The isolation of the Hawaiian archipelago coupled with the way ocean currents circulate and the unique water temperature has resulted in Hawai'i having some of the most unique plants and animal species worldwide. Hawai'i is the endemic species capital of the world. In general it was very hard for species to colonize the archipelago. Those that arrived tended to have long larval stages and were transported here through a number of mechanisms. Some were transported here through ocean currents, and in modern times some were introduced for aquaculture or for sport fishing.