It was rather hard to photograph this freshwater pond, also known as an anchialine pond, full of hyacinths, an invasive species. It was amazing.

Anchialine ponds are one of Hawaii's most threatened ecosystems. Anchialine pools are landlocked brackish ponds located close to the shoreline connected to the ocean via tunnels. Characterized by tidal fluctuations, these rare and fragile ponds are home to unusual plants and animals.

In the U.S., this habitat exists only in the Hawaiian Islands and, of the approximately 700 known anchialine pools, the majority are located on the island of Hawaii. Formed by volcanic activity, these pools are home to a unique assemblage of invertebrate and algal species, some of which are known to exist only in this habitat. In the last 20 years, non-native fish species have been introduced and/or invaded a majority of the pools. These alien species have gradually destroyed the ecological balance in many of the pools by eliminating many of unique endemic species.