Necker Island (25° 34' N - 164° 42' W)

Geography

Necker Island is a small, fish hook-shaped basalt island, about 155 miles (250 km) northwest of Nihoa Island and 90 miles (145 km) east of French Frigate Shoals, with a land area of about 45 acres (0.16 km² ). The main portion of the island has a profile with five hills, the highest being about 276 feet (84 m) above sea level. A narrow spur extends about 200 yards (183 m) northward from the western end of the island. Where it joins with the main land mass, the spur, whose highest elevation is 156 feet (48 m) above sea level, forms a shallow, rocky cove called Shark Bay.

Necker Island is the second smallest of the Northwestern Hawaiian Islands (NWHI), but its surrounding marine habitats to depths of 328 feet (100 m) totals 380,048 acres (1538 km2), the second largest in the NWHI. Shallow water marine habitats to depths of 66 feet (20 m) are limited to the vicinity of the island. Deeper shelves, which are offshore commercial fishing grounds, extend many miles from the island, especially in the southeastern direction.

Early human visitation

Necker Island was visited by Polynesians sometime before 1300 A.D. Over 50 cultural sites were discovered on the island, which include ruins of ceremonial stone structures (heiau) and over a dozen carved stones. It was "rediscovered" and named in 1786 by Jean Francois de Galaup.

Terrestrial vegetation

In suitable locations, the island is sparsely carpeted with five species of low, nearly prostrate plants: a species of goosefoot shrub (Chenopodium sandwicheum), a bunch grass (Panicum torridum), purslane (Portulaca lutea), pickle weed (Sesuvium portulacastrum), and the ohai shrub (Sesbania tomentosa). Necker Island provides a nesting spot for thousands of sea birds.

Reef biology

With regard to reef and coral development, Necker Island somewhat resembles Nihoa. It is a small island, vulnerable to strong wave action from any direction. The scoured shallow flat surfaces are unfavorable for coral growth. Most corals were found in habitats which are at least partially protected from wave scour, such as caves, overhangs, and trenches. Sixteen species of stony coral have been reported from Necker Island, a number somewhat comparable to Nihoa. The most commonly encountered species of stony coral were Pocillopora meandrina and Porites lobata. Corals found at Necker and not reported from Nihoa were Porites compressa, Pocillopora ligulata, and the corrugated coral, Pavona varians.

Shark Bay hosts a benthic community dominated by a variety of large, abundant algae. Reef fish assemblages at Necker appear healthy and abundant, very similar to those found at Nihoa and the Main Hawaiian Islands. Grey reef sharks, giant Trevally jacks, gray snappers, monk seals, and other predators have been reported. Several large manta rays have also been observed. Numerous limpets inhabit the island's rocky surf zone. Necker also supports a small population of endangered Hawaiian monk seals with limited reproduction, probably maintained by immigration from other breeding colonies. Necker Island also provides a nesting spot for thousands of sea birds.

Link to metadata and data held by CoRIS

Click on the following URL to locate and access metadata and data in the CoRIS holdings on Necker Island. When the query screen comes up, enter “Necker” in the window, and then click on “Search.”

http://coris.noaa.gov/data/