Long thorn kiawe (Prosopis juliflora or LTK), is designated a noxious weed. LTK has thorns which can grow up to three inches in length. Removal of the LTK from the island remains as a significant challenge for the project. Seeds produced by LTK are disbursed by ocean currents and propagate along Hawaii’s shoreline. The Oahu Invasive Species Committee (OISC) assessed Mokauea's Island's LTK growth on April 14, 2007 and LTK removal operations commenced on June 16, 2007 with the help of over 140 volunteers from the community as well as State, Federal, and City and County of Honolulu governments.
On July 12, 2007, employees from the Department of Agriculture and the Department of Land and Natural Resources, - Division of Forestry and Wildlife notched and applied herbicide to over 90 LTK trees. This notching technique is very effective at killing the LTK trees.
On September 8, 2007, the OISC and volunteers removed 86 LTK plants. Kai Makana will continue LTK removal operations and replant former LTK growth areas with native Hawaiian plants that are being grown in a stock area on the island.