Hawaiian Stream Diversions Alter Aquatic Ecology

For more than 100 years, Hawaiian streams have been diverted to irrigate agricultural plantations. But, until now, the potential costs in terms of Hawaii’s endemic stream life were undocumented. A recent study reports drastic changes in stream communities below the diversion of a Maui stream. Below the diversion of Iao Stream, Maui; three macroinvertebrate groups (which include insects, crustaceans, and snails) disappear. Densities of other macroinvertebrate groups drop by 46 percent below the diversion. The changes in the macroinvertebrate community could have serious impacts on endemic fish that rely on them for food.