Status, Distribution, and Conservation of Native Freshwater Fishes of Western North America

Status of Native Hawaiian Stream Fishes, a Unique Amphidromous Biota

Robert T. Nishimoto and J.Michael Fitzsimons

doi: https://doi.org/10.47886/9781888569896.ch5

ABSTRACT Native Hawaiian stream fishes are represented by only five species belonging to two families, Gobiidae (‘o’opu nakea Awaous guamensis, ‘o’opu ‘alamo’o Lentipes concolor, ‘o’opu nopili Sicyopterus stimpsoni, and ‘o’opu naniha Stenogobius hawaiiensis) and Eleotridae (‘o’opu ‘akupa Eleotris sandwicensis). All species are found on each of the main Hawaiian Islands, and none is currently threatened or endangered. These animals are not true freshwater fishes, but rather share an amphidromous life cycle where adults live and reproduce in streams and larvae develop at sea. Techniques developed for sampling (electroshocking, seining) and assessment (e.g., index of biotic integrity, instream flow incremental methodology) in continental U.S. streams are inappropriate for Hawaiian streams. Thus, procedures were developed specifically for fishes in streams on oceanic islands of the tropical Pacific where amphidromy is the predominant life history mode. Geographical information systems-compatible data from ongoing statewide native stream fish surveys can soon be viewed on the Web site for the Hawai’i Division of Aquatic Resources (http://www.hawaii.gov/dlnr/dar). The 2000 Hawai’i Supreme Court decision on the Waiahole Water Dispute specifically provides for the maintenance of optimum flow for native stream fishes, and the Division of Aquatic Resources has adopted policies guiding instream water use decisions: (1) no net loss of habitat for native fishes, (2) use of a watershed or ahupua’a perspective, and (3) maintenance of an open corridor between the stream and the ocean to facilitate native species migrations. The preservation of indigenous Hawaiian stream fishes now has been elevated to the highest level of protection in the state.