Papahanaumokuakea and Laysan Island

Laysan Island (Kauo) was formed approximately 17 million years ago, and has a land mass of 1,015 acres, making it the second largest in Papahanaumokuakea. It is oval in shape, about 1 mile wide and 1.5 miles long, with an elevation of about 40 feet, and a hypersaline lake in the middle of the island.

The island’s ecosystem was severely altered by human exploitation in the late 1800s. It was extensively mined for bird guano, used as a fertilizer. Later, feather collectors killed birds by the hundreds of thousands. In the early1900s rabbits were introduced and ate the island’s plants causing the extinction of three species of birds – the Laysan Rail, the Laysan Honeycreeper, and the Laysan Millerbird. These events caused a public outcry which led to the creation of the Hawaiian Islands Bird Reservation by President Theodore Roosevelt in 1909.

Laysan Island is surrounded by a shallow-water coral reef ecosystem that is rich with numerous invertebrate species, algae, juvenile fishes, Green Sea Turtles and Hawaiian Monk Seals (Monachus schauinslandi). Twenty-seven species of stony corals are recorded including encrusting corals, branching corals, and some rare species. Some common invertebrates include rock-boring sea urchins and encrusting coralline algae. Of the 75 native invertebrate species found on Laysan Island, 15 are endemic.

Laysan has the fullest complement of all the bird species in Papahanaumokuakea, including Black-footed Albatross, Laysan Albatross, Frigatebirds, Christmas Shearwaters, Wedge-tailed Shearwaters, Bristle-thighed Curlews, Laysan Finch, and Laysan Duck. Surrounding the lake are over 30 kinds of plants. Native species of plants include Eragrostis (a bunch grass important for supporting bird burrows), Chenopodium (goosefoot), Ipomea (a morning glory), Sesuvium, and Makaloa (in which the laysan ducks and finches like to hide), and Mariscus (an endemic sedge on the endangered species list). Photo by Jennifer Palmer