CRAMP Study Sites: Island of Kaho‘olawe
Figure 1: Map of Kaho‘olawe ili (land divisions).
Geographic Name: Kaho‘olawe
CRAMP site code: ke
Geographic Location:(20°35’N 156°35’ W ) The island of Kaho‘olawe is located in the Hawaiian Archipelago, about 11 km (7 miles) southwest of Maui and 18 km (18 miles) southeast of Lāna‘i.
WARNING! Kaho‘olawe and its surrounding waters contain unexploded ordnance, which are hazardous to public health and safety. Unauthorized entry onto the island of Kaho‘olawe and into the waters within two miles of Kaho‘olawe is prohibited (H.A.R. §13-260). However, there are opportunities for access. For more information explore the KIRC web site.
Figure 2: Chart of Kaho‘olawe
Kaho‘olawe is approximately 18 km (11 miles) long and 10 km (7 miles) wide and 116.5 km² (45 square miles) in area, the smallest of the eight main Hawaiian Islands. The highest point on Kaho‘olawe is Luamakika, with an elevation of 450 m (1477 feet) above sea level. Kaho‘olawe was formed by extrusions of thin pahoehoe lava flows from a small summit crater, near the current summit of Pu‘u Moaulanui, and three rift zones. At the end of the initial volcanic phase, Kaho‘olawe was part of a single large island that included Maui, Lāna‘i , and Moloka‘i. Subsequent erosion and changes in sea level separated this island from its neighbors. Rainfall and waves continue to erode the northern slopes, while wave erosion formed steep sea cliffs on the western and southern coasts (Sterns, 1940).
The steep cliffs of the south coast are continually being undercut by severe wave impact. NE Trade Winds accelerating through the Alenuihāhā Channel generate NE Trade Wind Waves that impact this coast. In addition, the coastline is impacted by South Swell and Kona Storm Waves. Seaward slopes are very steep. The 100 fathom depth contour lies within 0.5 nautical miles of the south coast. In contrast, the 100 fathom mark lies over 2.5 nautical miles from the north and west coastline. The western end of the island shows a gentler offshore slope and has several large calcareous sand beaches. The northern coastline is protected from the North Pacific Swell by the islands of Maui, Lāna‘i and Moloka‘i. This part of the island is cut by deep gullies and valleys. The north coast receives most of the runoff from the island and the reefs along this shoreline have been subjected to the highest levels of sedimentation. The eastern end includes the remnants of the large caldera formed by collapse of the summit of the volcano that created the island.
Figure 3: Graph of cumulative number of goats removed from Kaho‘olawe during eradication program 1971-1993. (Click image for larger view.)
Prior to the first Western contact, the island was covered with thick layers of lateritic soils. Beginning in the 19th century overgrazing by introduced goats and other livestock destroyed the protective vegetation. As a result, strong winds and rain erosion removed vast quantities of soil (Sterns, 1946; Kaho‘olawe Island Conveyance Commission, 1991, 1993). Total annual soil loss has been estimated at close to 1.8 x 109 kg (2 million tons) of soil per year (Kaho‘olawe Island Conveyance Commission, 1991). The top one third of the island was reduced to hardpan while the reefs and coastal waters were damaged by silt runoff. In 1971 a series of revegetation efforts by the State of Hawai‘i, the Protect Kaho‘olawe Ohana and other conservation organizations began. Reductions in the area of exposed soil was already evident by 1992 (Jones, 1992). The U.S. Navy completely eliminated the goats on the island by 1992 (Lt. Michael Naho‘opi‘i, U.S. Navy, Kaho‘olawe Project Coordinator, pers. comm.). With removal of the feral grazing animals the vegetation is continuing to recover though large areas of hardpan remain.
Reef Structure, Habitat Classification:
Figure 4: The northern coast of Kaho‘olawe. Photo by Paul Jokiel. (Click image for larger view.)
The northern coast is characterized by deeply eroded gullies and valleys. The valleys are drowned at their lower end. Wave action has led to undercutting and erosion of the valley ridge headlands into low rocky cliffs, interspersed with numerous small beaches (Figure 3). A relatively shallow shelf extends offshore. The numerous valleys and gulches along this coast transport soil down from the upper slopes. The offshore extensions of these valleys hold deep deposits of terrestrial sediments. Turbidity can be high after rains or when waves resuspend bottom sediments. The trade winds increase during the day, driving surface currents to the SW and resuspending inshore sediments. Sediment plumes move out of the bays and along the coast to the SW. Along the SW headland of each submerged valley chronic turbidity and lowered salinity during rains results in low coral coverage. High macroalgae standing crop occurs on the down current areas suggesting that nutrients as well as sediments are carried out of the valleys. There is a sharp demarcation between the turbid waters of the sediment plumes along the downstream (SW) edge of these areas and the clearer waters along the NE shores of the submerged valleys. Porites compressa and several species of Montipora, dominate these areas of high coral coverage.
The eastern end of Kaho‘olawe includes the highest point on the island (Luamakika at 1477 ft elevation) and remnants of the large caldera which formed after the summit collapsed. The presence of faults and dikes in this region led to slumping and the formation of a large bay, Kanapou. Evidence of post-caldera volcanic eruptions is visible on these cliffs. This bay is exposed to waves moving through the Alenuihāhā Channel and into the Alalākeiki Channel, and much water-borne debris collects on the beaches. Although wave energy from NE Trade Wind waves is high, the area is protected from South Swell and Kona Storm Waves. As a result, the coral communities in deeper water are relatively diverse and coverage is moderate.
Figure 5: The southeastern portion of Kaho‘olawe showing the steep cliff of the south shoreline and Kamohio Bay. Farther in the distance is the eastern shore and Kanapou Bay. The highest elevation is Lua Makika. Photo by Paul Jokiel. (Click image for larger view.)
The southern coast consists of steep cliffs with two large bays and several hanging valleys. The sea floor is littered with large boulders and slopes quite steeply away from the shoreline. Terrestrial sedimentation enters the sea during rainy periods from the hanging valleys along the coastline, but strong currents and waves dissipate the plumes and carry away the fine sediment. There are wave-protected habitats with high coral coverage within the two large bays, Kamōhio and Wai Kahalulu.
Figure 6: The western portion of Kaho‘olawe has lower relief, little erosion and sandy beaches. NOAA photo. (Click image for larger view.)
The western end of the island has two large beaches, Hanakanai‘a (Smuggler’s Cove) and Keana a ke Keiki (Twin Sands), separated by Lae o Kealaikahiki, "The Way to Tahiti", a point of departure for sailing voyages to distant lands. A wide shelf containing remnants of Black Rock and Kuia Shoal extends offshore from Lae o Kealaikahiki. This portion of the island is subjected to South Swell and Southwest Kona Storm Waves so coral coverage is low. Coral communities are dominated by Pocillopora meandrina and Porites lobata.
Oceanographic and Meteorological Conditions:
Wind patterns in the Hawaiian Islands are dominated by the northeast trade winds produced by the Pacific High northeast of Hawai‘i (University of Hawai‘i, Geography Department, 1983). The trade winds are most prevalent (80 to 95%) during the "summer", from May through October. During the "winter", from October through April, trade winds still dominate the wind patterns but are present less frequently (50 to 80%). Haleakalā on the island of Maui deflects and funnels trade winds to the east across Kaho‘olawe at speeds of 8.2 - 9.3 m sec -1 (16 to 18 knots). The strong and persistent trade winds have contributed to severe erosion of Kaho‘olawe in the last 150 years after grazing by introduced livestock destroyed most of the covering vegetation. Numerous reports describe large dust clouds blowing off the island (Judd, 1917; Environmental Impact Study Corp., 1979).
The island of Kaho‘olawe lies in the rain shadow of Maui and is of low elevation. Consequently the island is relatively dry. Few data from the historical period exist, but average annual rainfall is about 63 cm (25 in) (Environmental Impact Study Corp., 1979). Most of the rainfall on Kaho‘olawe occurs during winter storms, when winds blow from the south. Rainfall produces great plumes of eroded sediment in the nearshore waters around the island.
Surface runoff on Kaho‘olawe is estimated at 7 x 107 m3 (19 billion gallons) per year (County of Maui, 1990). At present, this surface water has an extremely high sediment load due to the lack of vegetation and consequent high rates of erosion. Flood tidal currents follow the patterns of the prevailing trade wind currents, diverging around the eastern end of the island and converging off the southwest coast at Lae o Kealaikahiki. At ebb tide the direction of the tidal current reverses, although the net effect due to the over-riding importance of the wind-driven surface current is flow southward along the coast (Environment Impact Study Corp., 1979). This prevailing offshore water flow pattern at the western tip of the island favored the start of long voyages to the south by ancient Hawaiians and thus was called "The Way to Tahiti".
Adjacent Land Tenure, Land Use:
The entire island is in reserve status and undergoing extensive restoration and ordnance clearance. Personnel involved in the clearing operation are housed in the former military base at "Smuggler‘s Cove" at the western end of the island. Groups visit the island for educational, cultural and religious activities. Generally the visits involve less than 30 persons and occur once per month at Hakioawa.
Access to the marine environment is restricted, except for one weekend per month when trolling is allowed within the reserve. Fishing is allowed in certain locations, but only for consumption on island by visiting groups. A very limited amount of fishing activity takes place at Hakioawa during the monthly cultural and educational visits.
Economic Value and Social Benefits:
Kaho‘olawe is a valuable cultural, educational and research resource. Long range plans are in effect for eventual expansion of these programs. Restriction of fishing has produced the largest and best enforced marine protected area in the State of Hawai‘i at a time when most of the main Hawaiian Islands are being heavily over fished. The fish stocks of Kaho‘olawe could be an important source of fish larvae for the replenishment of reef fish on other nearby islands.
Status (Degree of Legal Protection):
Kaho‘olawe is a reserve under the management and control of the Kaho‘olawe Island Reserve Commission (KIRC) established by Chapter 6K of the Hawai‘i Revised Statutes. Unauthorized entry onto the island of Kaho‘olawe and into the waters within two miles of Kaho‘olawe is prohibited. However, there are opportunities for access. For more information see the KIRC web site and/or call the Kaho‘olawe Island Reserve Commission (KIRC) on O‘ahu at (808) 586-0761.
Figure 7: Unexploded ordnance (UXO) that has accumulated on Kaho‘olawe over decades of military target range activity includes bombs, artillery shells, rockets, mortar rounds, land mines and numerous types of anti personnel explosive devices. Photo of deactivated ordnance at the Smuggler‘s Cove Military Base Camp, 1993 by Paul Jokiel. (Click image for larger view.)
The removal of unexploded ordnance is the major concern at the present time. Controlling soil erosion has been a matter of considerable effort. Preservation and restoration of the environment and cultural features are also important. Unlike the other main Hawaiian Islands, Kaho‘olawe has never had a large permanent population or modern large-scale agriculture. The nearshore environment has not been subjected to some of the multiple anthropogenic factors impinging on reefs of the other major islands. The reefs of Kaho‘olawe were subjected to extreme sedimentation as a result of the uncontrolled goat grazing, fires and impact damage rustling from use of island as a military target range. As revegetation occurs and sediment input diminshes, these reef areas are slowly undergoing recovery from sediment effects. Enforcement of the closure of Kaho‘olawe was not enforced prior to KIRC administration and as a consequence the area was heavily fished. This situation has been resolved through a good enforcement program.
Noteworthy Flora and Fauna:
There is a wide range of reef habitats and high diversity of corals and fishes in the existing coral reef areas around Kaho‘olawe. In spite of the heavy sediment input, some areas are near pristine and show minimal impacts of human activities. The presence of a high island reef system not impacted by fishing, agriculture, industry, and urbanization is a unique scientific resource for comparison to other areas of Hawai‘i and for monitoring global changes. The man-made anchialine pond at Sailor‘s Hat Crater represents a unique resource in the Hawaiian Islands. The shrimp opae ula is a fugitive species that cannot tolerate the high level of predation found in most Hawaiian aquatic systems. Kaho‘olawe represents an important refuge for this species. The nearshore waters of Kaho‘olawe provide habitat for sea turtles, spinner dolphins, and monk seals. Kaho‘olawe contains specific habitats for these animals (especially potential for turtle nesting and pupping areas for seals).
This island is of great significance to Native Hawaiians, and serves as an important natural area and cultural reserve for all the people of Hawai‘i. The Kaho‘olawe Island Reserve (KIR) was established to preserve and promote the practice of Native Hawaiian cultural, spiritual and subsistence practices. KIRC us working to preserve Kaho‘olawe‘s archeological and historical resources in addition to protecting environmental resources, conducting habitat restoration and providing an important means of education (Dames and Moore, 1997). Ancient chants and archaeological evidence indicate Kaho‘olawe was inhabited for over a thousand years. Hawaiians fished, farmed, and lived in coastal and interior settlements across the entire island. In ancient times the island was called Kanaloa for the god of the ocean and the foundations of the earth. It was a place where kahuna and navigators were trained and it played an important role in early Pacific migrations. Today, Kaho‘olawe serves as a foundation for the revitalization of Hawaiian cultural practices.
Scientific Importance and Research Potential:
Fishing restrictions are now being heavily enforced, so Kaho‘olawe fish communities will be returning to a near pristine condition. This is one of a very few sites in Hawai‘i where unfished reef populations can be documented. In the future, Kaho‘olawe can be used as a site to document effect of different fishing regimes (closed reserve vs. traditional methods vs. modern techniques) on reef fish populations.
ICE Case Study: Hawai‘i and the Military. http://www.american.edu/ted/ice/hawaiibombs.htm
Protect Kaho‘olawe Ohana. http://www.brouhaha.net/ohana/
County of Maui. Department of Water Supply. 1990. Maui County Water Use and
County of Maui. Department of Water Supply. 1990. Maui County Water Use and Development Plan.
Dames and Moore (1997) OLA I KE KAI O KANALOA. KAHO‘OLAWE OCEAN MANAGEMENT PLAN. Prepared for the Kaho‘olawe Island Reserve Commission. 84 pp. Available online at: http://www.state.hi.us/kirc/plans/komp.doc
Environment Impact Study Corp. 1979. Environmental Impact Statement, Military Use of Kaho‘olawe Training Area, Hawaiian Archipelago. Prepared for the Department of the Navy, September 1979.
Jones, R.A. 1992. Kaho‘olawe GIS (Geographic Information System). Kaho‘olawe Island Conveyance Commission Consultant Report No. 10. 16 pp.
Judd, C.S. 1917. Kaho‘olawe. Hawaiian Almanac and Annual 1917:117-125.
Kaho‘olawe Island Conveyance Commission. 1991. Interim Report to the United States Congress.
Kaho‘olawe Island Conveyance Commission. 1993. Kaho‘olawe Island: Restoring a Cultural Treasure. Final Report of the Kaho‘olawe Island Conveyance Commission to the Congress of the United States. 158 pp.
Sterns, H.T. 1940. Geology and ground-water resources of the islands of Lāna‘i and Kaho‘olawe, Hawai‘i. US Geological Survey Bulletin 6:119-147.
Cox EF, Jokiel PL, Te FT, Stanton FG, Naughton J, Brock RE and Bailey-Brock JH (1995). An Evaluation of the Nearshore Coral Reef Resources of Kaho‘olawe. Hawai‘i Institute of Marine Biology Technical Report No. 40, Honolulu, Hawai‘i. June 1995. Final Report Submitted to: The National Oceanic and Atmospheric Administration. NOAA Cooperative Agreement No. NA27OM0327. 90 pp.
Last Update: 04/21/2008
By: Lea Hollingsworth
Hawai‘i Coral Reef Assessment & Monitoring Program
Hawai‘i Institute of Marine Biology
P.O. Box 1346
Kāne‘ohe, HI 96744