What is an anchialine pool?

Figure 2-19 Anchialine pools, such as the Kuki‘o Pools on Hawai‘i Island, are unique environments found only in the coastal tropics and sub-tropics. The pools have no surface connection to the ocean yet can range from fresh to brackish, due to an underground connection to the ocean. Anchialine pools are critical habitat for several rare and endemic species, such as opae‘ula red shrimp, snails, and insects. (©2010 Rosa Sey, “One of the Kuki‘o anchialine ponds,” used under a Creative Commons Attribution-NonCommercial-NoDerivs license.)