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Native Hawaiian Streams & Bioassessment . Importance of streams to the Hawaiians Native stream creatures Bioassessment of Hawaiian Stream. Ancient Hawaiians placed a supreme value on water itself. The Hawaiian word for water is wai , Waiwai is the word for wealth or value.
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Native Hawaiian Streams & Bioassessment • Importance of streams to the Hawaiians • Native stream creatures • Bioassessment of Hawaiian Stream
Ancient Hawaiians placed a supreme value on water itself. The Hawaiian word for water is wai, Waiwai is the word for wealth or value. Kumuwai means both the source of wealth as well as the source of a stream. The translation of our concept of the watershed into Hawaiian is aina kumu wai or the land that is the source of the water. Without clean and ample free flowing streams native plants and animals could not have survived. Without these plants and animals, native Hawaiians could not prosper and be wealthy. Waikaumalo Stream, Hawai'i The Importance of Water
5 native species of fishes (four endemic, one indigenous, i.e., native but found elsewhere too) 2 species of crustacean (all endemic) 3 species of mollusk (all endemic). Animals Native to Hawaii
‘O'opu alamo'o 'O'opu nopili 'O'opu nakea 'O'opu naniha 'O'opu akupa Hawaii's Native Stream Animals
‘Opae kuahiwi Opae 'oeha'a Hawaii's Native Stream Animals
Hihiwai Hapawai Pipiwai Hawaii's Native Stream Animals
The Hawaiian Archipelago, situated in the middle of the Pacific Ocean. It is the most isolated landmass in the world. The west coast of the U.S. is 2,400 miles away and Japan is 3,800 miles away Hawaiian freshwater animals evolved from marine forms. Isolation has resulted ina sparse freshwater fish population Geographic Isolation
They are small compared to larger streams in the US mainland. Numerous waterfalls. This feature gives the stream a steep profile. Stream flow tracks rainfall pattern. Freshets: short-duration, high-volume flows due to heavy rainfall Life in Hawaiian streams have adapted to life in these highly energetic, sometimes violent, and ever changing environment . Wailua Valley, Kaua'i Characteristics of Hawaiian Streams
Flash floods flush away rotting organic debris. They remove fine sediments that can smother the eggs of stream animals. They open up the stream where it flows into the sea Flood waters entering the sea provide a biological signal. Importance of Freshets
Adaptations to Hawaiian Streams • Adaptations: structures or features unique to a species, or a group of species, which allow them to survive and reproduce in a specific habitat . • Random mutation in the genetic code (DNA) of an animal. • Natural selection through the environment of a species.
Hawaiian freshwater animals evolved from marine forms. These animals still maintain a strong dependence upon the sea. Amphidromy: the adults live and breed in fresh water streams, while the newly hatched larvae swim out to sea and remain there for several months before returning to freshwater. Hakalau Stream, Hawai'i The Mauka (mountain) to Makai (sea) Connection
Amphidromous Life Cycle • What might be an advantage to this type of life cycle? • The larvae in the ocean provide a reservoir for each species to repopulate streams after catastrophic events such as hurricanes, flashfloods, and lava flows • In addition, larvae are also moved by ocean currents to other streams and even islands, which ensures dispersal and maintains a complete gene pool.
Some species of fish have adapted their pelvic sucking disk to climb waterfalls. The pelvic sucking disk also helps in maintaining position. The ‘o‘opu nopili’s mouth has evolved to also act like a suction cup which aids in climbing Climbing Waterfalls
Threats to Native Species • Hawaii's stream environments are poorly surveyed • Huge die-offs of native ‘o‘opu chronically occur in de-watered streams which are preceded by rampant disease in the population. • What factors contribute to these die-offs?
Development has diverted water from streams for potable water, agriculture and hydropower. Diverted water… Creates physical barriers between streams and the open ocean. Reduce available habitat and distorts the natural rhythm of water movement Reduce flow which erodes the food base which supports native stream species in favor of less-preferred slow-water tolerant forms and other invasive species . Diversion of Water
Today more than 50 species of alien fishes, invertebrates, reptiles, amphibians and plants are established in our streams and reservoirs Many of these species were intentionally released Others were simply dumped in our streams with no thought given to possible consequences. Alien and Invasive Species
Invasive species increase predation and competition on native species with few natural defenses. It is suggested that invasive species are transmitting parasites to native stream fishes. How do we assess the health of our streams? Invasive Species
Maintain the mauka-makai lifeline to ensure healthy populations of stream flora and fauna Riparian (streamside) vegetation is needed Prevent the release of additional alien species into the stream Keep the streams clean Minimize pollution What can you do?
