to changes Anchialine pools and fishponds are common in settlements gathered around these important in its water quality. Only the remote anchialine West Hawai'i National Parks. In addition, Lake water resources. Subsequently, coastal strand pools of Hawaiÿi Volcanoes NP, and KALA's Kauhakö in KALA and the wetlands of AMME are communities contribute to the accretion of Lake Kauhakö are currently undisturbed. other important examples of mixohaline resources. used by turtles and seals which were also sources of food. In Hawaii, resources from mixohaline habitats were often traded for resources from the forests or .

Inventories: Related inventories in Pacific From left to right: Lake Island Network (PACN) parks include vegeta- Kauhakö tion of the American Memorial Park (AMME) at KALA; wetland, aquatic fauna of Kauhakö Lake in Wetlands at AMME; and an Kalaupapa NHP (KALA), and both flora and anchialine pool fauna of the fishponds and anchialine pools at KAHO. along the Ala Kahakai National Historic Trail (ALKA), which includes the National Parks on the island of Hawaiÿi. Accurate identification and mapping of the wetlands and anchialine pools is a vital component of these inventories. NPS photos Monitoring: Anchialine pool biota and water quality are presently monitored along ALKA, particularly at Kaloko-Honoköhau

Pacific Island Network News 2006 Featured Resource http://science.nature.nps.gov/im/units/pacn/