Home > Islets > Oahu > Mokulua ISLETS: OAHU > MOKULUA Mokulua   North & South Mokulua - Photo: C Swenson Mokulua North - Photo: C Swenson   Mokulua North - Photo: F & K Starr Mokulua North - Photo: F & K Starr   Mokulua South - Photo: F & K Starr Physical Features Mokulua translates as ‘two islands’ and is, indeed, made up of two volcanic islets; Moku Nui or North Mokulua and Moku Iki or South Mokulua. Together, they total 24 acres in size and reach elevations of 225 and 150 feet, respectively. They are located approximately 3/4 of a mile offshore from Lanikai. Both are remnants of the dike core of the Kailua Volcano, overlain by lava from subsequent Koolau eruptions. North Mokulua has two peaks and is the larger of the islets. It is separated from South Mokulua, which has only one peak, by a shallow channel 200 feet wide. Both islets have steep slopes, cliffs, and rocky shores. The sandy west beach of North Mokulua, however, is suitable for landing in good weather and is the destination of thousands of kayakers and other visitors coming across from Kailua each year. Regulations Both Mokulua islets are State Seabird Sanctuaries managed by the Hawaii DOFAW. Regulations in Hawaii Administrative Rules, Title 13 Chapter 125, protect wildlife and plants and restrict human activities in seabird sanctuaries. Federal law also protects seabirds, shorebirds, and threatened or endangered species. Visitors must obey all posted signs and stay away from the interior of the islets, where dense concentrations of seabird burrows occur. Birds Wedge-tailed shearwaters nest on North and South Mokulua. A 2000 survey estimated almost 15,000 breeding adult shearwaters on both islets. In 1941, Bulwer's petrels were reported to be more common on Mokulua than on any other Oahu offshore islet. Today, however, they nest in small numbers on both islets. A 1941 survey observed small numbers of black noddies nesting on the eastern cliffs of North Mokulua, but they have not been observed since. Surprisingly, Hawaiian ducks, now listed as an endangered species, nested in small numbers on North and South Mokulua until the early 1940s. In 2000, heavy rains and erosion of unvegetated soil collapsed and filled in many burrows, killing seabird chicks trapped inside. This event highlighted the need for vegetation restoration as a means of seabird colony restoration. Plants Vegetation cover on both Mokulua islets is primarily alien but some native species remain. A 2005 survey recorded 37 plant species on North Mokulua, 17 of which were native. The same survey documented 42 plant species on South Mokulua, including 18 native species. Non-native grasses, especially Cenchrus echinatus (Beach Cenchrus), dominate many areas but native species are present near coastlines and in windward areas. Drought and soil erosion have been periodic problems. As a result, Hawaii DOFAW and OIRC have been working on outplanting native vegetation to stabilize the islet. For example, the Natural Resource Conservation Service’s Molokai Plant Materials Center has supplied bales of native pili grass (Heteropogon contortus) that have been dropped by helicopter to control soil erosion through a combination of re-seeding and physical erosion control. In 2003, the U.S. Fish and Wildlife Service designated critical habitat on both North and South Mokulua for the endangered plant, Chamaesyce kuwaleana. Although this plant is not present, establishing populations on both islets would be an important step towards species recovery. Insects A University of Hawaii study is examining the effects of alien ants on nesting seabirds on North and South Mokulua. Several species of ants, including big headed ants, crazy ants (Paratrechina longicornis), and fire ants (Solenopsis geminata), are common. Intensive insect collecting associated with this project has shown that most insects on Mokulua are alien, although the rare, Native Yellow Faced Hylaeus Bee is still present. Part of the project included a 2002 experimental broadcast of toxic ant bait on North Mokulua, which was then compared to untreated South Mokulua. The bait eradicated crazy ants and significantly reduced fire ants on North Mokulua, resulting in decreased ant attacks on the shearwaters and increased health of some native plants. Marine Organisms Rocky tidepools and intertidal areas are common around both islets. Threatened Green sea turtles (Chelonia mydas) are often seen in the waters around the islets. Human Uses The sandy beach at North Mokulua is a destination for thousands of kayakers, surfers, and boaters every year. Multiple commercial operations cater to the Mokulua-bound kayakers and provide a spectrum of services ranging from simple equipment rental to guided ecotours. While this situation presents ecological risks, it also provides an opportunity to educate the public about coastal conservation. In 2005, students from Lanikai Elementary School designed and posted signs on the North Mokulua beach, describing the islet ecosystem and how the public can help to preserve it. Threats Heavy human use poses threats of seabird disturbance and the introduction of new alien species. Soil erosion, invasive weeds, and ants all create problems for nesting seabirds and other species. Rats were suspected to be present in the 1930s and 1940s but were never documented. However, high levels of visitation create a constant risk of introducing rodents. > Back to top of page Home  Islets  Species  Projects  Outreach  Links  About Us