Lehua Island is a small, crescent-shaped island in the Hawaiian islands, 0.7 miles (1.1 km) north of Niʻihau, due west of Kauai. The uninhabited, 279-acre (1.13 km2) barren island is a tuff cone which is part of the extinct Niʻihau volcano.
Lehua was one of the first five islands sighted by Captain James Cook in 1778 which he spelled as "Oreehoua".
Lehua Island is a Hawaii State Wildlife Sanctuary. As a restricted sanctuary, all activities are prohibited on the island without a permit. Public access to the island is restricted to areas below the high tide water mark. Lehua provides habitat for at least 16 species of seabirds, as well as non-native Pacific rats. A population of European rabbits had lived on the island for many years but were removed in 2005.
When weather and wave conditions permit crossings from Kauai, Lehua is a noted destination for snorkeling and scuba diving. It is also well known for an unusual geological formation dubbed "the keyhole". Located in one of the crescent's narrow arms, this is a tall, thin notch cut from one side, all the way through to the other side of the arm.
Conservation and RestorationEdit
Lehua is one of the largest and most diverse seabird colonies in the main Hawaiian Islands with 17 seabird species and 25 native plants (14 Hawai`i endemics – occurring nowhere else in the world) inhabiting the steep, rocky, windswept slopes of the tiny island. Lehua is an important part of native Hawaiian culture—the Ni‘ihau community gathers ‘opihi (limpets) in adjacent marine waters and on the island are several important native Hawaiian cultural sites.
Invasive rats were foraging on native plants and seeds, which imperiled the entire ecosystem. These impacts contributed to erosion which can in turn impair near-shore marine and coral ecosystems and fisheries. Native birds like the threatened Newell's Shearwater were likely being restricted from breeding on Lehua Island due to predation by rats. Smaller, open-nesting seabirds such as terns and noddies were conspicuously absent from Lehua (save small numbers found in sea caves), also a suspected artifact of rat predation. Invasive rats ravage other threatened birds.
Therefore, in August 2017, the DLNR Division of Forestry and Wildlife (DOFAW) with project implementation partner Island Conservation implemented an aerial application of bait with supplemental hand application to eradicate non-native invasive rats. Signs of seabird revival were found post-eradication.  The official Final Monitoring Report Issued on Lehua Restoration Project found no rodenticide in environmental samples and minimal impact to species other than rats.
- "Hawaii Wildlife Sanctuary Rules" (PDF). Hawaii Administrative Rules section 13-126. Hawaii Department of Land and Natural Resources. Retrieved 3 December 2015.
- "Final Environmental Assessment - Lehua Island Restoration" (PDF). Final Environmental Assessment - Lehua Island Restoration. Hawaii Office of Environmental Quality Control. Retrieved 3 December 2015.
- "Operation Lehua Begins". DNLR. August 23, 2017. Retrieved May 1, 2020.
- "Promising Signs of Seabird Revival on Lehua". Island Conservation. November 27, 2017. Retrieved May 1, 2020.
- "Final Monitoring Report Issued on Lehua Restoration Project". DNLR. August 20, 2018. Retrieved May 1, 2020.
- Hawaii Department of Land and Natural Resources. (12 January 2010). Rules Regulating Wildlife Sanctuaries (PDF). In, Hawaii Administrative Rules, § 13-126.
- Hawaiian Volcano Observatory. (29 September 1995). "Oʻahu, Niʻihau, and Kauaʻi". Volcano Watch.
- Light List, Volumes 1-7. United States Coast Guard. 2005.
- Lehua Island Ecosystem Restoration Project
- Final Environmental Assessment - Lehua Island Restoration (8 October 2005)