CRAMP Study Sites: Na Pali Sector, Island of Kaua‘i
Geographic Location: Sea cliffs between Barking Sands in the south to Kē‘ē in the north. Sector extends from Polihale 22° 05.884‘ N; 159° 44.781‘ W in the southeast to Kaililu Point 22° 13.409‘ N; 159° 34.925‘ W in the northwest.
Chart showing Na Pali coastline. Red arrows show location of transect sites. (Click image for larger view.)
Commercial boat tour off Na Pali Coast. Photo by Paul Jokiel. (Click image for larger view.)
The entire coastline consists of steep basaltic sea cliffs undergoing continual erosion by high wave impact. Faulting and extensive erosion of the shoreline has produced numerous hanging valleys along the coast. Eroded material is transported into deep water which lies very close to shore.
Reef Structure, Habitat Classification:
Most of the substrate is basaltic hard bottom and boulder habitat with occasional sand channels. Vertical walls, pinnacles, caves and ledges are found along this coast. A limited amount of carbonate reef flat occurs at Nu‘alolo Kai and Miloli‘i.
Precipitation along this coast is high (40-50 inches per year) with the winter months having somewhat higher rainfall. The prevailing NE Trade Winds are deflected by the island and tend to move parallel to the shoreline from NE to SW. Winds diminish at night, but increase again after 0900. Winds diminish again in late afternoon.
The dominant oceanographic factor controlling reef structure is extreme wave energy. This coastline is under the full impact of the winter North Pacific Swell and NE Trade Wind generated swell. Surface currents along the coast are influenced by permanent oceanographic flow modified by wind and tide. Prevailing large scale currents and NE Trade Winds drive the surface water to the SW. However, tidal currents reverse with the tidal cycle. During flood stage the tidal current along this coast tends to be from the northeast. Ebb current tends to be from the southwest (Laevastu et al, 1964). The presence of deep ocean water close to shore coupled with high wave energy and strong currents results in near oceanic water quality along this shoreline under most conditions.
Adjacent Land Use and Influence:
Na Pali Coast State Park occupies 6,175 acres along this coastline. The watershed is largely in conservation and forestry reserve. The coastline is rich in historical and cultural sites. Heiau (temples), ancient farming terraces, house platforms and burial caves are found in valleys along the coast. The coastal region is used for recreation and is accessible by trail and by sea. Commercial helicopter tours along the coast and commercial boat excursions are quite popular. Hiking, fishing, camping, and seasonal goat hunting are major activities. Uncontrolled populations of goats along inaccessible portions of the coastline result in overgrazing and accelerated sedimentation of the reefs.
Human Use Patterns:
In general, this coastline is used for recreation and fishing activity with a mix of commercial and private components. Commercial boat tours to the Kalalau valley, Nu‘alolo Kai, and Miloli‘i are available. Commercial kayak tours are also popular, leaving from Haena and taking advantage of the prevailing wind and current to carry the groups southwest to Polihali. The boating season generally runs from from May 15 through September 15. Landing permits are not granted outside of this season due to the danger of large winter surf. High surf from the north swell during the winter months creates hazardous surf and strong rip currents.
Hiking and camping are major activities. The trailhead for the Kalalau Trail is located at end of Kuhio Highway in Haena State Park. The trail follows scenic sea cliffs and valleys along the coastal Kalalau Primitive recreational experience. Short day hikes to Hanakāpī‘ai (2 miles one-way) are popular activities with the public. A more demanding hike is the 11-mile backpacking trip to a primitive camp at Kalalau valley with optional overnight stopovers at Hanakāpī‘ai and/or Hanakoa. The Kalalau trail traverses high sea cliffs and lush stream valleys with plunging waterfalls. The trail to the falls and beyond Hanakāpī‘ai is recommended for experienced hikers only.
Primitive camping facilities are provided at Miloli‘i which can be reached only from the sea. Boat landing is restricted, so boaters should first obtain information from the State Park office.
Economic Value and Social Benefits:
This coastline draws a considerable number of visitors to Kaua‘i and is an important component of the total Kaua‘i visitor experience. The tourist industry provides much of the economic base for Kaua‘i as evidenced by the economic hardship that resulted from lack of visitors following Hurricane Iniki.
Status (Degree of Legal Protection):
Unrestricted open access along entire coastline. Boat landings are restricted seasonally. The adjacent land areas are managed as a State Park with two of the valleys (Hono O Na Pali and Kuia) being administered as part of the Natural Area Reserve System.
The major management concern has been overcrowding and overuse of this area by visitors. Anchor damage and reef walking at the limited areas where visitors can come ashore have been noted as possible problems. Feral goat populations often increase to the point of causing severe overgrazing with subsequent land erosion and increased sedimentation on the offshore reefs. Some areas along this coast may be subject to heavy fishing pressure seasonally (especially in gathering of Opihi). However, the low human population on Kaua‘i, remoteness of the Na Pali Coast and severe winter wave conditions result in low fishing activity compared to many other areas of the state. Human impact on ancient cultural features is a concern.
Noteworthy Biota or Ecological Conditions:
Numerous sites along the coast are of special interest. The Mana Crack offshore has a structure reminiscent of a submerged barrier reef. Specimens of the coral Acropora cytherea are reported from this area. A carbonate reef flat off Nu‘alolo Kai has the structure of a growing coral reef, but may actually be a lithified dune deposit. Sea caves, pinnacles and ledges provide interesting biotic environments along this coastline.
Historical and Cultural Importance:
Numerous archaeological sites occur along this coastline in areas accessible from the sea. The Na Pali Coast Archaeological District is listed on the National and State Register of Historic Places. The entire coastline is in conservation status and allows one to experience an area that has been largely unaltered since first Western contact. Studies along this coastline are revealing the relationship between ancient Hawaiians and their environment.
Relevance of Location to CRAMP:
This coastline affords an accessible location for studies of the ecology of a high-wave energy north facing coastline characterized by sea cliffs and vertical submarine walls. This is an important coastal type found throughout much of the state (e.g. North Coast of Moloka‘i, SE Lāna‘i, SE Kaho‘olawe, N Maui, N and E Hawai‘i). Studies here will shed light on the ecology of this very important, but generally inaccessible, environment.
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