Prepared in cooperation with the U.S. National Park Service

Benthic Habitats and Offshore Geological Resources of

Kaloko-Honoko–hau National Historical Park, Hawai`i

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2006–5256

Version 1.1, May 2016

Kaloko Fishpond

Kaloko Point
Cover: Left, enlarged portion of benthic habitat map showing Kaloko-Honok–ohau National Historical Park shoreline. Right, underwater photograph shows 

example of coral reef habitat on the Kona coast of Hawai`i.
Benthic Habitats and Offshore Geological Resources of

Kaloko-Honok–ohau National Historical Park, Hawai`i

By Ann E. Gibbs, Susan A. Cochran, Joshua B. Logan, and Eric E. Grossman

Prepared in cooperation with the U.S. National Park Service

Scientific Investigations Report 2006–5256

Version 1.1, May 2016

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

SALLY JEWELL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Director

U.S. Geological Survey, Reston, Virginia: 2016

First release: 2007

Revised: May 2016 (ver. 1.1)

This report and any updates to it are available at: http://pubs.usgs.gov/sir/2006/5256

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Manuscript approved for publication, November 13, 2006

Text edited by Peter H. Stauffer

Layout by David R. Jones

Suggested citation:

Gibbs, A.E., Cochran, S.A., Logan, J.B, and Grossman, E.E., 2007, Benthic habitats and offshore geological resources 

of Kaloko-Honok–ohau National Historical park, Hawai`i (ver. 1.1, May 2016): U.S. Geological Survey Scientific 

Investigations Report 2006–5256, 62 p.

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the 

U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.
iii

Contents

Executive Summary.......................................................................................................................................1

Geologic Framework ............................................................................................................................1

Benthic Species....................................................................................................................................2

Benthic Habitat......................................................................................................................................2

Coral Distribution ..................................................................................................................................2

Status of the Habitat.............................................................................................................................2

Special Considerations and Recommendations..............................................................................2

Introduction ....................................................................................................................................................3 

Study Area.......................................................................................................................................................3

General Setting......................................................................................................................................3

Wave Climate.........................................................................................................................................5

Previous Efforts..............................................................................................................................................7

Data and Methods .........................................................................................................................................7

Background Data..................................................................................................................................9

Aerial Photography......................................................................................................................9

SHOALS Bathymetry ...................................................................................................................9

Acquired Data......................................................................................................................................11

Underwater Video and Still Photography .......................................................................................11

Video Mosaics............................................................................................................................14

Benthic Habitat Mapping Using GIS................................................................................................14

Classification Scheme ..............................................................................................................15

Accuracy Assessment..............................................................................................................16

Data Archive........................................................................................................................................16

Results ...........................................................................................................................................................16

Benthic Species..................................................................................................................................16

Benthic Habitats..................................................................................................................................17

Geologic Framework and Habitat Zones ...............................................................................17

Shoreline/Intertidal...........................................................................................................23

Dredged..............................................................................................................................23

Shallow Bench (Narrow, Broad)....................................................................................24

Shallow Cliff.......................................................................................................................25

Intermediate Bench..........................................................................................................25

Shelf Break ........................................................................................................................26

Shelf Escarpment..............................................................................................................26

Deep Bench .......................................................................................................................26

Deep Cliff............................................................................................................................26 

Pinnacles/Ridges ..............................................................................................................28

Deep slope .........................................................................................................................29

Regional Patterns of Coral Cover............................................................................................29

North Bench/Escarpment................................................................................................29

Pinnacles............................................................................................................................32

West Bench .......................................................................................................................37

Central Bench/Escarpment.............................................................................................38

Harbor Embayment ..........................................................................................................44
iv

South Bench/Escarpment ...............................................................................................45

Discussion.....................................................................................................................................................51

Coral Zonation and Importance of Natural Disturbances on Coral Habitat..............................51

Status of the Habitat...........................................................................................................................52

Ages of Submerged Volcanics and Sea-Level History.................................................................52

Unique Underwater Features ..........................................................................................................54

Accuracy of Maps ..............................................................................................................................55

Special Considerations and Recommendations for Future Work...............................................55

Acknowledgements.....................................................................................................................................56

References Cited..........................................................................................................................................57

Appendix 

Detailed Classification Scheme ................................................................................................................59

Figures

1. Location map............................................................................................................................................4

2. Map showing land use around Kaloko-Honoko–hau NHP circa 2006 ..............................................5

3. Aerial photomosaic showing volcanic flows within Kaloko-Honoko–hau NHP..............................6

4. Diagram illustrating primary wave patterns for the main Hawaiian Islands.................................7

5. Example from the KAHO area of the photography and benthic habitat maps produced 

and used by the National Oceanic and Atmospheric Administration’s (NOAA) 

Biogeography Program for the main eight Hawaiian Islands..........................................................8

6. Flowchart illustrating methodology used to create the habitat map..............................................9

7. Aerial photomosaic showing the mapped area, the coverage area of 

SHOALS bathymetry, the offshore limit of interpretable aerial photography, and 

the KAHO park boundary......................................................................................................................10

8. Comparison of aerial photomosaic (left) and Quickbird satellite imagery (right) 

of the KAHO park area..........................................................................................................................11

9. Aerial photomosaics of the KAHO park area overlain with bathymetry data .............................12

10. Aerial photomosaic of the KAHO park area overlain with video trackline locations ................13

11. Photograph of the Alyce C of Moloka`i heading out of Ma–`alaea Harbor, Maui.........................14

12. Photograph of the SEAVIEWER camera system (A) rigged to collect towed video, 

and (B) with SeaBird CTD acquisition system rigged to collect drop video and CTD 

information.............................................................................................................................................14

13. Photograph of shipboard laboratory set-up for navigation, recording of ship’s 

position, and feature annotation........................................................................................................14

14. Example from KAHO park of an underwater video mosaic overlaid on aerial 

photography...........................................................................................................................................15

15. Schematic diagram showing the generalized cross-shelf coral reef zonation..........................16

16. The maximum percentage of the nine coral species quantified from all 

Rapid Assessment Transect (RAT) surveys......................................................................................17

17. Benthic habitat map of Kaloko-Honoko–hau area draped on shaded relief bathymetry............18

18. Map showing the distribution of percent coral-cover classes in the KAHO 

area draped on shaded relief bathymetry........................................................................................19
v

19. Relative abundance of major and dominant substrate structures, major 

biological coverage on coral reef and hardbottom, and percent hard coral 

cover on available hardbottom in the KAHO study area................................................................20

20. Bar graph showing the percent coral cover by depth....................................................................20

21. Sea-floor slope map illustrating the complexity of the sea-floor surface and 

the variety of sea-floor structures within KAHO .............................................................................21

22. Delineation of the twelve habitat zones described in the text, overlaid on 

shaded relief bathymetry.....................................................................................................................22

23. Representative photos of the shallow bench habitat zone............................................................23

24. Representative photos of the intermediate bench habitat zone ...................................................24

25. Representative photos of the shelf break and shelf escarpment habitat zones ........................25

26. Map of fathometer tracklines and selected profiles in the KAHO area showing 

variation in offshore morphology.......................................................................................................27

27. Representative photos of the shelf break and shelf escarpment habitat zones ........................28

28. Representative photos of the pinnacles/ridges habitat zone ........................................................29

29. Representative photos of the deep slope habitat zone...................................................................30

30. Cross-shelf profiles of the six regions described in the report .....................................................31

31. Habitat zones of the north bench/escarpment region of KAHO overlaid on 

shaded relief bathymetry.....................................................................................................................32

32. Benthic habitat classifications of the north bench/escarpment region of KAHO 

overlaid on shaded relief bathymetry................................................................................................33

33. Cross-shelf profile (A) and typical benthic habitat transitions of the north 

bench/escarpment region of KAHO...................................................................................................34

34. Three-dimensional perspective view of the north bench/escarpment region of 

KAHO, showing benthic habitat classifications draped on lidar bathymetry.............................34

35. Habitat zones of the pinnacles region of KAHO overlaid on shaded relief bathymetry ............35

36. Benthic habitat classifications of the pinnacles region of KAHO overlaid on 

shaded relief bathymetry.....................................................................................................................36

37. Cross-shelf profile (B) and typical benthic habitat transitions of the pinnacles 

region of KAHO......................................................................................................................................36

38. Three-dimensional perspective view of the pinnacles region of KAHO, showing benthic 

habitat classifications draped on lidar bathymetry ........................................................................37

39. Habitat zones of the west bench region of KAHO overlaid on shaded relief bathymetry.........38

40. Benthic habitat classifications of the west bench region of KAHO overlaid on 

shaded relief bathymetry.....................................................................................................................39

41. Cross-shelf profile (C) and typical benthic habitat transitions of the west bench 

region of KAHO......................................................................................................................................39

42. Three-dimensional perspective view of the west bench region of KAHO, showing 

benthic habitat classifications draped on lidar bathymetry..........................................................40

43. Habitat zones of the central bench/escarpment region of KAHO overlaid on shaded 

relief bathymetry...................................................................................................................................41

44. Benthic habitat classifications of the central bench/escarpment region of KAHO 

overlaid on shaded relief bathymetry................................................................................................42

45. Cross-shelf profile (D) and typical benthic habitat transitions of the west bench 

region of KAHO......................................................................................................................................43

46. Three-dimensional perspective view of the central bench/escarpment region of 

KAHO, showing benthic habitat classifications draped on lidar bathymetry.............................43
vi

47. Habitat zones of the harbor embayment region of KAHO overlaid on shaded 

relief bathymetry...................................................................................................................................45

48. Benthic habitat classifications of the harbor embayment region of KAHO 

overlaid on shaded relief bathymetry................................................................................................46

49. Cross-shelf profile (E) and typical benthic habitat transitions of the harbor 

embayment region of KAHO................................................................................................................46

50. Cross-shelf profile (F) of the ridges and sand channels located on the 

intermediate bench of the harbor embayment region of KAHO...................................................47

51. Three-dimensional perspective view of the harbor embayment region of KAHO, 

showing benthic habitat classifications draped on lidar bathymetry .........................................47

52. Habitat zones of the south bench/escarpment region of KAHO overlaid on shaded 

relief bathymetry. Hatched lines indicate areas lacking bathymetric data................................48

53. Benthic habitat classifications of the south bench/escarpment region of KAHO 

overlaid on shaded relief bathymetry................................................................................................49

54. Cross-shelf profile (G) and typical benthic habitat transitions of the south 

bench/escarpment region of KAHO...................................................................................................50

55. Three-dimensional perspective view of the south bench/escarpment region of KAHO, 

showing benthic habitat classifications draped on lidar bathymetry .........................................50

56. Schematic diagram of the physiographic zonation of coral communities along the 

Kona coast of Hawai`i..........................................................................................................................51

57. Photographs showing examples of the limited macroalgae and sea-stars 

observed in the study area..................................................................................................................53

58. Photographs showing examples of some unique underwater features and organisms 

observed in the stud area....................................................................................................................54

Tables

1. Major structure (substrate) types with dominant structure subdivisions ...................................15

2. Major biologic cover classes. Numbers represent UNIQUEID identifier.....................................16

3. Percent cover classes. Numbers represent UNIQUEID identifier.................................................16

4. Geomorphic zones of coral reef ecosystems ...................................................................................16

5. Species observed at Kaloko-Honoko–hau National Historical Park (KAHO) 

during Rapid Assessment Transect (RAT) surveys (Rodgers and others, 2004) .........................17

6. Total area and relative percentage of total area of the twelve habitat zones ............................23

7. Relative sea-level position, estimated subsidence amounts, and depth 

of the shoreline for the ages bounding the lava flows present in Kaloko-Honoko–hau 

National Historical Park (KAHO) .........................................................................................................54

8. Accuracy assessment matrix for the major biological cover classes. ........................................55

9. Accuracy assessment matrix for the percent of major biologic cover classes .........................56

10. Accuracy assessment matrix for the dominant structure classes...............................................57
Benthic Habitats and Offshore Geological Resources of

Kaloko-Honok–ohau National Historical Park, Hawai`i 

By Ann E. Gibbs, Susan A. Cochran, Joshua B. Logan, and Eric E. Grossman

to develop detailed benthic-habitat classification maps for 

the marine lands within and adjacent to the park. The intent 

of this project is to provide baseline maps and a Geographic 

Information System (GIS) database and description of the 

biological and geological resources of these marine lands 

in order to facilitate the management, interpretation, and 

understanding of park resources. 

A benthic-habitat classification map was created for 

the park using existing color aerial photography, Scanning 

Hydrographic Operational Airborne Lidar Survey (SHOALS) 

bathymetric data, georeferenced underwater video, and still 

photography. Individual habitat polygons were classified 

using five basic attributes: (1) major structure or substrate, (2) 

dominant structure, (3) major biologic cover on the substrate, 

(4) percentage of major biological cover, and (5) geographic 

zone. Additional information regarding geology, morphology, 

and coral species were also noted.

Geologic Framework

The offshore region of KAHO consists of multiple, 

coalescing volcanic flows that form distinct morphological 

regions and support diverse benthic habitats. The offshore 

geology is predominantly composed of smooth to undulating 

pahoehoe-type basalt flows that form flat to gently sloping 

benches, cliffs, and steep shelf escarpments. In some locations 

the basalt surface is irregular and mounded into ridges, 

pinnacles, and arches. Large rounded boulders and smaller 

scattered rocks are common throughout the park. In only a few 

locations does coral cover or accreted carbonate reef obscure 

the underlying volcanic surface. 

The upland area of the park is composed of three Holocene 

basalt flows that originated from Hualālai Volcano and range 

in age from 10 ka (thousand years) to 1.5 ka. The geologic 

history and ages of the submerged flows, however, are poorly 

constrained. In general, the surface of the submerged volcanic 

substrate shows textures commonly seen on subaerial flows 

(ropey pahoehoe, pinnacles, and tubes), suggesting that little 

erosion has occurred in these locations. However, the presence 

of the shallow and deep cliffs and the abundant, well-rounded 

boulders that cover much of the study area indicates that 

extensive erosion has been modifying the shape of the sea floor 

over an extended period of time. No features or morphology 

Executive Summary

Kaloko-Honokōhau National Historical Park (KAHO) is one 

of three National Park lands located along the western coast of the 

Island of Hawai`i and the only one to include submerged lands 

and marine resources within its official boundaries. The park was 

established in 1978 and is 1,160 acres in size, including 596 acres 

of marine area. The submerged lands are currently managed by 

the State of Hawai`i, Department of Land and Natural Resources, 

Division of Aquatic Resources (DLNR-DAR). KAHO is located 

adjacent to a moderately well developed area of the Kona coast. 

The park is bordered on the south by the Honokōhau small-boat 

harbor and on the north by a luxury residential/resort and golf 

course development currently (2006) under construction. A 

county landfill and wastewater treatment facility that discharges 

treated effluent are located within a mile upslope of the harbor 

and the park. Across the highway from the east boundary are a 

rock quarry and a light industrial and business district. Future 

development slated for lands adjacent to the south boundary of 

the park include a 300-percent expansion of the small-boat harbor, 

along with construction of hotels, condominiums, and a light 

industrial park. 

Marine resources located within KAHO include coral reef 

and habitat for many marine animals, including the green sea 

turtle and a variety of fish and invertebrates. In addition, many 

archeological, cultural, and recreational resources are located 

within the marine realm of the park. Potential threats and stressors 

to the modern marine environment include ground-water and 

surface-water contamination, invasive plants and algae, fishing 

pressure and use of monofilament gill nets (which can ensnare 

marine life or become tangled on reefs and be left behind as 

fishing debris), and visitor use impacts, such as scuba diving and 

snorkeling. Illegal dumping, oil releases, boat groundings, and 

other physical damage to reef resources are potential threats from 

users of the nearby harbor. Special issues of concern for the park 

include establishing baseline conditions of the offshore resources 

before the development of adjacent coastal lands. 

Until this study, only a general knowledge of the 

distribution of benthic habitats and the characteristics of the 

offshore region of Kaloko-Honokōhau National Historical Park 

was available. In 2003, a collaborative project between the 

U.S. Geological Survey (USGS) Coastal and Marine Geology 

Program and the National Park Service (NPS) was initiated 
2 Kaloko-Honok–

ohau National Historical Park, Hawai`i

that would indicate primary deposition underwater (for 

example, lava pillows) were observed, suggesting that the flows 

we observe today were originally deposited subaerially and 

have subsided to their present position below sea level.

Benthic Species

The reefs at KAHO are primarily Porites reefs, comprising 

mainly P. compressa and P. lobata; overall, four individual Porites

species were identified. A total of thirteen species of coral from 

nine genera were observed within the park. KAHO has a high 

abundance of the endemic octocoral, Anthelia edmonsoni. This 

species is common at many other locations on the west coast of 

the Island of Hawai`i, although relatively rare at most other sites 

within the State. Seven species of invertebrates were observed 

within the park, most commonly the collector urchin, Tripneustes 

gratilla, and the rock-boring urchin, Echinometra mathaei. The 

Crown of Thorns sea star, Acanthaster planci, was also observed 

at numerous locations within the park. 

Benthic Habitat

Benthic habitat varies greatly throughout the study area. 

Nearly 73 percent of the study area consists of a hardbottom 

structure that is potentially available for coral habitation; 

the remaining 27 percent includes unconsolidated sediment 

and artificial and artificial/historical features. Coral cover is 

predominantly low, with 68 percent of the total hardbottom 

area covered with 10 to <50 percent coral. Significant areas of 

moderately high (50 to <90 percent; 12 percent total hardbottom) 

and high (90 to 100 percent; 2 percent total hardbottom) coral 

coverage are also mapped within the study area. Generally, coral 

cover increases with depth, with the maximum at depths between 

about 10 and 20 m of water.

Coral Distribution

The coral cover in the park is low overall, except for areas 

that are relatively protected from high wave energy—in the

most deeply embayed reaches off the harbor mouth and off 

Kaloko Fishpond. In both of those areas, the coral communities 

are diverse, healthy, and thriving. The embayments are locally 

protected from south swell and Kona storms by Noio Point and 

from all but the most westerly north Pacific swell by Wawahiwa`a 

Point. Between the two, the deep bench and central bench/

escarpment regions provide additional protection from larger 

waves that shoal across the relatively exposed platforms. 

Status of the Habitat

Overall, the park’s offshore region supports a healthy 

and relatively diverse coral habitat. Little evidence of invasive 

macroalgae and no diseased coral were observed. However, a few 

limited occurrences of macroalgae were noted. Several specimens 

of the potentially destructive sea star Acanthaster planci were 

observed, although limited evidence for widespread destruction 

of coral suggests that these predators may be balanced within the 

ecosystem.

The only anomalous habitat area appears to be off the harbor 

mouth, where an area of low coral cover was mapped between 

some of the most abundant and diverse coral communities within 

the study area. The causes of this apparent degradation are unclear.

Low sedimentation rates, along with the dearth of invasive 

or native macroalgae and the presence of thriving, healthy reefs 

in protected locations, suggest that the coral habitat in KAHO is 

primarily controlled by natural wave-induced stresses, with little 

evidence of anthropogenic stresses. Areas of high visitor use, 

such as near the shoreline or around mooring buoys, were not 

specifically evaluated for impacts of the users.

Special Considerations and Recommendations

As results of the study reported in this work, the 

following observations and recommendations are given:

• The areas of highest coral cover within the park are located 

adjacent to the most highly developed (developing) areas of 

adjacent coast—offshore Honokōhau Harbor and Kaloko 

Fishpond. We recommend that the NPS establish long-term 

monitoring stations near these locations to evaluate any 

changes in environmental conditions (sedimentation, water 

quality, direct impact) that may adversely affect the habitats in 

the future.

• Establish coral and water-quality monitoring and currentmeasurement transects near the poorly colonized area off 

the harbor mouth and control area(s) in order to determine 

whether potential changes in sedimentation, water quality, or 

bottom currents are affecting coral colonization off the harbor 

mouth. 

• Define boundaries of the degraded area off the harbor mouth 

to evaluate its stability, the processes affecting it, and/or 

to determine if the adjacent areas of thriving coral habitat 

are expanding, contracting, or susceptible to these same 

processes.

• Evaluate freshwater conduits and establish water-quality and 

benthic-habitat monitoring locations along the north boundary 

of the park, off Kohanaiki, near areas of recent and future 

development of housing and golf courses.

• Carry out additional scuba transects to better quantify spatial 

variations in the percent cover, health of P. compressa, and 

structure of the shelf-escarpment habitat.

• Establish long-term coral and fish monitoring sites to monitor 

coral health and ecosystem health throughout the park.

• Collect airborne infrared or hyperspectral imagery to isolate 

spectrally unique bio-indicators to improve delineation of 

intertidal habitats.
Study Area 3

Introduction

This study is the result of a collaborative effort between 

the Coral Reef Project of the U.S. Geological Survey (USGS) 

Coastal and Marine Geology Program and Kaloko-Honokōhau 

National Historical Park (KAHO), the only national park 

along the west coast of the Island of Hawai`i to include a 

marine region within its official boundaries. The purpose of 

the study was to develop benthic-habitat classification maps 

for the marine lands within and adjacent to KAHO. Baseline 

maps and a Geographic Information System (GIS) database of 

biological and geological resources of these marine lands are 

provided in order to facilitate the management, interpretation, 

and understanding of park resources. 

Using a combination of aerial photography, bathymetry, 

video, and still imagery, a total area of nearly 2.5 km2 was 

mapped between Noio Point and Wawahiwa`a Point from the 

shoreline out to the west boundary of the park. The total area 

also includes two areas north and south of the park that were 

mapped from the shoreline to 40-m water depth (fig. 1). The 

interpreted geological and benthic-habitat classification maps 

and GIS database produced by this collaborative effort are 

included in conjunction with this report.

Marine resources located within KAHO include coral 

and coral reef habitat for many marine animals, including 

the green sea turtle and a variety of fish and invertebrates. 

In addition, many archeological, cultural, and recreational 

resources are located within the marine realm of the park. 

Special issues of concern for the park include establishing 

baseline conditions of the offshore resources before the 

planned harbor expansion near the south end of the park and 

a golf course/resort/residential development near the north 

boundary.

Study Area 

General Setting

Kaloko-Honokōhau National Historical Park (KAHO) 

is one of three National Park lands located along the west 

coast of the Island of Hawai`i. The park was established by an 

act of Congress (Public Law 95-625) in 1978. The legislated 

boundary of the park encloses approximately 1,160 acres, 

including nearly 600 acres of submerged marine resources. To 

date, only a portion of the park has been acquired by the NPS, 

with the remaining acreage held privately or by the state of 

Hawai`i. The submerged lands are currently managed by the 

State of Hawai`i, Department of Land and Natural Resources, 

Division of Aquatic Resources (DLNR-DAR). KAHO is one 

of only three National Park lands in Hawai`i to include marine 

resources within its official boundaries. 

KAHO is located adjacent to a moderately well 

developed area of the Kona coast. The park is bordered on 

the south by the Honokōhau small-boat harbor, which is the 

primary fueling, maintenance, and berthing facility on the 

central Kona coast. The harbor was quarried out of basalt 

rock from the shoreline landward more than 0.5 km. The first 

phase of construction was completed in 1970, and secondary 

expansion was completed in 1979. A county landfill and 

wastewater-treatment facility that discharges treated effluent 

are located less than 2 km upslope of the harbor and the 

park. Across the highway from the east boundary are a rock 

quarry and light industrial and business district. Construction 

of a golf course and a resort/residential development with 

500 single-family housing units, The Shores of Kohanaiki, 

began in 2005 on lands along the north boundary of the park 

within the Kohanaiki ahupua`a (a traditional Hawaiian land 

division extending from the upper ridgeline slopes to the sea). 

Development slated (circa 2006) for the lands adjacent to the 

park in the south include a 300-percent expansion of the smallboat harbor along with construction of hotels, condominiums, 

and a light industrial park (fig. 2). 

The upland area of the park is composed of three 

Holocene basalt flows that originated from Hualālai Volcano. 

Flat to gently rolling pahoehoe and rough jagged a`a types of 

basalt flows are both found within the park and range in age 

from 10 ka (thousand years) to 1.5 ka (Wolfe and Morris 1996; 

fig. 3). Together they form a gentle seaward-sloping surface 

that meets the shoreline along a mostly flat-lying, narrow 

intertidal zone, except south of the harbor, where the shoreline 

is marked by a cliff 2-3 m high. A geological resources 

evaluation, including an overview of the regional geology, 

local volcanic deposits, and a detailed description of coastal 

landforms in the upland portion of the park can be found in a 

companion paper by Richmond and others (2007). 

The offshore region of KAHO is characterized by 

multiple coalescing basalt flows, as discussed in detail below. 

The geologic mapping of Wolfe and Morris (1996) ends at the 

shoreline, and thus the geologic ages of the submerged flows 

are unknown and the relative relations to the emergent flows 

poorly constrained. 

The mean tidal range at Kailua-Kona, which is a subordinate 

tidal station adjusted to the primary station at Hilo, is 1.4 feet 

(0.43 m) with a spring range of 2.1 feet (0.64 m) and a mean tide 

level of 0.9 feet (0.27 m) relative to mean lower low water (mllw) 

(National Oceanic and Atmospheric Administration National 

Ocean Service, 2005).

The numerous cultural and natural resources within the 

park include archeological sites, petroglyphs, native species, 

anchialine pools (inland depressions connected to the ocean by 

subterranean conduits), and three ancient manmade fishponds 

(Kaloko, `Aimakapā, and `Ai`ōpio fishtrap). In addition to 

these historical and natural resources within the upland part of 

the park, the offshore component of KAHO hosts a rich coralreef community, habitat for many diverse marine species, as 

well as submerged archeological sites and popular recreational 

resources. 

Potential threats and stressors to the modern marine 

environment include ground-water and surface-water 

contamination, invasive plants and algae, fishing pressure and 
4 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Kaloko-Honok–ohau

National Historical Park

Queen Ka`ahumanu Highway

Wawahiwa`a

Point

Kaiwi

Point

Kaloko Point

Noio

Point

Maliu

Point

Kaloko

Fishpond

`Aimakapä

Fishpond

Honoköhau

Harbor

Honoköhau

Bay

`Ai`öpio Fishtrap

Alula Bay

Legislated park boundary

Actual park boundary

Mapped area

Pacific

Ocean

Hawaiian Islands

MAP Hawaii

AREA

20° N 

19°30'

19°

156° W 155°30' 155°

Kilometers

0 50

Kaloko-Honoko–hau

National Historical Park

(KAHO) Hilo

Kailua-Kona

Mauna Loa

Mauna Kea

Huala

–lai

Kohala

19°42' N 

19°41'

19°40'

156°3' W 156°2' 156°1'

0 1

Kilometers

Figure 1. Location map showing the boundaries of Kaloko-Honoko–hau National Historical Park, the mapped area, 

and the geographic locations described in this report. The “legislated boundary” was established by the U.S. 

Congress in 1978. The “actual boundary” includes only lands actually acquired by the National Park Service.
Study Area 5

use of monofilament gill nets (which can ensnare marine life 

or become tangled on reefs and then be left behind as fishing 

debris), and visitor use impacts, such as scuba diving and 

snorkeling. Illegal dumping, oil releases, boat groundings, 

and other physical damage to reef resources are potential 

threats from users of the nearby harbor. The proximity of 

coastal developments and their effects on water quality 

and aquatic ecosystems are also important considerations 

(DeVerse, 2006; Hoover and Gold, 2005). 

Wave Climate

Although typically considered a low wave-energy coast, 

the Kona coast can experience large wave events associated 

with seasonally varying wave sources. Moberly and Chamberlain (1964) describe four primary wave patterns that influence 

the main eight Hawaiian Islands, including the following:

North Pacific swell.—This generates some of the largest 

waves in the Hawaiian Islands. It is produced by storms in the 

Aleutians and mid-latitude lows and approaches from the NW 

to NE. The largest waves are from October to May, and have 

heights of 8–14 ft (2–5 m) and periods of 10–15 s.

Northeast trade waves.—The second most powerful or 

influential waves on the islands are generated by trade winds 

that blow across the open ocean. These approach from the N to 

SE. The largest waves are from April to November, and have 

heights of 4–12 ft (1–4 m) and periods of 5–8 s.

Kona storm waves.—These waves are very erratic and 

infrequent. They are generated by local fronts or extratropical 

lows and are associated with the weakening of the trade winds. 

They approach from SE to SW. The largest waves are from 

SW, usually in the winter time (December-March), and have 

heights of 10–15 ft (3–5 m) and periods of 8–10 s.

Southern swell.—These waves are generated by winter 

storms in the Southern Ocean. The largest waves are from 

April to October. They are more common than Kona storms 

Kaloko-Honok–ohau

National Historical Park

Proposed commercial development

Planned harbor expansion

Developer owned

Luxury homes and golf course 

 under construction

Existing industrial development

Planned industrial development

Legislated park boundary

Actual park boundary

Highway

N

Kilometers

0 1

Figure 2. Map showing land use around Kaloko-Honoko–hau NHP circa 2006 (from unpublished 

National Park Service data; Sallie Beavers, written commun., 2006).
6 Kaloko-Honok–

ohau National Historical Park, Hawai`i

3,000–5,000

3,000–5,000

3,000–5,000

1,500–3,000

1,500–3,000

5,000–10,000

5,000–10,000

1,500–3,000

3,000–5,000

5,000–10,000

KAHO park boundary

Age of flow, in years B.P.

19°41' N

19°40'

156°2' W 156°1'

Kilometers

0 1

Figure 3. Aerial photomosaic showing volcanic flows within Kaloko-Honoko–hau NHP. Three distinct 

flows, aged between 1,500 and 10,000 years, all originated from the Hualalai Volcano (Wolfe and 

Morris, 1996). The offshore part of the figure is Quickbird satellite imagery draped over bathymetry. 
Previous Efforts 7

waves, but smaller, having heights of 1–4 ft (0.3 to 1.3 m) and 

periods of 14–22 s.

 The Kona coast is protected from the effects of northeast 

trade waves by its location along the west coast of the island. 

It is also semiprotected by the islands of Maui, Moloka`i, and 

Lāna`i from all but the most westerly of north Pacific swell. 

Hence, primary wave energies that affect the Kona coast and 

KAHO in particular are from westerly north Pacific swell, 

southern swell, Kona storm waves, waves associated with the 

passage of low-pressure systems and typhoons (hurricanes), and 

locally generated wind waves (fig. 4). 

Previous Efforts

 Previous efforts to document or evaluate the underwater habitat and geological resources in Kaloko-Honokōhau 

NHP are limited. Recently, Hoover and Gold (2005) presented an extensive assessment of coastal water resources 

and watershed conditions in the park, which includes an 

overview of offshore resources and discussion of previous 

studies. Parrish and others (1990) provide a comprehensive 

description of the physical characteristics and biological 

communities of the intertidal and subtidal environments. 

Shoreline habitat, intertidal habitat, and nine major subtidal 

habitats are differentiated, including shallow sand, shallow 

pavement, shore cliff, shallow cliff, deep cliff, boulder and 

deep pavement, pinnacles and canyons, deep coral slope, and 

deep sand zones. Coral, fish, and invertebrate communities 

specifically associated with each of the habitat zones are 

also described in detail by Parrish and others (1990). 

The U.S. Army Corps of Engineers compiled and 

summarized the results of oceanographic, water-quality, 

and biological investigations conducted between 1971 

and 1982 after the initial construction and expansion of 

the Honokōhau Harbor (U.S. Army Corps of Engineers, 

1983). These studies included surveys of water quality and 

circulation and of the status and population of plankton, 

coral, invertebrates, and fish. In that compilation, Maragos 

(1983) describes the patterns of coral colonization within 

and outside of the harbor and entrance channel over the 

11-year period (1971–1982). Direct physical impact to 

existing corals was limited to the area just seaward of where 

the entrance channel was quarried and dredged from the 

existing shoreline. Surveys within the harbor and entrance 

channel showed relatively rapid coral colonization in the 

11 years following harbor construction. Observations also 

showed increased coral mortality and a decrease in individual species abundance following the harbor expansion in 

1979, although there was little evidence linking the decline 

to harbor construction (Maragos, 1983). Surveys conducted outside of the harbor entrance showed no substantial 

changes between 1971 and 1982, and flourishing coral communities in water depths less than 5 m appeared unaffected 

by the blasting and dredging of the entrance channel. 

A benthic habitat map for the KAHO area was produced in 2002 by National Oceanic and Atmospheric 

Administration (NOAA) Biogeography Team as part of a 

larger effort to map the distribution of coral reefs and other 

benthic habitats throughout the main Hawaiian Islands (fig. 

5). Using aerial photography collected in 2000, coral reefs 

and other benthic habitats were mapped using a minimum 

mapping unit of 1 acre and the classification scheme established by Coyne and others (2003). For more information 

see: http://ccma.nos.noaa.gov/products/biogeography/

hawaii_cd/.

Data and Methods

A standard for characterization of coral-reef environments was first implemented by NOAA for mapping the Florida Keys (Rohman and Monaco, 2005) and Puerto Rico and 

the Virgin Islands (Kendall and others, 2001). This standard 

for mapping coral reefs in the United States and its territories 

describes benthic habitats on the basis of their sea-floor geomorphology, geographic zonation, and biological cover.

In this study, the benthic-habitat classification maps 

were created using the standards established by NOAA but 

at a finer scale (minimum mapping unit of 100 m2 versus 1 

acre) and with additional data sources, including existing 

color aerial photography, Scanning Hydrographic Operational 

Airborne Lidar Survey (SHOALS) bathymetric data, georeferenced underwater video, and still photography. The maps 

Dec-Mar

Oct-May

Apr-Nov

Apr-Oct

45°

0°

282°

258°

210°

147°

123°

KONA STORM WAVES

SOUTHERN SWELL

NORTHEAST

TRADE WAVES

NORTH PACIFIC SWELL

KAHO

Hawai`i

Kaua`i

O`ahu

Moloka`i

Maui

La–na`i

Kaho`olawe

Figure 4. Diagram illustrating primary wave patterns for the main 

Hawaiian Islands (after Moberly and Chamberlain, 1964). 
8 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Artificial/fish ponds

Hardbottom/reef rubble

Hardbottom/uncolonized 

 volcanic rock/boulders

Land

Mud

Reef/aggregate coral

Reef/colonized volcanic 

 rock/boulders

Sand

Unknown

KAHO park boundary 

NOAA habitat classes

Descriptor

19°41' N

19°40'

156°2'30" W 156°2' 156°1'30"

Kilometers

0 1

Figure 5. Example from the KAHO area of the photography and benthic habitat maps produced and used by the 

National Oceanic and Atmospheric Administration’s (NOAA) Biogeography Program for the main eight Hawaiian 

Islands. Data from: http://ccma.nos.noaa.gov/products/biogeography/hawaii_cd/
Data and Methods 9

and infrared aerial photographs were collected in August and 

October 2002, respectively. The images were orthorectified, 

mosaicked, and geometrically registered to true map coordinates by the NPS, resulting in a digital mosaic with a resolution of 0.16 m per pixel (fig. 7). Metadata included with the 

data states that the horizontal accuracy of this photography is 

“better than 2 m.” In places, adjacent frames of imagery overlap and sea-floor features are obscured. Overall, the photography is quite good, with most features being recognizable to a 

water depth of 15 to 25 m. 

Pan-sharpened (an image processing method in which a 

higher resolution panchromatic image is merged with a lower-resolution color or multispectral image, resulting in a higher 

resolution image with as much of the spectral information as 

possible), multispectral Quickbird satellite imagery is used as 

a background image for many figures in this report because 

of its superior visual quality and larger coverage area (fig. 

8). Quickbird imagery was not used for interpretive purposes 

because of its lower spatial resolution of 0.6 m.

SHOALS Bathymetry

High-resolution SHOALS bathymetry point data collected in 2000 by the U.S. Army Corps of Engineers (USACE) 

were obtained and converted to a raster surface (fig. 9). The 

bathymetric data have an average horizontal point spacing 

of 4 m (± ~3 m) and a vertical resolution of ± 15 cm, with a 

maximum water penetration of about 42 m in the study area. 

The vertical datum is mean lower low water (mllw). The 

SHOALS technology determines water depth by comparing 

the time difference between a pulse of laser energy reflected 

off the surface of the water and one reflected off the sea floor. 

This time difference is difficult to resolve in shallow water (< 

~1 m) or where waves are breaking. The maximum depth the 

system is able to sense is related to the complex interaction of 

reflectance of bottom material, incident sun angle and intensity, and the type and quantity of particles in the water column. 

As a rule of thumb, the SHOALS system should be capable 

of sensing bottom to depths equal to two or three times the 

Secchi depth—the depth to which an 8-inch (20 cm) disk with 

alternating black and white quadrants can be seen from the 

surface. For further details regarding SHOALS data, see http://

shoals.sam.usace.army.mil. 

For the most part, continuous bathymetric data were 

obtained for the entire park area, except in the shallow coastal 

waters of Honokōhau and Kaloko Bays and a swath of missing 

data in the central part of Honokōhau Bay (fig. 9). Bathymetry in the central part of Honokōhau Bay was filled using 

the few data points available from the historical National 

Ocean Service (NOS) survey H09336, collected in 1968. A 

triangulated irregular network (TIN) of the point data was 

generated, from which one- and four-meter grids were created. 

One-meter grids were used for visualization purposes only, but 

the four-meter grids were used for all analytical calculations 

and interpretations. Isobaths, hillshades, and slope maps were 

were generated using both ArcView and ArcMap Geographic 

Information System (GIS) software by ESRI (http://www.

esri.com) and a statistical analysis of accuracy of the resultant 

maps was performed. The flowchart in figure 6 illustrates the 

complete methodology. 

Background Data

Aerial Photography

The National Park Service (NPS) provided the aerial 

imagery used as a base layer in this mapping effort. True-color 

Interpretation

using ArcGIS 8.3

ArcView 3.2a

and Habitat Digitizing

extension

Draft Map

Final map and

written report

Accuracy

assessment

and

matrix calculated

Mapped

polygon

correct?

Make corrections to

mapped polygons

YES

NO

Video tows

SCUBA surveys

Snorkel surveys

SHOALS bathymetry

Aerial Photography

Base layers

and

in situ observations

NOAA random points

Field check

 observations

USGS random points

Figure 6. Flowchart illustrating methodology used to create the 

habitat map. See text for complete description. 
10 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Mapped area

SHOALS bathymetry

Limit of photo interpretation

KAHO park boundary

19°41' N

19°40'

156°2'30" W 156°2' 156°1'30"

Kilometers

0 1

Figure 7. Aerial photomosaic showing the mapped area, the coverage area of SHOALS bathymetry, the offshore 

limit of interpretable aerial photography, and the KAHO park boundary. 
Data and Methods 11

derived from these grids using standard ArcMap functions and 

then used to assist in the interpretation.

Additional reconnaissance-type bathymetry data were 

collected using a ship-mounted Lowrance fathometer to obtain 

general information on water depth and sea-floor morphology 

beyond the limit of the lidar data. No corrections for variations 

in water temperature or salinity with depth were applied to 

the data. Because of this, comparisons between the lidar and 

fathometer-derived depths for the same area show greater 

offsets with increasing water depth. Geographic positioning 

was obtained using a Garmin GPS76 receiver enabled with a 

Wide Area Augmentation System (WAAS). The stated horizontal accuracy of the Garmin GSP76 is better than 3 m when 

receiving WAAS corrections. The fathometer’s transducer was 

located approximately 5 m aft of the GPS antenna. This offset 

was applied when comparing the data sets.

Acquired Data

Underwater Video and Still Photography

Nearly 48 trackline kilometers (22 hours) of underwater video footage and more than 500 still images (89 towed 

lines, 124 on-station drop/drift sites, 5 SCUBA, transects 

and 3 snorkle transects), were collected during three field 

surveys between December 2003 and August 2004 (fig. 10). 

Navigation and other information regarding these surveys are 

available online at: 

http://walrus.wr.usgs.gov/infobank/a/a803hw/html/a-8-

03-hw.nav.html

http://walrus.wr.usgs.gov/infobank/a/a204hw/html/a-2-

04-hw.nav.html

http://walrus.wr.usgs.gov/infobank/a/a604hw/html/a-6-

04-hw.nav.html

Aerial Photography Quickbird Satellite Imagery

KAHO park boundary

19°41'

19°41' N

19°40'

156°2'30" W 156°2' 156°1'30" 156°2'30" 156°2' 156°1'30"

Figure 8. Comparison of aerial photomosaic (left) and Quickbird satellite imagery (right) of the KAHO park area.
12 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Several types of camera systems and collection methods 

were used. During diving and snorkeling, video was collected 

with a hand-held SONY TRV-900 video recorder and still 

images were obtained using a hand-held digital camera (Olympus C-4000, Sony DCS-P5, or Canon PowerShot S-400). 

Video imagery was primarily obtained by either towing a 

camera behind a vessel while underway or dropping it over the 

side while remaining on a fixed station or drifting slowly. Two 

vessels were used during the study, the Alyce C, a 32-ft vessel 

operated by Captain Joe Reich of Moloka`i (fig. 11) and a 13-ft 

Boston Whaler owned by the NPS. The camera system used 

was a watertight video camera illuminated with a light-emitting 

diode (LED) light ring designed by SeaViewer Underwater 

Video Systems (http://www.seaviewer.com). When rigged for 

towing, the camera was mounted in a small aluminum handheld frame with a rear-mounted plastic fin (fig. 12A). When 

rigged for on-station dropping, the SeaViewer camera and light 

were integrated with two battery-powered lasers and a Seabird 

CTD instrument in a steel frame (fig. 12B). Live video from 

both systems was viewed in a shipboard laboratory on a standard CRT monitor and recorded directly to miniDV tape (fig. 

13). Time, date, location, and ship speed were overlaid on the 

video using Sea-Trak Global Positioning System (GPS) Video 

Overlay, also developed by the SeaViewer Company.

Simultaneous navigation, recording of ship position, and 

feature annotation were conducted in real time using Red Hen 

Systems (http://www.redhensystems.com) VMS200 hardware 

and MediaMapper software on a PC laptop. Location data were 

recorded using a hand-held, WAAS-enabled, Garmin GPS76 

receiver. The VMS200 transmitted NMEA-formatted GPS data 

at two-second intervals to the first audio channel of the video 

tape. A database was simultaneously created by MediaMapper 

to cross-reference the GPS locations and video time codes. This 

technique allowed for navigation and video to be viewed in real 

time and the location of features of interest and comments (for 

example, start/end of lines, substrate types) to be added to the 

database during data collection. Back in the lab, this technique 

allowed rapid random access to the original video by selecting 

locations along the navigation trackline within MediaMapper 

and GeoVideo (an extension developed by Red Hen Systems 

for integration with the ESRI ArcMap platform) software packages. Video could be interactively queried and geographically 

referenced feature annotations added to the database.

Kilometers

Contour interval 5 meters

0 1

11

0 MLLW

SHOALS bathymetry,

in meters

42

Kilometers

Contour interval 5 meters

0 1

11

0 MLLW

SHOALS + NOS

bathymetry, in meters

42

19°41'N

19°40'

156°2'30" W 156°2' 156°1'30" 156°2'30" 156°2' 156°1'30"

Figure 9. Aerial photomosaics of the KAHO park area overlain with bathymetry data. Left image: Gridded data set showing original 

SHOALS survey coverage. Right image: Gridded data set with the gaps filled using soundings from an historical National Ocean 

Service (NOS) bathymetric survey.
Data and Methods 13

KAHO tows

KAHO drops

KAHO snorkle

KAHO scuba

KAHO park boundary

Video tracklines

19°41' N

19°40'

156°2'30” W 156°2' 156°1'30"

Kilometers

0 1

Figure 10. Aerial photomosaic of the KAHO park area overlain with video trackline locations.
14 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Video Mosaics

Recent advances in software development have allowed 

digital video to be converted to georeferenced image strips 

that can be imported into a GIS. Researchers at the University 

of New Hampshire (UNH) are developing software tools for 

pattern recognition from one video frame to the next, which 

results in a continuous image mosaic made from overlapping 

video frames. Collaborators from the USGS (Pete Dartnell) 

and UNH (Yuri Rzhanov) used sea-floor video acquired during 

this study to make 38 mosaics of the study area. Original video 

on miniDV tape was converted into Audio Video Interleave 

(AVI) format using commercial software and divided into 

2-minute sections in order to limit file size and to minimize 

propagation errors. Using the suite of UNH’s software, the 

video was then de-sampled, keeping every 15th to 20th frame 

(depending on camera sled speed), and the outer edges of the 

AVI were cropped to remove the navigation and time stamps 

(Sea-Trak) superimposed on the video. With the clean AVI, 

both automatic and manual pattern recognition were performed, calculating the X-Y shift and rotation from one frame 

to the next. An image mosaic was generated using the video 

frames and the offset information. Finally, the image mosaics were rectified using GIS techniques and the navigation 

information on the original video, as well as true-color aerial 

photography where shallow portions of the reef were visible. 

Once the imagery was properly georeferenced, it was imported 

into a GIS for direct comparison and ground-truthing of the 

benthic habitats (fig. 14).

Benthic Habitat Mapping Using GIS

Digital benthic habitat maps were created using ESRI’s 

ArcMap 8.3 and ArcView 3.2 software with a habitat digitizing 

extension created by NOAA (to download the extension see: 

http://ccma.nos.noaa.gov/products/biogeography/digitizer/. 

Figure 11. Photograph of the Alyce C of Moloka`i heading out of 

Ma–`alaea Harbor, Maui. 

Figure 12. Photograph of the SEAVIEWER camera system (A) rigged 

to collect towed video, and (B) with SeaBird CTD acquisition system 

rigged to collect drop video and CTD information. 

Figure 13. Photograph of shipboard laboratory set-up for 

navigation, recording of ship’s position, and feature annotation. 
Data and Methods 15

The habitat digitizing extension allows users to delineate 

habitat areas and assign attributes to the habitat polygons 

based on a predetermined classification scheme using a pointand-click menu system.

We digitally delineated and classified 1,185 polygons, 

covering nearly 2.5 km2. A minimum mapping unit (MMU) 

of 100 m2 was used; however, smaller features were mapped 

if they carried habitat significance (for example, an individual 

coral colony 2 m in diameter located in an otherwise uncolonized area).

Features were primarily interpreted and digitized using 

aerial photography. In areas where sea-floor features were too 

deep to be resolved in the aerial photograph (about 25 m or 

greater water depth), the morphological characteristics of the 

sea floor observed in the bathymetry, combined with underwater imagery, were used to define and classify the habitat 

polygons. 

Classification Scheme

The classification scheme used was based on a scheme 

established by NOAA’s biogeography program in 2002 

(Coyne and others, 2003) for the main eight Hawaiian Islands 

and subsequently revised in 2004 (National Oceanic and 

Atmospheric Administration National Centers for Coastal 

Ocean Science, 2005). Developed with input from coral reef 

scientists, managers, local experts, and others, the hierarchal scheme allows users to expand or collapse the level of 

thematic detail as necessary. We used the NOAA definition 

of benthic habitats and classification scheme as a starting 

point to provide continuity with other habitat maps. We made 

modifications to the classification scheme where necessary to 

improve identification of benthic habitats and geologic substrates within Kaloko-Honokōhau NHP.

The identification of coralline and turf algae from towed 

video was nearly impossible, and no attempt was made to 

map these cover classes for this study. However, turf and/or 

calcareous coralline algae, readily identifiable when diving 

and snorkeling, are likely the dominant cover classes in areas 

classified as “uncolonized” (Rodgers and others, 2004). 

The classification scheme uses five basic attributes to 

describe each polygon on the benthic habitat map: (1) the 

major structure or underlying substrate, (2) the dominant 

structure, (3) the major biologic cover found on the substrate, 

(4) the percentage of major biological cover, and (5) the geographic zone indicating the location of the habitat. The structure combination with the overlying biologic cover is referred 

to as a “habitat.” Majority rules—if a polygon includes two 

or more substrate or coverage types, the polygon is identified 

with the dominant one. 

The four major structure (substrate) types are further 

subdivided into fifteen dominant structures (table 1). Ten 

major biologic cover types are also modified by the percent 

of coverage (tables 2 and 3). The classification scheme allows 

for any biologic cover to be found on any structure/substrate, 

although many combinations are unlikely (for example, coral 

on sand, or emergent vegetation on spur-and-groove). Less 

than 10 percent cover of any type is equivalent to 90–100 

percent uncolonized; therefore 0–10 percent cover is not used. 

Each polygon is coded with a 4-digit UNIQUEID attribute that 

reflects the combination of the individual habitat components 

(major structure, dominant structure, major biologic cover, and 

percent cover).

Table 1. Major structure (substrate) types with dominant 

structure subdivisions.

[Numbers represent UNIQUEID identifier.]

Major Structure Dominant Structure

1 Unconsolidated 

Sediment

1 Mud

2 Sand

2 Reef and 

Hardbottom

1 Aggregate Reef

2 Spur-and-Groove

3 Individual Patch Reef

4 Aggregated Patch Reef

5 Volcanic Pavement with 10–50% Rocks/

Boulders

6 Volcanic Pavement

7 Volcanic Pavement with >50% Rocks/

Boulders

8 Volcanic Pavement with Sand Channels

9 Reef Rubble

3 Other 0 Unknown

1 Land

2 Artificial

3 Artificial/Historical

9 Unknown 0 Unknown

Figure 14. Example from KAHO park of an underwater video 

mosaic overlaid on aerial photography. 
16 Kaloko-Honok–

ohau National Historical Park, Hawai`i

The fifth attribute, zone, refers only to a habitat community’s location within the coral reef ecosystem and does 

not indicate the substrate or biological cover type (fig. 15). 

Eleven zones correspond to typical reef geomorphology found 

in current literature (table 4). An additional dredged zone has 

been added to include those areas where anthropogenic change 

has occurred (for example, harbors and manmade channels). 

Detailed descriptions of habitats and zones, including example 

photographs, may be found in the appendix.

Accuracy Assessment

The validity, or usefulness, of any classification or interpretation may be determined with an accuracy assessment, 

which compares the interpretation with what is actually found 

in the field. In this project, the benthic habitat map’s overall 

accuracy and its accuracy from both the user and producer 

points of view were determined. 

Overall accuracy indicates which points on the map 

are classified correctly according to a field check (Lillesand 

and Keifer, 1994). Producer accuracy indicates how well the 

map producer classified the different cover types (that is, the 

number of points on the map labeled correctly). User accuracy 

indicates the probability that a point in a given class is actually 

represented by that class in the field (that is, which mapped 

areas are actually what the map says they are).

For this study, 187 randomly generated sample points 

were visited by third-party coral reef research biologists from 

the University of Hawai`i who are highly familiar with the 

classification scheme. Once the accuracy assessment calculations were completed, any misinterpreted polygons identified 

were corrected, thus increasing the percent accuracy of the 

final map.

Data Archive

Underwater video footage, photographs, and associated 

shapefiles have been transferred to DVD. One complete set 

will be held in the USGS archives (http://walrus.wr.usgs.gov/

infobank/), and the other will reside at the National Park Service, Kaloko-Honokōhau NHP Headquarters. This report and 

project shapefiles are also available online at http://pubs.usgs.

gov/sir/2006/5256.

Results

Benthic Species

Colleagues from the University of Hawai`i Coral Reef 

Assessment and Monitoring Program (CRAMP) conducted 

a Rapid Assessment Transect (RAT) survey to quantify and 

evaluate the distribution of coral, invertebrates, algae, and 

fish within the park (Rodgers and others, 2004). Seventeen 

random sites were visited, and detailed biological characteristics, including percent coral cover, species richness and 

diversity, algal functional groups (macroalgae, coralline, and 

turf), substrate cover, and topographic relief (rugosity) were 

quantified along a 10-m transect at each site. Invertebrate and 

fish populations were quantified at the same sites along 25-m 

Table 2. Major biologic 

cover classes.

[Numbers represent UNIQUEID 

identifier.]

Major Biological Cover

0 Unknown

1 Uncolonized

2 Macroalgae

3 Seagrass

4 Coralline Algae

5 Coral

6 Turf

7 Emergent Vegetation

8 Mangrove

9 Octocoral

Table 3. Percent 

cover classes

[Numbers represent 

UNIQUEID identifier.]

Percent Cover

0 Unknown

2 10 –<50%

3 50 –<90%

4 90 –100%

Table 4. Geomorphic zones 

of coral reef ecosystems.

Zone

Land

Shoreline/Intertidal

Vertical Wall

Lagoon

Back Reef (with Lagoon)

Reef Flat (without Lagoon)

Reef Crest

Fore Reef

Bank/Shelf

Bank/Shelf Escarpment

Channel

Dredged

Mean high tide line

Spring low tide line

Shoreline/

Intertidal

Reef flat Reef

crest Fore reef

Shelf

Shelf

escarpment

Figure 15. Schematic diagram showing the generalized cross-shelf 

coral reef zonation. Not shown: land, channel, dredged, or vertical 

wall (modified from Kendall and others, 2004). Detailed descriptions 

of the zones are given in the appendix.
Results 17

transects. Their analysis shows that the substrate in the park 

is dominated by turf algae and calcareous coralline algae. 

Very low amounts of macroalgae and sand were identified. A 

total of nine species of coral from five genera were quantified 

along the transect lines (fig. 16). Absolute coral cover ranged 

from less than 3 percent to more than 50 percent and mean 

coral cover was 23 percent, similar to the statewide average 

of 22 percent. The reefs at KAHO are primarily Porites reefs, 

comprising mainly P. compressa and P. lobata; overall, four 

individual Porites species were identified. KAHO also has a 

high abundance of the endemic octocoral, Anthelia edmonsoni, with extremely high cover on some transects. This 

species is common at many other locations on the west coast 

of the Island of Hawai`i, although relatively rare at most other 

sites within the State. Seven species of invertebrates were 

observed within the park, most commonly the collector urchin 

Tripneustes gratilla and the rock-boring urchin Echinometra 

mathaei. The Crown of Thorns sea star, Acanthaster planci, 

was also observed at numerous locations within the park 

(table 5).

Benthic Habitats

Benthic habitat varies greatly throughout the study area 

(figs. 17, 18). Nearly 1.8 km 2 (73 percent) of the study area 

consists of a hardbottom structure that is potentially available for coral habitation; the remaining 27 percent includes 

unconsolidated sediment and artificial and artificial/historical 

features. Of the available hardbottom, 1.3 km2 (76 percent) 

is covered with a minimum of 10 percent coral. Coral cover 

is predominantly low, with 84 percent of the total hardbottom area covered with 10 to <50 percent coral. Significant 

areas of moderately high (50 to <90 percent; 14 percent total 

hardbottom) and high (90 to 100 percent; 2 percent total 

hardbottom) coral coverage are also mapped within the study 

area (fig. 19). Generally, coral cover increases with depth, 

and reaches maximum values between about 10 and 20 m of 

water (fig. 20).

Geologic Framework and Habitat Zones

The region offshore KAHO consists of multiple, coalescing volcanic flows that form distinct morphological regions 

and support diverse benthic habitats. The offshore geology 

is predominantly composed of smooth to undulating pahoehoe-type basalt flows that form flat to gently sloping benches, 

cliffs, and steep shelf escarpments (fig. 21). In some locations 

the basalt surface is irregular and mounded into ridges, pinnacles, and arches. Large rounded boulders and smaller scattered 

rocks are common throughout the marine portions of the park. 

In only a few locations does coral cover or accreted carbonate 

reef obscure the underlying volcanic surface. 

The underlying geologic framework and morphology 

of the submerged volcanic flows within Kaloko-Honokōhau 

NHP provide the primary control on benthic habitats within 

the park. Twelve unique habitat zones, based primarily on 

water depth, sea-floor slope, and seafloor structure describe 

the offshore morphology and typical coral communities 

found within the park. The habitat zones include shoreline/

intertidal, dredged, shallow cliff, shallow bench (narrow and 

broad), intermediate bench, deep bench, shelf break, shelf 

escarpment, pinnacles/ridges, deep cliff, and deep slope (fig 

22; table 6).

Table 5. Species observed at Kaloko-Honoko–hau National 

Historical Park (KAHO) during Rapid Assessment Transect (RAT) 

surveys (Rodgers and others, 2004).

Coral Invertebrates Algae

Anthelia edmonsoni1 Acanthaster planci Asparagopsis taxiformis

Cycloceris spp.2 Culcita novaeguinea Malamansia glomerata

Cyphastrea ocelina Diadema spp. Neomeris annulata

Leptastrea purpurea Echinothrix spp.

Montipora capitata Echinometra mathaei

Montipora patula Heterocentrotus mammilatus

Palythoa turberculosa1

Tripneustes gratilla

Pavona varians2

Pocillopora edouxii2

Pocillopora meandrina

Porites brighami

Porites compressa

Porites evermanni

Porites lichen2

Porites lobata

1

Soft corals; 2Species observed in the area, but not quantified along the 

transect line.

0

10

20

30

40

Cyphastrea ocellinaLeptastrea purpureaMontipora capitataMontipora patula

Pocillopora meandrinaPorites brighamiPorites compressaPorites evermanni

Porites lobata

Maximum percentage

Figure 16. The maximum percentage of the nine coral species 

quantified from all Rapid Assessment Transect (RAT) surveys (data 

from Rodgers and others, 2004). 
18 Kaloko-Honok–

ohau National Historical Park, Hawai`i

19°41' N

19°40'

156°3' W 156°2'

Kilometers

0 1

KAHO park boundary

Isobath, interval 5 meters

Benthic habitat classes

Wawahiwa`a Point

Kaloko Fishpond

Kaloko Point

`Aimakapä

Fishpond

Noio Point

Alula Bay

Maliu 

Point

Wawahiwa`a Point

Kaloko Fishpond

Kaloko Point

`Aimakapä

Fishpond

Noio Point

Alula Bay

Maliu 

Point

Sand, uncolonized

Aggregate reef, 50–<90% coral

Aggregate Reef, 90–100% coral

Volcanic pavement w/10–50% rocks/boulders, uncolonized

Volcanic pavement w/10–50% rocks/boulders, 10–<50% coral

Volcanic pavement w/10–50% rocks/boulders, 50–<90% coral

Volcanic pavement, uncolonized

Volcanic pavement,10–<50% coral

Volcanic pavement, 50–<90% coral

Volcanic pavement, 90–100% coral

Volcanic pavement, 50–<90% octocoral

Volcanic pavement w/>50% rocks/boulders,uncolonized 

Volcanic pavement w/>50% rocks/boulders, 10–<50% coral

Volcanic pavement w/>50% rocks/boulders, 50–<90% coral

Volcanic pavement w/sand channels, 10–<50% coral

Volcanic pavement w/sand channels, 50–<90% coral 

Volcanic pavement w/sand channels, 90–100% coral

Reef rubble, uncolonized

Reef rubble, 10–<50% coral

Reef rubble, 50–<90% coral

Other, artificial/historical

No bathymetric data

5

5

Figure 17. Benthic habitat map of Kaloko-Honoko–hau area draped on shaded relief bathymetry. Hatched lines indicate 

areas lacking bathymetric data. Background image is Quickbird satellite imagery.
Results 19

19°41' N

19°40'

156°3' W 156°2'

KAHO park boundary

Isobath, interval 5 meters

Percent coral cover

Wawahiwa`a Point

Kaloko Fishpond

Kaloko Point

`Aimakapä

Fishpond

Noio Point

Alula Bay

Maliu 

Point

Wawahiwa`a Point

Kaloko Fishpond

Kaloko Point

`Aimakapä

Fishpond

Noio Point

Alula Bay

Maliu 

Point

Uncolonized, sand

Uncolonized, hardbottom

Coral 10–<50%

Coral 50–<90%

Coral 90–100%

Octocoral 50–<90%

Unclassified

No bathymetric data 5

5

Kilometers

0 1

Figure 18. Map showing the distribution of percent coral-cover classes in the KAHO area draped on shaded relief 

bathymetry. Hatched lines indicate areas lacking bathymetric data. Background image is Quickbird satellite imagery.
20 Kaloko-Honok–

ohau National Historical Park, Hawai`i

C. Major biological cover on coral reef and hardbotttom

Area (m2)

Uncolonized

289,560

16%

Coral

1,354,156

76%

 Octocoral

 147,839

8%

10–<50% Coral

 1,135,510

84%

50–<90% Coral

191,057

14%

D. Percent hard coral cover on available hardbottom

Area (m2) 

90-100% Coral

 27,590

2%

V Pave 

w/10-50%

Rcks/Bldrs

370,735

15% 

V Pave w/>50% 

Rcks/Bldrs 

331,910 

13%

Volcanic pavement

 w/sand channels

28,883

1%

Artificial/historical

9,028 Aggregate reef

3,436

0%

Reef rubble

7,647

0%

1,048,944

678,971

B. Dominant structure/substrate

Area (m2) 

Volcanic pavement

43%

Sand

27%

0%

A. Major structure/substrate

Area (m2)

Other 

9,028

0%

Unconsolidated

sediment

678,971

27%

Coral reef and 

hardbottom

1,791,555

73%

0 20 40 60 80 100

Percent coral on available hardbottom

0

5

10

15

20

25

30

35

40

Depth

contour,

in meters

Uncolonized

10–<90%

50–<90%

90–<100%

Figure 19. Relative abundance of (A) major and (B) dominant substrate structures, (C) major biological coverage on coral 

reef and hardbottom, and (D) percent hard coral cover on available hardbottom in the KAHO study area. All unconsolidated 

sediment (27 percent of the study area) is sand (A, B). The remaining 73 percent of the study area is reef and hardbottom 

available for coral habitat (C). Of this available hardbottom, 76 percent is covered with a minimum of 10 percent coral (C, 

D). The majority of the study area is colonized with less than 50 percent live coral. Octocoral is considered separately from 

hard scleractinian coral. V pave = volcanic pavement; Rcks/Bldrs = rocks and boulders; Chnls = channels.

Figure 20. Bar graph showing the percent coral cover 

by depth. The highest coral cover is located in water 

depths between 10 and 20 m (33 and 66 ft).
Results 21

19°41' N

19°40'

156°2'30" W 156°2' 156°1'30"

KAHO park boundary

Sea-floor slope, in degrees

Wawahiwa`a Point

Kaloko Fishpond

Kaloko Point

`Aimakapä

Fishpond

Noio Point

Alula Bay

Maliu 

Point

Wawahiwa`a Point

Kaloko Fishpond

Kaloko Point

`Aimakapä

Fishpond

Noio Point

Honoko–hau

Harbor

Honoko–hau

Harbor

Alula Bay

Maliu 

Point

0–5

5–10

10–20

20–30

30–70

Vertical cliffs

Pinnacles/ridges/arches

Escarpment

Benches

Kilometers

0 1

Figure 21. Sea-floor slope map illustrating the complexity of the sea-floor surface and the variety of sea-floor 

structures within KAHO.
22 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Figure 22. Delineation of the twelve habitat zones described in the text, overlaid on shaded relief bathymetry. Hatched lines 

indicate areas lacking bathymetric data.

19°41' N

19°40'

Kilometers

0 1

156°2'30” W 156°2' 156°1”30” 

Wawahiwa`a Point

Kaloko Fishpond

Kaloko Point

`Aimakapä

Fishpond

Noio Point

Alula Bay

Maliu 

Point

Wawahiwa`a Point

Kaloko Fishpond

Kaloko Point

`Aimakapä

Fishpond

Noio Point

Honoko–hau

Harbor

–

Harbor

Alula Bay

Maliu 

Point

KAHO park boundary

Habitat zone

Shoreline/intertidal

Dredged

Shallow cliff

Shallow bench, narrow

Shallow bench, broad

Intermediate bench

Deep bench

Shelf break

Shelf escarpment

Pinnacles/ridges

Deep cliff

Deep slope

No bathymetric data
Results 23

Table 6. Total area and relative percentage of total

area of the twelve habitat zones.

Habitat zone Area

(m2

)

Total area 

(%)

Shallow cliff 7,047 0.3

Deep cliff 7,456 0.3

Dredged 11,144 0.4

Shelf break 37,134 1.5

Pinnacles/Ridges 78,109 3.1

Shoreline/Intertidal 78,431 3.2

Deep bench 83,365 3.4

Shelf escarpment 115,106 4.6

Shallow bench - narrow 157,640 6.4

Intermediate bench 512,431 20.7

Shallow bench - broad 635,722 25.7

Deep slope 751,290 30.4

Total 2,474,875

Shoreline/Intertidal

The shoreline/intertidal habitat zone is present throughout 

most of the study area but was difficult to differentiate from 

aerial photography alone. It was constrained by water depth 

(between about -1 and +1 m mllw), a wet/dry line, or deeper 

black color of the wet rocks as seen on the aerial photograph. 

This habitat is typically uncolonized pavement, scattered 

volcanic rocks (< ~ 0.5-m diameter), or sand. The pavement 

surface is commonly covered by a carpet of undifferentiated 

algae species. South of the harbor and west of Alula Bay the 

shoreline is delineated by a shear cliff that drops 2-3 m to the 

sea floor, and no significant intertidal habitat zone is present.

Dredged

The dredged habitat zone includes a small area off the mouth 

of the Honokōhau Harbor. Benthic cover includes poorly colonized pavement, rocks, boulders, and uncolonized sand. Coral 

cover is limited to isolated heads of P. meandrina and individual 

colonies of P. lobata. Some areas of higher coral cover were 

observed on the southern edge of the channel.

A

C D

B

Figure 23. Representative photos of the shallow bench habitat zone. A, Seaward edge of narrow bench characterized 

by scattered Pocillopora meandrina and Porites lobata on a volcanic pavement. B, A blanket of the lavender-colored 

octocoral Anthelia edmonsoni colonizing volcanic pavement in the shallowest regions of the broad bench. C, Lowlying ridges on the broad platform. D, P. meandrina and encrusting Porites species on smooth volcanic pavement that 

has been bored by urchins. 
24 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Shallow Bench (Narrow, Broad)

 A nearly flat, shallow bench habitat zone, extending 

seaward from the shoreline to water depths of at most ~6 m, 

exists throughout the study area. This habitat zone has been 

subdivided into two categories—narrow shallow bench and 

broad shallow bench. The narrow bench is typically less than 

50 m wide and commonly wave washed, whereas the broad 

bench extends several hundreds of meters offshore. 

The narrow shallow bench extends along the coast 

from Wawahiwa`a Point southward to about 400 m south 

of Kaloko Point and a ~400 m stretch south of Honokōhau 

Harbor. It is widest offshore of Kaloko Fishpond (~140 m), 

but in general is approximately 50 m wide. It is typically flat 

(slope < ~4°) and less than 5 m below sea level. It is commonly wave washed and fronted by a low cliff, 1-3 m high, 

along most of its reach. Substrate type and cover vary from 

uncolonized pavement and sand to poorly colonized pavement 

and boulders. Where present, coral cover is predominantly P. 

meandrina, with secondary P. lobata and low-lying encrusting 

coral species (fig. 23A). 

The broad shallow bench is the 2nd largest habitat zone in 

the study area. It begins about 325 m south of Kaloko Point 

and continues southward to just south of the Honokōhau 

Harbor. A small area of this zone is also present north of 

Wawahiwa`a Point. At its widest point, offshore of `Aimakapa 

Fishpond, the bench is nearly 700 m wide. It is a shallow (< 

~ 6 m), low-lying (avg slope < 3°) bench of pahoehoe-type 

volcanic pavement with many low ridges and troughs (< 1 

m high). Large waves commonly shoal and break across this 

shallow platform, especially over the northern section off 

`Aimakapā Fishpond. The breaking waves hindered validation of the benthic cover over the shallower portions of this 

habitat. Benthic cover includes uncolonized pavement near the 

shoreline and carpets of the lavender-colored octocoral Anthelia edmonsoni in water depths less than about 2 m (fig. 23B). 

Coral cover generally increases seaward. The flat volcanic 

pavement is poorly colonized, with scattered small colonies 

of primarily P. lobata (10 to <50 percent), although higher 

percentages of coral cover are found locally on the lee side 

of low-lying ridges and filling cracks in the volcanic surface 

(fig. 23C). Toward the seaward edge of the shallow platform, 

the volcanic surface is covered with scattered rocks (< 0.5 

m diameter) and colonization increases slightly (still <50 

percent), with larger colonies of P. lobata and P. meandrina. 

A

C D

B

Figure 24. Representative photos of the intermediate bench habitat zone. A, Poorly colonized, boulder-covered 

pavement at the base of the shallow cliff. B, Poorly colonized volcanic pavement with scattered rocks and rubble 

near the center of the study area. C, Porites species colonizing boulders south of Kaloko Fishpond. D, Moderately 

high coral cover on volcanic pavement offshore of Honoko–hau Harbor.
Results 25

The volcanic pavement in this area is also commonly bored by 

urchins (Echinometra mathaei; fig. 23D). The broad shallow 

bench is fronted by a shallow cliff 2-3 m high along its entire 

stretch, except south of the harbor and at several locations 

north of the harbor where no cliff is distinguishable from photography or bathymetry.

Shallow Cliff

The shallow cliff habitat zone fronts both the narrow 

and broad shallow benches. The cliff is a near-vertical wall, 

typically between 1 and 3 m high, although in places multiple 

steps separate the shallow bench from the intermediate bench 

below. The ~4-m point spacing of the lidar data is too coarse 

to accurately define the edges and morphology of the shallow 

cliff. In order to distinguish this near-vertical feature on a planar 

map, it was arbitrarily given a width of about 1 m in plan view. 

Where multiple steps could be identified, the seawardmost edge 

was mapped. This resulted in an overestimation of the relative 

surface area included in this habitat zone, although the total is 

still less than 1 percent of the total habitat mapped. The habitat 

was classified as uncolonized volcanic pavement, although 

limited areas of coral, both P. lobata and P. meandrina, were 

observed on the cliff faces and typically covered less than 10 

percent of the substrate.

Intermediate Bench

The intermediate bench habitat zone is the 3rd largest 

within the study area. Where the shallow cliff is present, the 

intermediate bench begins at its base and slopes gently (<12°) 

seaward to depths of around 20 m. South of the harbor, the zone 

directly abuts the 2-3-m-high cliff that marks the shoreline. 

The width of the bench varies between about 25 and 250 m but 

is typically about 75 m. It is narrowest in the northern part of 

the study area and widest off the harbor mouth. The seaward 

boundary of the habitat zone is generally the shelf break habitat 

zone, except in the northern part of Honokōhau Bay, where it 

abuts the pinnacles/ridges and deep bench habitat zones. 

The intermediate bench habitat zone claims the highest 

variety of dominant substrate structure, percent coral cover, 

and overall coral diversity among all the habitat zones within 

the park. The habitat zone includes all the habitat classes 

mapped except for uncolonized rocks and boulders, rubble, 

and octocoral on volcanic pavement. The majority of this 

habitat zone is characterized by poorly (10 to <50 percent) 

Figure 25. Representative photos of the shelf break and shelf escarpment habitat zones. A, Moderately high coral 

cover on shelf break. B, Poor coral cover on shelf break. C, Scattered coral and rubble on shelf escarpment. D, High 

coral cover and diversity on shelf escarpment. 
26 Kaloko-Honok–

ohau National Historical Park, Hawai`i

to moderately (50 to <90 percent) colonized rocks and 

boulders on volcanic pavement (fig. 24A-C). However, the 

highest coral cover, highest diversity, and the only area of 

vertically accreted carbonate reef in the study area are also 

located within this intermediate bench habitat in the southern 

part of Honokōhau Bay, just off the harbor mouth (fig. 24D). 

Off Kaloko Point, the normally smooth and flat-lying volcanic 

pavement characteristic of this habitat is more irregular, 

fractured, and undulating.

Shelf Break

The shelf break habitat zone marks the seaward boundary 

of the intermediate bench habitat zone and extends the length 

of the study area, except adjacent to the pinnacles/ridges and 

deep cliff habitat zones. The shelf break zone lies at depths of 

9 to 31 m and marks the transition between the gently sloping 

intermediate bench and the steep shelf escarpment below. Over 

most of the study area it is typically between 15 and 20 m 

deep; south of the harbor it is somewhat shallower, commonly 

between 12 and 15 m deep. Average slope values within this 

habitat zone are between 12° and 20°.

In general, the shelf break marks a dramatic transition 

in benthic habitat between the habitat zones above and below 

it. For example, fewer boulders and rocks exist on the shelf 

break compared to the intermediate bench, and coral cover 

is distinctly higher, and of higher diversity, compared to the 

shelf escarpment. A wide range of habitat classifications are 

included within this habitat zone (fig. 25A, B).

Shelf Escarpment

The shelf escarpment habitat zone extends the length of 

the study area except near the pinnacles/ridges and deep cliff 

habitat zones. The inner boundary of the shelf escarpment 

habitat zone is the seaward edge of the shelf break habitat 

zone in water depths of between about 15 and 20 m, and 

it continues to depths exceeding the limit of the lidar 

bathymetry data (>40 m). Limited fathometer transects show 

that the offshore slope flattens in water depths between 60 

and 75 m, marking the end of the shelf escarpment zone and 

the beginning of the deep slope (fig. 26). Slopes on the shelf 

escarpment typically range between about 20° and 45°.

The shelf escarpment is a habitat characterized by 

uncolonized to poorly (10 to <50 percent) colonized volcanic 

pavement that is essentially monotypic, patchy thickets of 

live and skeletal P. compressa and rubble (fig. 25C). The 

extreme slope causes this habitat to be highly unstable and 

vulnerable to damage from boulders, rocks, and larger coral 

heads tumbling down the slope, as well as damage from 

higher wave energy conditions associated with severe, but 

episodic, storms. Small rocks and rubble are common within 

this habitat, while large boulders are rare. In only a few areas 

does coral cover exceed 50 percent (fig. 25D). Near the shelf 

break and in areas where the slope is somewhat lower, P. 

lobata and P. meandrina also colonize this habitat. 

It was often difficult to distinguish live and dead coral 

percentages on P. compressa thickets using the towed video 

technique, especially in deeper water where natural light is 

diminished (fig. 27A). Commonly the habitat appeared to 

be continuous and in place rather than scattered rubble and 

broken fingers, although much appeared to be skeletal and 

not living. Drop-video and scuba transects often showed 

recent regrowth on the ends of the skeletal P. compressa

fingers (fig. 27B). The soft octocoral Anthelia edmonsoni was 

also commonly observed with the P. compressa framework. 

Our estimates from the video data are on the conservative 

side, resulting in a classification of low overall percentage 

of coral cover. Additional deep-water studies in this habitat 

are necessary to more definitively determine the health and 

vitality of this P. compressa habitat. 

Depth transitions were also difficult to determine because 

of the steep slope; a small distance over the surface of the 

water could correspond to a difference of several meters in 

water depth. Because of this, the depth of the transition from 

colonized to uncolonized coral is approximate. Where no other 

depth information was available, an arbitrary depth of 27 to 

30 m was used to delineate the transition from colonized to 

uncolonized pavement or rubble, based primarily on scuba 

transects and general studies of corals in the Hawaiian Islands 

(Grigg and Epp, 1989; Grossman and Fletcher, 2004).

Deep Bench

The deep bench habitat zone is located offshore of 

Kaloko Point. It extends as much as 250 m across the shelf 

between the intermediate bench habitat zone on the east and 

the deep cliff habitat zone on the west. It is bounded on the 

north by the pinnacles/ridges habitat zone and on the south by 

the intermediate bench and the shelf escarpment habitat zones. 

The deep bench habitat is a mostly smooth, pahoehoetype volcanic pavement with large areas of rubble and sand. 

It is slightly (1-3 m), but distinctly, lower than the adjacent 

intermediate bench and slopes gently seaward (~2°) across the 

shelf between about 12 and 22 m of water depth. It ends along 

the crenulated edge of the ~3-7-m-high, near-vertical deep 

cliff in ~18-22 m of water. The habitat supports a mostly low 

(10 to <50 percent) but variable coral cover of primarily small 

colonies of lobate P. lobata and P. meandrina, and includes 

patches of uncolonized pavement, sand, and rubble. Locally 

there are areas of higher coral cover with larger heads of P. 

lobata. A relatively large sand sheet abuts the intermediate 

bench along the south boundary of this habitat zone. 

Deep Cliff

The deep cliff habitat zone bounds the deep bench habitat 

zone along the seaward edge. It abuts the shelf escarpment 

habitat zone in the south and the seaward edge of the pinnacle/

ridges habitat zone in the north. The cliff is typically 3-7 m 

high, and its upper edge varies in water depth from about 18 
Results 27

Figure 26. Map of fathometer tracklines and selected profiles in the KAHO area showing variation in offshore 

morphology. Profiles show bathymetry measured using lidar data in pink and fathometer data in blue. Fathometer data 

show that the profile morphology in general flattens in water depths of about 60 to 75 m, although multiple benches and 

shelves may exist offshore. In many places, the maximum depth of the lidar bathymetric data is near the top of the shelf 

escarpment. White and yellow dashed lines show the top and base, respectively, of the shallowest shelf escarpment as 

inferred from the fathometer data. 

80

60

40

20

0

0100200300400500600700 -100

80

60

40

20

0

0100200300400500600700 -100

-80

-60

-40

-20

0

0100200300400500600700 -100

-80

-60

-40

-20

0

0100200300400500600700 -100

80

60

40

20

0

0100200300400500600700 -100

-100

-80

-60

-40

-20

0

0100200300400500600700 -100

Distance (m)

Depth (m) Depth (m) Depth (m) Depth (m) Depth (m) Depth (m)

A'

F'

E'

D'

C'

B'

F

E

D

C

B

A

19°41' N

19°40'

156°2'30" W 156°2' 156°1'30"

Kilometers

0 1

Base of escarpment

Top of escarpment

Selected profile locations

Fathometer tracklines

SHOALS data

Fathometer data

A‘

F‘

E‘

D‘

C‘

A B‘

B

C

D

E

F
28 Kaloko-Honok–

ohau National Historical Park, Hawai`i

m in the north to near 22 m in the south. The entire habitat is 

located in water depths between 15 and 30 m and is entirely 

classified as uncolonized volcanic pavement. 

Pinnacles/Ridges

 The pinnacles/ridges habitat zone is dominated by a 

region of pinnacles, ridges, and arches in depths of about 9 to 

25 m of water in the northern part of Honokōhau Bay, between 

Kaloko Fishpond and Kaloko Point. The habitat zone extends 

~50-150 m across the shelf before transitioning, as an irregular, steep escarpment, to the deep sloping shelf habitat below. 

Two noncontiguous, but structurally similar pinnacles are also 

located south of Kaloko Point, surrounded by the irregular 

intermediate bench habitat. 

 The pinnacles/ridges habitat marks a well-defined 

transition from the generally smooth, gently sloping surface 

of the intermediate bench habitat to an irregular, undulating, 

and mounded surface, where the pinnacles rise more than 5 

m from the adjacent sea floor to within 5 m of the surface. 

The ridges and intervening channels are typically oriented 

in a shore-normal direction. The geological origin of these 

structures is unclear, although we speculate they represent a 

more viscous composition of the lava during deposition, which 

would have resulted in significant heaving and fracturing as 

the flow was deposited and cooled. 

The intricate structure and vertical relief in this area 

results in a wide range of coral cover and diversity—with 

some of the highest percentages of coral cover in the park 

being observed in this region (fig. 28). Relative topographic 

highs have low (10 to <50 percent) to moderately high (50 to 

<90 percent) coral cover of predominantly P. meandrina and 

Porites sp., while the intervening lows are typically uncolonized pavement with a thin cover of sand and rubble. Where 

tops of the ridges and pinnacles reach close to the water 

surface, coral cover is typically low to moderate and predominantly P. meandrina and small and encrusting P. lobata. Along 

the edges and walls of these shallower features, and in general 

as water depth increases, percent coral cover and diversity 

increases. Some evidence of onshore/offshore flow transport, 

such as ripple patterns in sand channels, suggests that the 

intervening lows between the pinnacles and ridges are the primary transport pathways for water moving on and off the shelf 

during tidal changes and storm conditions. 

Figure 27. Representative photos of the shelf break and shelf escarpment habitat zones. A, Moderately high coral 

cover on shelf break. B, Closeup of A showing skeletal P. compressa framework with some regrowth at the tips; 

the two red laser points are 10 cm apart. C, Scattered coral and rubble on shelf escarpment. D, Closeup of C

showing greater coral diversity and a more massive coral/rubble framework. 
Results 29

Deep Slope

The deep slope habitat zone is the largest habitat zone 

mapped within the study area. The deep slope fronts the entire 

study area and is predominantly a gently sloping, uncolonized sand sheet. In places, coral rubble, scattered rocks, and 

large angular and rounded boulders are present. The habitat 

begins at the base of the shelf escarpment, deep cliff, and the 

pinnacles/ridges habitats, where there is a distinct transition 

from rubble and rock-covered or exposed volcanic pavement 

to predominantly sand. Where fronting the shelf escarpment 

habitat, the transition to sand is clearly imaged in the video but 

is beyond the limit of the lidar bathymetry; thus, the absolute 

depth of the transition is poorly known. Limited fathometer 

data indicates that the base of the shelf escarpment is between 

about 60 and 80 m of water. It is at this change in slope to a 

mostly low-lying or gently sloping surface where we interpret 

the start of the deep slope habitat zone (fig. 26). This habitat 

is mostly uncolonized; however, small colonies of lobate P. 

lobata were observed in small percentages on some of the 

boulders (fig. 29). Sea cucumbers and garden eels were also 

observed to inhabit this habitat zone.

Regional Patterns of Coral Cover

The habitat zones discussed above describe the structure 

of the volcanic flows that form the substrate of the park, the 

nature of that substrate, and the benthic habitats typically 

found there. It is the combination of the geological complexity 

of this substrate, including variations in shelf width, orientation, bathymetry, and corresponding exposure to incident 

wave energy, that results in regional patterns of coral cover 

within the park. These patterns are described in detail for six 

regions that are unique in their morphology and physiography: 

north bench/escarpment, pinnacles, west bench, central bench/

escarpment, harbor embayment, and south bench/escarpment. 

Representative cross sections illustrating the differences in 

shelf width and sea-floor structure between regions are shown 

in figure 30. A detailed description of each region’s geographic extent, morphology, and benthic cover follows.

North Bench/Escarpment

The north bench/escarpment region begins just north of 

Kaloko Fishpond and continues northwest along the coast to 

dsc02156 P4240002

P4240014 k120303_149b_7_crop

A

C D

B

Figure 28. Representative photos of the pinnacles/ridges habitat zone. A, Pinnacle off Kaloko Point. B, Moderately 

high coral cover on shore-normal ridges. C, Moderately high coral cover and platey corals on vertical edge of a 

ridge. D, One of the numerous arches/bridges near Kaloko Fishpond. 
30 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Wawahiwa`a Point and the north boundary of the study area. 

South of Wawahiwa`a Point, the coast is a low-lying volcanic 

platform formed by the 5-3 ka volcanic flow from Hualalai 

Volcano as mapped by Wolfe and Morris (1996). The shore 

platform slopes gently seaward and is, in places, covered 

with small (<0.5 m diameter) rocks. A narrow intertidal zone 

occupies much of the shore platform along this stretch and is 

continuous with the subtidal shallow bench below. No shoreline cliff is present. The shallow bench is narrow (<150 m; 

~50 m avg) and typically wave washed. North of Wawahiwa`a 

Point, the shoreline/intertidal zone is sandy and the shallow 

bench broadens to nearly 300 m. The entire reach is fronted by 

the submerged shallow cliff, ~1 to 5 m high. The face of this 

cliff is riddled with caves, arches, and other volcanic features 

that attract many scuba divers to the area, as indicated by the 

numerous mooring buoys located nearby (fig. 26). Below this 

cliff, the intermediate bench is relatively narrow (<100 m) and 

slopes gently (<12°) seaward to the shelf break in water depths 

between about 12 and 18 m. Sea-floor slope increases dramatically beyond the break on the steep shelf escarpment, where 

slopes reach 45° and water depths exceed the limit of the lidar 

data (~ 40 m) (fig. 31). 

Benthic habitats in this area are largely controlled by 

sea-floor slope and exposure to wave energy. On the shallow, 

flat, wave-washed bench, coral cover is typically low (10 to 

<50 percent) and almost entirely limited to isolated heads of 

P. meandrina on volcanic pavement. Between the base of the 

cliff and shelf break, the sea floor is mostly covered with large 

volcanic boulders (1-2 m in diameter) or scattered rocks on 

volcanic pavement. Coral colonization is predominantly low 

(10 to <50 percent), except around Wawahiwa`a Point, where 

moderate (50 to <90 percent) coverages were observed. The 

coral community is almost entirely composed of P. meandrina, 

a species that is well suited for shallow, high wave energy 

environments. Secondary amounts of encrusting and small 

colonies of P. lobata also inhabit this zone. Larger heads of P. 

lobata were infrequently observed between and in the lee of 

large boulders (figs. 32-34). 

 The shelf break habitat in this region is typically colonized volcanic pavement with low to moderately high percentages of coral. North of Wawahiwa`a Point, coral cover is 

typically low (10 to <50 percent) and a combination of both P. 

meandrina and P. lobata. Areas of locally higher percentages 

of coral (50 to <90 percent) associated with scattered boulders 

and rocks are found off Wawahiwa`a Point. South of the Point, 

110_1041 dsc2149

IMG-00561900 IMG-00425215

A

C D

B

Figure 29. Representative photos of the deep slope habitat zone. A, Angular boulders at base of shelf escarpment. 

B, Uncolonized rubble and sand at base of shelf escarpment. C, Rocks and sand at base of shelf escarpment. D, 

Rubble and possibly accreted carbonate reef.
Results 31

Figure 30. Cross-shelf profiles of the six regions described in the report, illustrating how the shelf width, offshore slope, 

and sea-floor character vary within the KAHO park area. The vertical and horizontal scales are the same for each section, 

and the maximum depth is limited by lidar penetration. Vertical exaggeration for all profiles is x6.

19°41' N

19°40'

Kilometers

0 1

156°2' W

North bench/escarpment

Pinnacles

West Bench

Central bench/escarpment

Harbor embayment

South bench/escarpment

Profiles

Regions

A

C

B

F

E

D

Depth (m)

40

30

20

10

0

-10

-1000100200300400500600700800

C. West Bench

Distance offshore (m)

Depth (m)

40

30

20

10

0

-10

-1000100200300400500

B. Pinnacles

Distance offshore (m)

Depth (m)

40

30

20

10

0

-10

-1000100200

F. South Bench/

Escarpment

Distance offshore (m)

Depth (m)

40

30

20

10

0

-10

-1000100200300400500600700800

D. Central Bench/Escarpment

Distance offshore (m)

40

30

20

10

0

-10

-1000100200

A. North Bench/

Escarpment

Distance offshore (m) Depth (m)

Distance offshore (m)

40

30

20

10

0

-10

-1000100200300400

E. Harbor Embayment
32 Kaloko-Honok–

ohau National Historical Park, Hawai`i

coral cover and the relative percentage of P. lobata generally 

increase. An east-west-trending band of moderately high coral 

cover (50 to <90 percent) found off the relatively protected 

south-facing shoreline in this region contains the highest 

percentage and diversity of coral, dominated by P. lobata with 

lesser amounts of P. meandrina and P. compressa on volcanic 

pavement. 

The shelf escarpment in this region is characterized by 

thin, patchy assemblages of primarily P. compressa (10 to 

<50 percent). Along nearly this entire stretch, the coral habitat 

is characterized by thin, rubbly P. compressa framework. 

The relatively high concentrations of P. compressa framework suggest that the reef may have thrived in the past, but 

at present is mostly dead and shows sign of stress and wave 

damage. Thicker accumulations with higher percentages of 

live coral are found on relatively less steep portions of the 

escarpment and where the habitat is more protected from 

incident wave energy, such as within the embayment off Lone 

Tree Arch mooring buoy. Overall, live coral cover decreases 

with increasing water depth, with mostly <10 percent live 

coral cover on rubble and volcanic pavement in water deeper 

than about 30 m. Uncolonized rubble, scattered rocks, and 

boulders mark the transition to an uncolonized sand sheet at 

the (inferred) base of the escarpment. The actual depth and 

reason for this transition to sand are unknown, as it is beyond 

the depth limit of the lidar data. 

In general, the relative percentage of P. meandrina

decreases seaward and the relative percentages of both P. 

lobata and P. compressa increases seaward in the north bench/

escarpment region. The highest overall coral cover is found in 

the intermediate bench and shelf break habitat zones, between 

Wawahiwa`a Point and the Lone Tree Arch mooring buoy, 

where the shelf break is relatively wider and semiprotected 

from the incident north Pacific swell.

Pinnacles

The pinnacles region abuts the north bench/escarpment 

region in the north and both the west bench and central bench/

156°2'30" W

19°41'20"

19°41'40" N

Meters

0 250

Suck 'Em Up

Skunk Hollow 2 Lone Tree Arch

Skunk Hollow 1

Freeze-Face Cave

Pyramid Pinnacles/Drop-off A

Wawahiwa`a Point

15

5

30

10

Shoreline/intertidal

Shallow cliff

Shallow bench–narrow

Shallow bench–broad

Intermediate bench

Shelf break

Shelf escarpment

Pinnacles/ridges

Deep slope

No bathmetric data

Profile

Isobath, interval 5 m

Mooring buoys 

North bench/escarpment

Habitat zones

Figure 31. Habitat zones of the north bench/escarpment region of KAHO overlaid on shaded relief bathymetry. Hatched lines 

indicate areas lacking bathymetric data. Line A shows the location of the cross-shelf profile shown in figure 33.
Results 33

156°2'30" W 156°2'

19°41'20"

19°41'40" N

Meters 

0 250

Suck 'Em Up

Skunk Hollow 2

Lone Tree Arch

Skunk Hollow 1

Freeze-Face Cave

Pyramid Pinnacles/Drop-off A

Wawahiwa`a Point

30

10

North bench/escarpment

Benthic habitat classes

Sand, uncolonized

Volcanic pavement w/ 10–50% rocks/boulders, uncolonized

Volcanic pavement w/ 10–50% rocks/boulders, 10–<50% coral

Volcanic pavement w/ 10–50% rocks/boulders, 50–<90% coral

Volcanic pavement, uncolonized

Volcanic pavement,10–<50% coral

Volcanic pavement, 50–<90% coral

Volcanic pavement w/ >50% rocks/boulders, 10–<50% coral

Volcanic pavement w/ >50% rocks/boulders, 50–<90% coral

Other, artificial/historical

No bathymetric data

Profile

Isobath, interval 5 m

Mooring buoys

Figure 32. Benthic habitat classifications of the north bench/escarpment region of KAHO overlaid on shaded relief bathymetry. 

Hatched lines indicate areas lacking bathymetric data. Line A shows the location of the cross-shelf profile shown in figure 33.
34 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Figure 33. Cross-shelf profile (A) and typical benthic habitat transitions of the north bench/

escarpment region of KAHO. Vpave = volcanic pavement. Vertical exaggeration is x2.

Figure 34. Three-dimensional perspective view of the north bench/escarpment region of KAHO, showing benthic habitat classifications 

draped on lidar bathymetry. The colors are the same as in figure 32. The red line is the shoreline, and the black line is the 20-m isobath. 

Habitat classifications are displayed only where lidar data exist. Vertical exaggeration is x3. View is toward the northeast. Approximate 

distance along the bottom of the figure is 1 km.

Distance offshore (m)

Depth (m)

250 200 150 100 50 0 -50

50

40

30

20

10

0

-10

Cliff

Intermediate bench

Shallow bench

Shelf escarpment

Shelf break

S N

Low-moderate coral on rocks and boulders 

(P. lobata; P. meandrina)

Low coral on Vpave

(P. meandrina)

Low coral on Vpave (P. compressa)

Moderate coral on Vpave (P. lobata)

Uncolonized Vpave

A. North Bench Intertidal

Uncolonized

rocks and boulders
Results 35

escarpment regions in the south (fig. 35). The shoreward 

boundary of this region is marked by the wall fronting Kaloko 

Fishpond and the generally low-lying volcanic platform of the 

5-3 ka volcanic flow as mapped by Wolfe and Morris (1996). 

As with the north bench/escarpment, a narrow intertidal zone 

fronts the shoreline south of the fishpond and is continuous 

with the shallow bench habitat. The shallow bench fronts 

the entire shoreline in this region. Directly west of Kaloko 

Fishpond it is broader (as much as ~150 m) and shallower (< 

~3 m) than to the north and south (where it is < 5 m deep and 

~50 m wide). In all areas it is a flat, pahoehoe-type volcanic 

pavement, with scattered rocks and boulders only off Kaloko 

Fishpond and along the shoreline and intertidal reaches. 

Low amounts of coral (10 to <50 percent), primarily 

isolated heads of P. meandrina with lesser amounts of small 

lobate and encrusting colonies of P. lobata, colonize the 

subtidal portions of the shallow bench north of Kaloko Point 

(figs. 36-38). To the south, higher incident wave energy focusing around the Point causes the bench to be wave washed. 

Because of this, we classify the shallow bench in this area as 

uncolonized (< 10 percent) volcanic pavement. A low cliff 

(~1-2 m high) separates the shallow bench from the deeper 

intermediate bench below. The cliff is mostly continuous 

throughout this area, except for a ~45-m stretch off the central 

part of Kaloko Fishpond. 

The intermediate bench habitat extends from the base 

of the cliff across the shelf to about 10-m depth, a distance 

of between about 30 and 120 m (~80 m avg). North of 

Kaloko Point, the surface slopes gently seaward and consists 

of smooth pahoehoe-type volcanic pavement covered with 

boulders and scattered rocks. Larger and more densely packed 

boulders exist closer to shore. Coral cover and diversity in this 

habitat increases from low (10 to <50 percent) near the base 

of the cliff to moderately high (50 to <90 percent) as water 

depth and distance from the cliff increase. Some boulders are 

nearly entirely obscured by coral growth, and large mushroom-shaped colonies of Porites evermanni are characteristic 

of this area of the park. West and south of Kaloko Point, the 

character of the volcanic pavement on the bench becomes 

undulating and irregular, the bench is covered with boulders 

and rocks in places, and coral cover is typically low (10 to <50 

percent).

Beginning at a depth of about 10 m of water and 

continuing across the shelf into 18 to 25 m of water, the 

pinnacles/ridges habitat dominates the sea floor between 

Kaloko Fishpond and Kaloko Point. Small pinnacle areas 

156°2'20'' W 156°2' 156°1'40"

19°41'

19°41'10"N

Meters

0 250

B Fishpond

Shoreline/intertidal

Shallow cliff

Shallow bench–narrow

Intermediate bench

Deep bench

Shelf break

Shelf escarpment

Pinnacles/ridges

Deep cliff

Deep slope

No bathymetric data

Profile

Isobath, interval 5 m

Mooring buoys 

Pinnacles

Habitat zones

Windows

Kaloko Arches 2

Kaloko Ledges 1

Kaloko Point

Kaloko

Fishpond

20

10

30

Figure 35. Habitat zones of the pinnacles region of KAHO overlaid on shaded relief bathymetry. Hatched lines indicate areas 

lacking bathymetric data. Line B shows the location of the cross-shelf profile shown in figure 37.
36 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Figure 36. Benthic habitat classifications of the pinnacles region of KAHO overlaid on shaded relief bathymetry. Hatched 

lines indicate areas lacking bathymetric data. Line B shows the location of the cross-shelf profile shown in figure 37.

156°2'20'' W 156°2'10'' 156°2' 156°1'50" 156°1'40"

19°41'

19°41'10"N

Meters

0 250

B

Windows

Kaloko Arches 2

Kaloko Ledges 1

Kaloko Point

Kaloko

Fishpond

20

10

30

Pinnacles

Benthic habitat classes

Sand, uncolonized

Volcanic pavement w/10–50% rocks/boulders,

uncolonized

Volcanic pavement w/10–50% rocks/boulders,

10–<50% coral

Volcanic pavement w/10–50% rocks/boulders,

50–<90% coral

Volcanic pavement, uncolonized

Volcanic pavement,10–<50% coral

Volcanic pavement, 50–<90% coral

Volcanic pavement w/>50% rocks/boulders,

10–<50% coral

Volcanic pavement w/>50% rocks/boulders,

50–<90% coral

Other, artificial/historical

No bathymetric data

Profile

Isobath, interval 5 m

Mooring buoys

Intermediate bench

Deep slope

Pinnacles and ridges

600 500 400 300 200 100 0 -100

Distance offshore (m)

Depth (m)

B. Pinnacles Intertidal/shallow bench

Cliff

Low-moderate coral on rocks and boulders

(Porites sp.; P. meandrina)

Uncolonized Vpave

Moderate coral on Vpave

(Porites sp.)

Sand

Uncolonized to low 

coral on rocks and 

Vpave (P. meandrina)

20

10

0

-10

40

30

NW SE

Figure 37. Cross-shelf profile (B) and typical benthic habitat transitions of the pinnacles 

region of KAHO. Vpave = Volcanic Pavement. Vertical exaggeration is x4.
Results 37

associated with the irregular surface of the intermediate 

bench are present just south of Kaloko Point. West of Kaloko 

Fishpond, the pinnacles are colonized with a typically thin 

but moderately high (50 to <90 percent) cover of coral, 

with relatively high community diversity. The intervening 

bathymetric lows between the pinnacles are typically 

uncolonized volcanic pavement with some coral rubble and 

sand. A large sand sheet separates two areas of pinnacles off 

the southern end of Kaloko Fishpond. Shore-normal ridges 

in the northern part of the embayment support relatively 

higher percentages of coral (approaching 90 to 100 percent) 

and locally have vertically accreted carbonate reef. In places, 

the benthic habitat in this region is similar to and difficult to 

distinguish from the volcanic pavement with sand channels 

observed in the southern part of Honokōhau Bay. 

West and south of the headland at Kaloko Point, the coral 

cover on the pinnacles and ridges drops to 10 to <50 percent 

in water depths less than about 16 m. On the escarpment 

fronting the pinnacles, in water depths between about 16 and 

25 m, coral cover is moderately high (50 to <90 percent) and 

consists primarily of P. compressa and P. lobata. Locally, coral 

cover approaches 90 to 100 percent with possible aggregate 

reef accretion. 

The pinnacles region ends along a well-defined edge in 

water depths of around 20 to 25 m, where the sea-floor structure 

transitions to a relatively smooth and moderately sloping, 

deep-water shelf. The deep shelf comprises a poorly colonized 

volcanic pavement and uncolonized sand with rubble and 

angular boulders. A few small colonies of lobate P. lobata were 

observed on the pavement and boulders in this environment.

The great bathymetric relief, relatively high and diverse 

coral cover, and interesting structural features in this area 

provide rich habitat for fish and make it an attractive area 

for recreational diving and snorkeling activities. Culturally, 

this area was heavily used by native Hawaiians (Greene, 

1993; Hoover and Gold, 2005), and the pinnacles likely 

provided high-quality fishing opportunities. It is possible that 

submerged archeological sites and/or artifacts associated with 

these offshore fishing grounds may be found in the area.

West Bench

The west bench region is bounded by the pinnacles region 

to the north and central bench/escarpment region to the south 

and comprises the deep bench, deep cliff, and deep slope habitats 

(fig. 39). The west bench is slightly (1–3 m) but distinctly lower 

than the adjacent regions, and the landward extent is defined by a 

Figure 38. Three-dimensional perspective view of the pinnacles region of KAHO, showing benthic habitat classifications draped on 

lidar bathymetry. The colors are the same as in figure 36. The red line is the shoreline, and the black line is the 20-m isobath. Habitat 

classifications are displayed only where lidar data exist. Vertical exaggeration is x3. View is toward the east. Approximate distance 

along the bottom of the figure is 0.7 km.
38 Kaloko-Honok–

ohau National Historical Park, Hawai`i

low cliff or step that marks the transition. Relative to other areas 

in the park, the benthic habitat in west bench region is the most 

poorly colonized and least diverse of all the regions. The bench 

is generally flat to gently rolling pahoehoe with mostly low coral 

cover of primarily small lobate P. lobata and P. meandrina and 

patches of uncolonized pavement, sand, and rubble. Locally 

there are areas of higher coral cover with larger heads of lobate P. 

lobata. A relatively large sand sheet abuts the intermediate bench 

of the central bench/escarpment region (figs. 40-42). 

The deep cliff fronts and defines the west bench habitat. 

Below this cliff the sea floor is a sloping shelf covered with 

scattered rocks, large boulders, and rubble on a veneer of sand 

on volcanic pavement. Isolated colonies of small P. lobata

colonize the boulders to a depth of about 33 m. A sharp and 

distinct contact between this rocky, rubbly pavement and 

uncolonized sand was observed in the video, although the 

absolute position and depth of this transition are unknown as it 

is beyond the limit of the lidar data. Fathometer data show that 

the sloping shelf continues to about 45-m water depth where at 

least one other cliff and bench are encountered before the base 

of the slope is reached and the shelf flattens, in about 70-m 

water depth. The base of this slope is likely the boundary of 

the uncolonized sand field (fig. 26). 

Central Bench/Escarpment

The central bench/escarpment is the largest region within 

the study area. It extends about 1,300 m alongshore, from 

about 300 m south of Kaloko Point to Honokōhau Harbor, and 

from the shoreline to nearly 1 km offshore. It is dominated by 

the broad shallow bench habitat zone, but also includes the 

intertidal, intermediate bench, shelf break, shelf escarpment, 

and deep slope habitat zones (fig. 43). 

The shoreline backing the majority of the central bench/

escarpment is the 10-5 ka volcanic flow, except for a ~170-m 

stretch in the northern part of the region where the 5-3 ka flow 

reaches the coast (Wolfe and Morris, 1996). Intertidal habitat 

found along the entire stretch of this region is a combination 

Figure 39. Habitat zones of the west bench region of KAHO overlaid on shaded relief bathymetry. Hatched lines indicate areas lacking 

bathymetric data. Line C shows the location of the cross-shelf profile shown in figure 41. 

156°2'20'' W 156°2'

19°40'40"

19°40'50"

19°41'N

Meters

0 250

C

Shoreline/intertidal

Shallow cliff

Shallow bench–narrow

Shallow bench–broad

Intermediate bench

Deep bench

Shelf break

Shelf escarpment

Pinnacles/ridges

Deep cliff

Deep slope

No bathymetric data

Profile

Isobath, interval 5 m

 

West bench

Habitat zones

10

20

30
Results 39

Figure 40. Benthic habitat classifications of the west bench region of KAHO overlaid on shaded relief bathymetry. Hatched lines 

indicate areas lacking bathymetric data. Line C shows the location of the cross-shelf profile shown in figure 41.

Figure 41. Cross-shelf profile (C) and typical benthic habitat transitions of the west bench 

region of KAHO. Vpave = Volcanic Pavement. Vertical exaggeration is x4.

156°2'20''W 156°2'

19°40'40"

19°40'50"

19°41'N

Meters

0 250

C 10

20

30

West bench

Benthic habitat classes

Sand, uncolonized

Volcanic pavement w/10–50%

rocks/boulders, uncolonized

Volcanic pavement w/10–50%

rocks/boulders, 10–<50% coral

Volcanic pavement, uncolonized

Volcanic pavement, 10–<50% coral

Volcanic pavement, 50–<90% coral

Volcanic pavement, 50–<90%

octocoral

Volcanic pavement w/ >50%

rocks/boulders,10–<50% coral

Reef rubble

No bathymetric data

Profile

Isobath, interval 5 m

Cliff

Intermediate bench

Shallow bench

Deep slope

Deep bench

Cliff

Cliff

Distance offshore (m)

Depth (m)

600 500 400 300 200 100 0 -100

Uncolonized Vpave

Uncolonized-low coral on 

boulders, rubble, and sand

(small P. lobata)

Low coral 

on rocks and Vpave

(P. lobata; P. meandrina)

Low coral on Vpave

(P. lobata)

40

30

20

10

0

-10

W E

C. West Bench
40 Kaloko-Honok–

ohau National Historical Park, Hawai`i

of uncolonized rocks, sand, and flat volcanic pavement 

covered with undifferentiated algae. No shoreline cliff is 

present, and the intertidal zone transitions to the shallow bench 

habitat as water depth exceeds about 1 m.

The benthic habitat of the shallow bench in this region 

is relatively homogeneous (figs. 44-46). In water depths less 

than about 2 m, hard corals are rare, and the octocoral Anthelia 

edmonsoni covers the volcanic pavement like a carpet. In 

deeper water, low percentages (10 to <50 percent) of coral 

colonize mostly flat volcanic pavement or scattered rocks. 

Coral diversity is typically low and dominated by small lobate 

colonies of P. lobata and P. meandrina. Coral abundance 

generally increases as water depth and distance offshore 

increase. Near the seaward edge of the shallow bench, the 

sea floor is more fractured and heaved, forming ledges and 

crevices that support slightly higher, although still <50 

percent, coral cover.

Near the 5-m isobath, the shallow cliff marks the end of 

the shallow bench and beginning of the intermediate bench 

habitat. The intermediate bench extends along the entire 

stretch of the central bench/escarpment region. From the 

base of the shallow cliff to about the 11-m isobath, a nearly 

continuous cover of large (1-2 m), rounded boulders sits on 

the volcanic pavement. The boulders are typically poorly 

colonized (10 to <50 percent) by small colonies of P. lobata. 

Between the boulders, rubble and smaller rocks are colonized 

with slightly higher percentages (still <50 percent) of coral, 

including larger colonies of P. lobata as well as some P. 

compressa. There are local areas of boulder-free pavement and 

higher coral cover. 

Near the 11-m isobath, the benthic habitat on the 

intermediate bench changes dramatically. South of about 

19° 40’ 20” (2178000 N), shore-normal ridges of volcanic 

pavement separated by sand and rubble-filled channels 

become the dominant substrate structure. Nearly continuous, 

moderately high (50 to <90 percent) to high (90 to 100 

percent) coral cover is distributed over the ridges. Some large 

boulders are also integrated with the coral growth. The coral 

community in this area appears to be thriving and very healthy. 

Diversity is relatively high, with a variety of species and forms 

comprising mostly P. lobata and P. compressa. In some places 

Figure 42. Three-dimensional perspective view of the west bench region of KAHO, showing benthic habitat classifications draped on 

lidar bathymetry. The colors are the same as in figure 40. The red line is the shoreline, and the black line is the 20-m isobath. Habitat 

classifications are only displayed where lidar data exist. Vertical exaggeration is x3. View is toward the northeast. Approximate distance 

along the bottom of the figure is 1.5 km.
Results 41

156°2'10'' W 156°2' 156°1'50" 156°1'40"

19°40'40''

19°40'20''

19°41' N

Meters

0 250

B

Shoreline/intertidal

Dredged

Shallow cliff

Shallow bench–narrow

Shallow bench–broad

Intermediate bench

Deep bench

Deep cliff

Shelf break

Shelf escarpment

Pinnacles/ridges

Deep slope

No bathymetric data

Profile

Isobath, interval 5 m

Mooring buoys 

Central bench/escarpment

Habitat zones

Maliu Point

`Aimakapä

 Fishpond

30

10

20

Turtle Pai

Turtle

Heaven

Kaloko

Arches 2

Kaloko

Ledges 1

Turtle

Pinnacle

Terrapin

Station

Turtle Pai

Turtle

Heaven

Kaloko

Arches 2

Kaloko

Ledges 1

Turtle

Pinnacle

Terrapin

Station

Figure 43. Habitat zones of the central bench/escarpment region of KAHO overlaid on shaded relief bathymetry. 

Hatched lines indicate areas lacking bathymetric data. Line D shows the location of the cross-shelf profile 

shown in figure 45. 
42 Kaloko-Honok–

ohau National Historical Park, Hawai`i

156°2' W

19°40'40''

19°40'20''

19°41' N

Meters

0 250

D

Maliu Point

10

20

Turtle Pai

Turtle

Heaven

Kaloko

Arches 2

Kaloko

Ledges 1

Turtle

Pinnacle

Terrapin

Station

Turtle Pai

Turtle

Heaven

Kaloko

Arches 2

Kaloko

Ledges 1

Turtle

Pinnacle

Terrapin

Station

`Aimakapä

 Fishpond

Pinnacles—Benthic habitat classes

Sand, uncolonized

Volcanic pavement w/10–50% 

rocks/ boulders,uncolonized

Volcanic pavement w/10–50% 

rocks/ boulders, 10–<50% coral

Volcanic pavement w/10–50% 

rocks/boulders, 50–<90% coral

Volcanic pavement, uncolonized

Volcanic pavement, 10–<50% coral

Volcanic pavement, 50–<90% coral

Volcanic pavement, 50–<90% 

octocoral

Volcanic pavement w/>50% 

rocks/boulders, uncolonized

Volcanic pavement w/>50% rocks/ 

boulders, 10–<50% coral

Volcanic pavement w/>50% rocks/ 

boulders, 50–<90% coral

Volcanic pavement w/sand 

channels, 50–<90% coral

Volcanic pavement w/sand 

channels, 90–100% coral

Other, artificial/historical

No bathymetric data

Profile

Isobath, interval 5 m

Mooring buoys 

Figure 44. Benthic habitat classifications of the central bench/escarpment region of KAHO overlaid on shaded relief 

bathymetry. Hatched lines indicate areas lacking bathymetric data. Line D shows the location of the cross-shelf profile 

shown in figure 45. 
Results 43

Distance offshore (m)

Depth (m)

600 500 400 300 200 100 0 -100

40

30

20

10

0

-10

D. Central Bench Cliff

Intermediate bench

Shallow bench

Shelf 

escarpment

Shelf break

Shoreline/Intertidal

Uncolonized

Vpave

Low coral on rocks and boulders (P. lobata)

Low coral on Vpave

(small P. lobata; P. meandrina; octocoral)

Moderate coral on Vpave (P. lobata; P.compressa)

Uncolonized-low coral on Vpave and rubble

(P. compressa; P.lobata)

SW NE

Figure 45. Cross-shelf profile (D) and typical benthic habitat transitions of the west bench 

region of KAHO. Vpave = Volcanic Pavement. Vertical exaggeration is x4.

Figure 46. Three-dimensional perspective view of the central bench/escarpment region of KAHO, showing benthic habitat 

classifications draped on lidar bathymetry. The colors are the same as in figure 44. The red line is the shoreline, and the black line is the 

20-m isobath. Habitat classifications are displayed only where lidar data exist. Vertical exaggeration is x3. View is toward the northeast. 

Approximate distance along the bottom of the figure is 0.5 km.
44 Kaloko-Honok–

ohau National Historical Park, Hawai`i

there may be aggregated reef or carbonate accumulation. 

Overall, however, the underlying volcanic pavement is still 

visible despite the high coral cover. 

North of about 19° 40’ 20” (2178000 N), there is a 

relatively distinct transition from the volcanic pavement and 

sand channels to volcanic pavement covered with scattered 

rocks, boulders, and coral rubble. Coral cover is variable, 

with low (10 to <50 percent) to moderate (50 to <90 percent) 

coral cover of predominantly P. lobata. A band of colonized 

pavement on the seaward edge of the intermediate bench near 

the north boundary of the central region shows somewhat 

higher coral cover and community diversity, with moderately 

high (50 to <90 percent) cover of P. lobata and P. compressa. 

Overall, coral cover decreases toward the north and the 

adjoining west bench region.

The shelf break habitat fronting the central bench/

escarpment region, between about 14 and 27 m water depth, 

is a fairly continuous stretch of volcanic pavement with 

moderately high (50 to <90 percent) coral cover of primarily 

P. lobata and P. compressa. Coral cover on the shelf break 

decreases to low (10 to <50 percent) percentages of mostly P. 

lobata in the northern part of the central region near the west 

bench region.

A well-defined shelf escarpment habitat fronts the central 

bench/escarpment region between the harbor embayment in 

the south and the deep cliff of the deep bench region in the 

north. The benthic habitat is characterized predominantly by 

thin, patchy P. compressa, skeletal P. compressa framework, 

and coral rubble on volcanic pavement. Where the offshore 

slope increases to ~>30°, little continuous P. compressa or 

framework exists and the slope is predominantly covered with 

scattered rocks and low amounts of live P. compressa and P. 

lobata. The habitat is mostly uncolonized below about 30-m 

depth. The mapped transitions in habitat in this region are 

approximate, because of the extreme offshore slope and water 

depth. 

An uncolonized sand sheet fronts the entire stretch of 

the central bench/escarpment region. A sharp and distinct 

contact between the uncolonized rocks, rubble, and pavement 

of the shelf escarpment habitat and the sand was observed 

in video. The depth and location of this contact are poorly 

known. It is delineated from the few video transects that 

cross the transition, and the position is somewhat subjective. 

Limited fathometer data show a break in slope at a water depth 

of about 60 m, and we infer this to be the base of the shelf 

escarpment. If this base of the escarpment is coincident with 

the transition in habitats, the position is about 75 m farther 

offshore than delineated on our maps (fig. 26). 

Overall, the central bench/escarpment region supports 

some of the most diverse and complex habitat observed within 

the park. The region includes all the habitat classes observed 

except aggregated reef and reef rubble. With the extensive 

shallow habitat, the high coral cover associated with the 

pavement and sand channels north of the harbor, and the easy 

access along much of the shoreline, the area is popular with 

scuba divers and snorkelers. Many fish were observed along 

the shallow cliff and boulder regions, as were sea turtles in the 

shallows. 

Harbor Embayment 

Some of the highest and lowest coral cover in the study 

area is located off the mouth of the Honokōhau Harbor. 

The boundary of this region is defined by the embayment 

fronting the harbor, and it overlaps some of the central bench/

escarpment and south bench/escarpment regions (fig. 47). The 

orientation of the coast and sea floor changes dramatically 

here, from a mostly north-south orientation north of the 

embayment, to a northeast-southwest orientation to the south. 

The morphology of the sea floor is similar to elsewhere in 

the park, where a shallow bench drops to an intermediate 

bench and then over a steep escarpment to a deep slope below. 

Unique to this area, however, is the presence of a sand sheet at 

the base of the shelf escarpment, in about 25 m of water, and a 

dredged channel off the harbor mouth. 

The 3.0 to 1.5 ka volcanic flow (Wolfe and Morris 

1996), the youngest of the three present in the park, forms the 

coastline between Maliu Point and the south end of the study 

area. Between Maliu Point and Alula Bay, the coast is fairly 

low lying and nearly continuous with the offshore shallow 

bench habitat. A gap in the lidar data exists in this area, so 

elevation and depth information are limited to qualitative 

field observations. Intertidal and shallow bench habitats 

characterize the shoreline from Maliu Point south to about 

130 m west of Alula Bay. The shallow bench was likely 

continuous across the mouth of the harbor before the dredging 

of the channel associated with harbor construction. The 

shallow bench comprises poorly colonized rocks, boulders, 

and volcanic pavement. Low-lying species such as encrusting 

Porites species and the octocoral Anthelia edmonsoni inhabit 

these shallow-water areas. Uncolonized sand and some 

boulders exist within Alula Bay. The easy access and shallow, 

protected waters in Alula Bay makes it a popular spot for 

visitors and snorkelers. The boundary between this region 

and the south bench/escarpment is somewhat subjective and 

is defined by the southward limit of the shallow bench habitat 

and the western boundary of Alula Bay (figs. 47–51).

In the dredged zone at the mouth of the harbor, the 

benthic habitat is predominantly poorly colonized pavement 

and rocks. Scattered P. meandrina and P. lobata are the 

common species. Numerous tires and other debris were 

observed in this region, along with areas of higher (still 

<50 percent) coral cover near the south wall of the dredged 

channel. 

The majority of the harbor embayment region is the 

intermediate bench habitat. In water depths less than about 

10 m, the habitat is characterized by a near-continuous 

cover of large (1-2 m diameter) rounded boulders, colonized 

with 10 to <50 percent of primarily lobate and encrusting 

P. lobata and scattered heads of P. meandrina. In some 

areas coral cover on the boulders exceeds 50 percent. Near 

the 10-m isobath, the sea-floor structure and coral cover 
Results 45

change dramatically, from the boulder-covered pavement to 

predominantly shore-normal ridges of volcanic pavement 

and intervening sand and channels. The ridges are generally 

less than 2 m high (fig. 50) and are almost completely 

colonized with coral. The coral community structure is 

relatively diverse compared to other areas of the park, but 

still dominated by P. lobata, with lesser amounts of other 

Porites species, including P. compressa and P. evermanni. 

These features are differentiated from the spur-and-groove 

structure by their diminutive size, lack of continuity, and 

little vertical accretion of coral. 

Adjacent to this area of thriving coral communities west 

of the harbor mouth is a zone of poorly colonized scattered 

rocks, volcanic pavement, and sand channels (fig. 48). The 

absolute boundaries of this degraded area are poorly known; 

limited survey transects crossed this area, and no obvious 

differences in bottom character are evident in the aerial 

photography. However, relatively sharp transitions from 

moderately high and high to low coral cover are observed at 

both the north and south boundaries of this zone. The bottom 

structure across this boundary is apparently similar to the 

shore-normal ridges characteristic of the highly colonized area 

to the north, but with distinctly lower coral cover. 

The shelf break and shelf escarpment are located just 

seaward of the intermediate bench in water deeper than 

about 19 m. The benthic habitat of the shelf break is similar 

to that observed on the adjacent intermediate bench, but 

with somewhat less coral cover (50 to <90 percent) on the 

volcanic pavement. The shelf escarpment fronting the harbor 

embayment region is not as steep as to the north and south, 

particularly fronting the relatively degraded area, where the 

offshore slope is typically less than 20°. A sharp contact with 

an uncolonized sheet of sand extends seaward from the base of 

the escarpment in about 25 m of water. Elsewhere in the study 

area the base of the shelf escarpment is in water depths greater 

than 40 m.

South Bench/Escarpment

Like the north bench/escarpment region, the south bench/

escarpment region is characterized by a relatively narrow 

intermediate bench that slopes gently seaward from the coast 

before dropping steeply over the shelf escarpment. In contrast to 

the north, however, where the emergent coast is low lying and 

a rocky intertidal zone transitions to a shallow wave-washed 

bench, no shallow bench and little intertidal habitat exists in the 

south. This can be attributed to the younger emergent volcanic 

156°1'50'' W 156°1'40'' 156°1'30"

19°40'10"N

Meters

0 250

Turtle Heaven

Honoko–hau Middle Honoko–hau Inside

Honoko–hau Outside

E F

Maliu Point

Alula Bay

`Ai`a

–pio Fishtrap

10

30

20

Shoreline/intertidal

Dredged

Shallow cliff

Shallow bench–narrow

Shallow bench–broad

Intermediate bench

Shelf break

Shelf escarpment

Deep slope

No bathymetric data

Profile

Isobath, interval 5 m

Mooring buoys 

Harbor embayment

Habitat zones

Figure 47. Habitat zones of the harbor embayment region of KAHO overlaid on shaded relief bathymetry. Hatched lines indicate 

areas lacking bathymetric data. Lines E and F show the locations of the cross-shelf profiles shown in figures 49 and 50.
46 Kaloko-Honok–

ohau National Historical Park, Hawai`i

156°1'50'' W 156°1'40'' 156°1'30"

19°40'10"N

Meters

0 250

Turtle Heaven

Honoko–hau Middle Honoko–hau Inside

Honoko–hau Outside

Maliu Point

Alula Bay

`Ai`a

–pio Fishtrap

Harbor embayment

Habitat zones

Sand, uncolonized

Aggregate reef, 50–<90% coral

Aggregate reef, 90–100% coral

Volcanic pavement w/10–50% 

rocks/boulders, uncolonized

Volcanic pavement w/10–50% 

rocks/boulders, 10–<50% coral

Volcanic pavement w/10–50% 

rocks/boulders, 50–<90% coral

Volcanic pavement, uncolonized

Volcanic pavement, 10–<50% coral

Volcanic pavement, 50–<90% coral

Volcanic pavement, 90–100% coral

Volcanic pavement w/>50% rocks/

boulders, uncolonized

Volcanic pavement w/>50% rocks/

boulders, 10–<50% coral

Volcanic pavement w/>50% rocks/

boulders, 50–<90% coral

Volcanic pavement w/ sand 

channels, 10–<50% coral

Volcanic pavement w/ sand 

channels, 50–<90% coral

Volcanic pavement w/ sand 

channels, 90–100% coral

Reef rubble, uncolonized

Reef rubble, 10–<50% coral

Reef rubble, 50–<90% coral

Other, artificial/historical

No bathymetric data

Profile

Isobath, interval 5 m

Mooring buoys 

E F

10

30

20

Figure 48. Benthic habitat classifications of the harbor embayment region 

of KAHO overlaid on shaded relief bathymetry. Hatched lines indicate areas 

lacking bathymetric data. Lines E and F show the locations of the cross-shelf 

profiles shown in figure 49 and 50. The white line delineates the approximate 

boundary of the degraded area discussed in the text.

Distance offshore (m)

Depth (m)

600 500 400 300 200 100 0 -100

40

30

20

10

0

-10

E. Harbor Embayment Shallow Bench

Intermediate bench

Shelf escarpment

Shelf break

Deep Slope

Low-high coral on rocks and

Vpave w/sand channels

(P. lobata; P.compressa)

Low coral on 

Vpave and rocks

(P. lobata; 

P. meandrina)

Moderate-high coral

on Vpave and rocks

Sand (P. lobata; P.compressa)

Low coral

on rocks 

and Vpave

(P. lobata)

W E

Figure 49. Cross-shelf profile (E) and typical benthic habitat transitions of the harbor embayment 

region of KAHO. Vpave = Volcanic Pavement. Vertical exaggeration is x3.
Results 47

15

14

13

12

11

10

250 200 150 100 50 0

Distance alongshore (m)

Depth (m)

F. Ridges and sand channels (Harbor Bay)

N S

Figure 50. Cross-shelf profile (F) of the ridges and sand channels located on the intermediate 

bench of the harbor embayment region of KAHO. Note the different scale and vertical 

exaggeration from other profiles. Vertical exaggeration is x16.

Figure 51. Three-dimensional perspective view of the harbor embayment region of KAHO, showing benthic habitat classifications 

draped on lidar bathymetry. The colors are the same as in figure 48. The red line is the shoreline, and the black line is the 20-m isobath. 

Habitat classifications are only displayed where lidar data exist. Vertical exaggeration is x3. View is toward the northeast. Approximate 

distance along the bottom of the figure is 0.4 km.
48 Kaloko-Honok–

ohau National Historical Park, Hawai`i

platform located along this part of the coast (3.0-1.5 ka in the 

south versus 5.0-3.0 ka in the north) that ends abruptly at the 

shoreline. West of Alula Bay, a near-vertical cliff rises 2-3 m 

from the surface of the water and drops another ~ 2-3 m to the 

intermediate bench below (fig. 52). 

The intermediate bench, the largest habitat in this 

region, is flat (mean slope = 7°), narrow (50-150 m wide) 

and relatively shallow (<13 m water depth). From the base 

of the cliff to water depths of about 10 m, the sea floor is 

almost completely covered with large, rounded volcanic 

boulders, sparsely colonized (10 to <50 percent) with small 

P. lobata and lesser amounts of P. meandrina. As water depth 

increases toward the shelf break, boulders decrease in size and 

frequency and coral cover is variable. The percentage of P. 

meandrina versus P. lobata increases with water depth and to 

the south, reaching moderately high cover (50 to <90 percent) 

of primarily P. meandrina on and between boulders south of 

Noio Point (figs. 53-55). 

Some of the highest coral cover observed in the park 

(90-100 percent) is located in the south bench/escarpment 

region where the northeast-southwest-trending intermediate 

bench and shelf break habitat zones converge with the more 

gently sloping (~<15°), north-south-trending terrain of the 

intermediate bench zone off the mouth of the Honokōhau 

Harbor (figs. 51, 55). This is the only area where vertically 

accreted or aggregate reef is mapped within the study area. A 

relatively abrupt transition from poorly colonized rocks and 

boulders to moderately high (50 to <90 percent) coral cover 

on rocks and boulders occurs in water depths between 6 and 9 

m. Moderately high to high (90 to 100 percent) coral cover on 

aggregate reef begins in about 9 m of water and continues over 

the shelf break to about 15-m water depth. Nearby mooring 

buoys that were regularly visited by commercial snorkel boats 

during our surveys indicate this is a very popular recreational 

destination. 

The bottom habitat changes dramatically at the shelf break, 

where the offshore slope steepens (slope = 12-20°) between 

about 12 and 15 m water depth. The shelf break habitat here 

is characterized by scattered rocks and boulders, with two 

areas that lack significant rocks off Noio Point. The habitat 

is colonized with generally less than 50 percent coral cover 

of primarily P. lobata. Coral cover increases to moderately 

high (50 to <90 percent) on the northeast-southwest-trending 

section of the shelf break between Noio Point and the harbor. 

156°2' W 156°1'50'' 156°1'40"

19°39'50"

19°40' N

Meters

0 250

20

10

30

Alula

Bay

Noio Point

Honoko

–hau

Middle

Honoko

–hau

Inside

Honoko

–hau

Outside

Shoreline/intertidal

Shallow cliff

Shallow bench–narrow

Shallow bench–broad

Intermediate bench

Shelf break

Shelf escarpment

Deep slope

No bathymetric data

Profile

Isobath, interval 5 m

Mooring buoys 

South bench/escarpment

Habitat zones

G

Figure 52. Habitat zones of the south bench/escarpment region of KAHO overlaid on shaded relief bathymetry. Hatched lines 

indicate areas lacking bathymetric data. Line G shows the location of the cross-shelf profile shown in figure 54.
Results 49

High coral cover (90 to 100 percent) on aggregate reef exists 

on the easternmost end of the shelf break, where it meets the 

intermediate bench of the harbor embayment region. 

The shelf escarpment habitat begins in about 15 m of 

water and continues to water depths greater than 40 m. The 

slope here generally exceeds 20° (mean 28°) and reaches 

as high as 43°. Between about 15-m and 20-m depth, the 

sea floor is covered with scattered rocks and boulders with 

abundant P. compressa rubble. The percent of live coral 

cover in this region is typically low (10 to <50 percent) of 

predominantly P. lobata on dead P. compressa framework and 

rubble. In places, however, coral cover approaches 50 percent 

or greater total live cover.

In deeper water, the scattered rocks and boulder habitat 

transitions to a very dense, nearly continuous sheet of dead 

P. compressa framework and rubble with variable amounts 

of live coral cover. This habitat is persistent throughout the 

south bench region between about 20-m and 27-m depth, 

where the slope exceeds about 30°. Overall coral cover and 

in-place P. compressa is higher (>50 percent) in the relatively 

protected embayment offshore and to the north of Noio Point. 

In places the skeletal P. compressa framework looks relatively 

undisturbed from its natural growth form and was once likely 

a thriving reef habitat. Because this habitat is in such deep 

water and on a steep slope, it is very difficult to image using 

underwater video; thus, it is difficult to accurately estimate the 

percentage of live versus dead coral. One dive transect line 

near this area, however, shows some live coral (P. compressa

and P. lobata) at 85-ft (26-m) water depth. 

Below this band of nearly continuous P. compressa

rubble are scattered rocks, boulders, and rubble on volcanic 

pavement. This habitat is mostly uncolonized, although 

isolated coral colonies were observed. The depth of the 

deepest substantial coral coverage (>10 percent) in this region 

is between 27-m and 30-m depth, and the landward boundary 

of the habitat is placed along the 27-m depth contour. It is 

156°2' W 156°1'50'' 156°1'40"

19°39'50"

19°40' N

Meters

0 250

Alula

Bay

Noio Point

Honoko

–hau

Middle

Honoko

–hau

Inside

Honoko

–hau

Outside

South bench/excarpment

Habitat zones

Sand, uncolonized

Aggregate reef, 50–<90% coral

Aggregate reef, 90–100% coral

Volcanic pavement w/10–50% rocks/boulders, uncolonized

Volcanic pavement w/10–50% rocks/boulders, 10–<50% coral

Volcanic pavement w/10–50% rocks/boulders, 50–<90% coral

Volcanic pavement, uncolonized

Volcanic pavement, 10–<50% coral

Volcanic pavement, 50–<90% coral

Volcanic pavement, 90–100% coral

Volcanic pavement w/>50% rocks/boulders, uncolonized

Volcanic pavement w/>50% rocks/boulders, 10–<50% coral

Volcanic pavement w/>50% rocks/boulders, 50–<90% coral

Volcanic pavement w/ sand channels, 10–<50% coral

Volcanic pavement w/ sand channels, 90–100% coral

Reef rubble, 10–<50% coral

Reef rubble, 50–<90% coral

Other, artificial/historical

No bathymetric data

Profile location

Isobath, interval 5 m

Mooring buoys

20

10

30

G

Figure 53. Benthic habitat classifications of the south bench/

escarpment region of KAHO overlaid on shaded relief 

bathymetry. Some of the highest coral cover and the only 

area of aggregate reef mapped within the park are outlined 

with a white dashed box. Hatched lines indicate areas 

lacking bathymetric data. Line G shows the location of the 

cross-shelf profile shown in figure 54.
50 Kaloko-Honok–

ohau National Historical Park, Hawai`i

G. South Bench

Distance offshore (m)

Depth (m)

200 150 100 50 0 -50

Shoreline cliff

Intermediate bench

Shelf escarpment

Shelf break

Low coral on scattered rocks and Vpave

(P.lobata)

Uncolonized

 Vpave and rocks

Low-Uncolonized rubble and Vpave

(P. compressa)

Low-moderate coral on boulders

(P. meandrina; P.lobata)

40

30

20

10

0

-10

W E

Figure 54. Cross-shelf profile (G) and typical benthic habitat transitions of the south bench/

escarpment region of KAHO. Vpave = Volcanic Pavement. Vertical exaggeration is x2.

Figure 55. Three-dimensional perspective view of the south bench/escarpment region of KAHO, showing benthic habitat classifications 

draped on lidar bathymetry. The colors are the same as in figure 53. The red line is the shoreline, and the black line is the 20-m isobath. 

Habitat classifications are only displayed where lidar data exist. Vertical exaggeration is x3. View is toward the south. Approximate 

distance along the bottom of the figure is 0.4 km.
Discussion 51

unclear how deep this uncolonized scattered rock and rubble 

habitat extends, as no base of the slope, sand sheet, or deep 

slope habitat was observed in this area. The one fathometer 

transect collected within this area shows a decrease in offshore 

slope in about 60 m of water (fig. 26).

Discussion

Coral Zonation and Importance of Natural 

Disturbances on Coral Habitat

Coral communities in Kaloko-Honokōhau NHP (KAHO) 

generally follow the physiographic zonation of the Kona coast 

described by Dollar (1982) and Dollar and Tribble (1993), 

where a shallow boulder zone colonized primarily with P. 

meandrina transitions to a deeper reef bench zone dominated 

by P. lobata, followed by a reef slope zone colonized primarily 

by P. compressa, and finally a largely dead coral-rubble 

zone below depths of about 30 m (fig. 56). Within KAHO, a 

shallow bench zone with no boulders and an area of pinnacles 

and ridges also exist.

The well-defined zonation of the coral community 

structure is likely a result of variable importance of wave 

stresses on the coral from breaking waves (Dollar, 1982). 

Our results show variability within this model across KAHO, 

reflecting differences in wave stresses and possibly other 

controls (for example, groundwater, recreation, harbor 

development). In the shallow bench and boulder zones, 

turbulence and high shear stresses resulting from approaching 

and reflected waves prevent colonization by fragile corals, 

and the resulting community structure is dominated by robust 

species such as the short, dense P. meandrina and encrusting 

P. lobata. Small (< 0.2-m diameter) isolated colonies of P. 

lobata in these environments indicate frequent disturbance. 

In the deeper, steep-sloped shelf escarpment region, where 

wave energy is normally low, the habitat is generally 

dominated by monospecific thickets of the relatively fragile 

but competitively superior species, P. compressa. Below 

about 30-m water depth, reduced light levels, and perhaps 

loose and mobile rubble and rock, limit coral growth and only 

scattered, small colonies of primarily P. lobata grow on the 

boulders, rubble fragments, or volcanic pavement. The highest 

percentage and diversity of coral speciation are between these 

extremes, at intermediate water depths where wave stresses 

are high enough to prevent monopolization by competitive 

species like P. compressa and low enough to enable settlement 

and growth of many different coral species. 

While the zonation and community structure transitions 

described above are evident in KAHO, the sea-floor 

morphology in the park is more complex than along much 

of the Kona coast. The mid-shelf cliffs, the semiprotected 

environments provided by the pinnacles off Kaloko Fishpond 

and Kaloko Point, and the embayed form of the coast support 

localized coral ecosystems that are unique to the KAHO region. 

The coral cover in the park is low overall, except 

for areas that are relatively protected from high wave 

energy—in the most deeply embayed reaches off the harbor 

mouth and off Kaloko Fishpond. In both of these areas, the 

coral communities are diverse, healthy, and thriving. The 

embayments are locally protected from south swell and Kona 

storms by Noio Point and from all but the most westerly north 

Pacific swell by Wawahiwa`a Point. Between the two, the 

deep bench and central bench/escarpment regions provide 

additional protection from larger waves that shoal across the 

relatively exposed platforms. 

In the deeper water of the shelf escarpment habitat, 

where wave stresses are reduced, dense coral thickets of P. 

compressa framework exist, although many appear to be dead 

and covered with coralline algae and octocoral; live coral 

growth is typically limited to the ends of the fingers. Most 

of the thickets are interconnected and in growth form, rather 

than disconnected pieces of scattered rubble, suggesting that 

this was perhaps once a thriving coral habitat, or alternatively, 

is a slowly growing community struggling to survive. It is 

Figure 56. Schematic diagram 

of the physiographic zonation 

of coral communities along the 

Kona coast of Hawai`i (Dollar and 

Tribble, 1993).
52 Kaloko-Honok–

ohau National Historical Park, Hawai`i

likely that this habitat is significantly stressed by wave scour 

associated with large storms that are not infrequent along the 

southern Kona coast (Dollar,1982; Dollar and Tribble,1993). 

Although P. compressa is one of the most rapidly growing and 

opportunistic species in the Hawaiian Islands, the relatively 

low light and steepness over the shelf escarpment may restrict 

or limit its ability to recover and thrive.

The lack of vertical accretion of carbonate material 

and aggregate reef growth along the Kona coast is unusual 

compared to the rest of the Hawaiian Islands. This deficiency 

is likely due to a combination of the geologically young 

age of the surface upon which the corals grow (10–1.5 ka), 

combined with the episodic destruction of coral colonies 

by storms and transport of carbonate material downslope. 

Lithification, cementation, and accretion can occur only in 

places that are relatively protected from waves. Processes 

that limit reef accretion in other coral-reef habitats, such 

as predation (for example, by Acanthaster planci), loss of 

accommodation space (Great Barrier Reef), temperature 

fluctuations, sedimentation, and disease, appear to not be 

limiting factors along the Kona coast. 

Status of the Habitat

Overall, the park’s offshore region supports a healthy 

and relatively diverse coral habitat. Little evidence of invasive 

macroalgae and no diseased coral were observed. Limited 

occurrences of macroalgae were, however, noted (fig. 57). 

Several of the potentially destructive sea star Acanthaster 

planci were observed, although limited evidence for 

widespread destruction of coral suggests that these predators 

may be balanced within the ecosystem. 

The low diversity, low overall coral cover, and 

deteriorated habitat in the slope escarpment zones suggest that 

the coral ecosystem in the park may be adjusting to stormrelated damage over the last few decades. This is different 

from other stressed regions in the islands (for example, 

Kāne`ohe Bay and Māmala Bay on O`ahu and West Maui and 

Kīhei on Maui), where stresses on the corals are a combination 

of high sedimentation, nutrification, overfishing, and other 

anthropogenic stresses. 

Sediment delivery is low along the Kona coast because 

of the relatively young geologic age of the adjacent volcanoes, 

poor soil development, and low annual rainfall. Few coastal 

streams exist along the Kona coast, and none are found within 

or adjacent to Kaloko-Honokōhau NHP. Thus, low sedimentation rates, along with the dearth of invasive or native 

macroalgae and thriving, healthy reefs in protected locations 

suggest that the coral habitat in KAHO is primarily controlled 

by natural wave-induced stresses, with little evidence of 

anthropogenic stresses. Areas of high visitor use, such as near 

the shoreline or around mooring buoys, were not specifically 

evaluated for impacts of the users.

The only anomalous area appears to be off the harbor 

mouth, where an area of low coral cover was mapped between 

some of the highest and most diverse coral communities 

within the study area (fig. 48). The causes of this apparent 

degradation are unclear and may warrant further investigation. 

Possible explanations may be related to the proximity of 

the harbor, such as increased sedimentation, increased wave 

stresses associated with the passage of boats, and water quality 

differences, including variations in salinity, temperature, 

and/or water chemistry. Coral surveys conducted outside the 

harbor in 1971, 1976, and 1981 revealed no substantial trends 

or changes in coral cover after harbor construction (Maragos, 

1983), although changes in water quality were observed 

after the expansion of the harbor in 1979 (U.S. Army Corps 

of Engineers, 1983). No dredging or deposition of material 

from the harbor has occurred since initial harbor construction 

(Nancy Murphy, written commun., 2006).

An alternative hypothesis is that the degraded area, 

located at the apex of the embayment, may be a natural 

channel or pathway for water flow onto and off the shallower 

platforms. If this is true, locally higher bottom stresses 

associated with this water movement may limit the growth of 

coral that thrives in the adjacent environments. Measurements 

of currents, waves, and water quality and long-term habitat 

monitoring transects are needed to determine the influence of 

the harbor on this area of apparent coral degradation. 

Ages of Submerged Volcanics and Sea-Level 

History

The complex structure of the sea floor in the study area 

results from the deposition of multiple volcanic flows and 

their subsequent erosion over thousands of years. Although 

three distinct volcanic flows are exposed within the emergent 

portion of KAHO, the age of the submerged flows and their 

depositional relationship to the emergent flows is poorly 

constrained. The delineation of volcanic flows on land is 

typically achieved using visual clues from photographic or 

satellite imagery in combination with radiometric age dating 

and the geological and morphological relationships between the 

volcanic deposits. Underwater, the visual and morphological 

relationships are obscured by sediment deposition, biological 

growth, and physical erosion of the deposits, which make 

delineation of individual flows problematic. In many places 

(for example, central bench/escarpment and pinnacles regions), 

the surface of the volcanic pavement shows textures commonly 

seen on exposed flows (ropey pahoehoe, pinnacles, and tubes), 

suggesting that little erosion has occurred in these locations. 

However, the presence of the shallow and deep cliffs and the 

abundant, well-rounded boulders that cover much of the study 

area indicates that extensive erosion has been modifying the 

shape of the sea floor over an extended period of time. No 

features or morphology that would indicate primary deposition 

underwater (for example, lava pillows) were observed, 

suggesting that the flows we observe today were originally 

deposited subaerially and have subsided to their present 

position below sea level.
Discussion 53

No radiometric age dates have been acquired for the 

volcanic substrate of offshore KAHO. This information is 

essential in order to definitively determine the ages of and 

relations between the submerged and emergent flows. The 

only area for which an age can be assigned with some level of 

confidence is the shallow narrow platform north of the central 

bench/escarpment region, where it appears to be a flooded 

surface that is topographically continuous with the shoreline 

and upland area mapped as the 5-3 ka volcanic flow by Wolfe 

and Morris (1996).

The relationship of the submerged flows to the emergent 

flows is further complicated by the sea-level and submergence 

histories of the island—each of which is poorly constrained. 

Historical measurements from a tide gauge in Hilo, on the 

east coast of Hawai`i, provide the best estimates of modern 

rates of relative sea-level change and island subsidence. These 

estimates, however, should be used with the caveat that the 

rates may not be linear and likely vary largely over time. 

Because of the proximity of the tide gauge to KAHO and the 

complexity of the geologic structure of the Island of Hawai`i, 

the rates recorded at Hilo during the modern era may not 

accurately reflect subsidence rates on the Kona coast over the 

time period of analysis. Estimates of the relative role of global 

eustatic sea-level rise in the Hawaiian Islands can be made 

using data from Grossman and Fletcher (1998).

On the basis of the present rate of local relative sea-level 

rise of 3.13 ± 0.30 mm/yr as measured at Hilo (1947-2003; 

Permanent Service for Mean Sea Level, 2006) and the eustatic 

positions calculated for the Hawaiian Islands by Grossman and 

Fletcher (1998), the elevation of the shoreline at time periods 

corresponding to the bounding ages of the lava flows within 

KAHO is summarized in table 7. 

Figure 57. Photographs showing examples of the limited macroalgae and sea-stars observed in the study area. 

A, Brown macroalgae and turf algae in the deep slope habitat in the pinnacles region, depth 23 m. B, Green 

macroalgae on shelf escarpment in central bench/escarpment region, depth 23 m. C, Anthelia edmonsoni and 

brown turf algae on shallow bench in central bench/escarpment region; depth 1 m. D, Crown-of-thorns sea star 

Acanthaster planci on intermediate bench in pinnacles region; depth 8 m. 
54 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Unique Underwater Features 

Numerous unique and interesting geological features 

are present in the offshore regions of KAHO. Many large 

pinnacles and arches are present between Kaloko Fishpond 

and Kaloko Point. Most appear to be depositional in origin 

and may have formed as lava tubes during original flow 

emplacement (fig. 58A). The vertical relief and coral cover on 

these pinnacles attract numerous fish species, and these may 

therefore be areas with potential archeological significance 

with respect to ancient fishing grounds. 

Potholes observed on the outer edge of the shallow 

central platform were likely formed by the swirling action 

of sediment on the volcanic pavement surface, but may also 

have archeological significance (fig. 58B). On the basis of the 

island subsidence rates discussed above, the location of these 

potholes, along with the entire shallow bench, would have 

been exposed around 1.5 ka.

Caves located along the shallow cliff in the northern 

bench/escarpment area provide a unique environment for scuba 

activities and have the potential to be conduits for freshwater 

influx to marine waters. Studies in progress by the USGS 

(Grossman and others, 2006) aim to characterize the flux, 

pathways, and fate of ground water and associated nutrients and 

contaminants discharging into the nearshore waters of the park 

from these caves, the harbor mouth, and other sites.

Although rare in other parts of the Hawaiian Islands, 

the lavender-hued octocoral Anthelia edmonsoni is abundant 

in the shallows of the central bench/escarpment area, but it 

Figure 58. Photographs showing examples of some unique underwater features and organisms observed in the 

study area. A, Lava tubes (?) off Kaloko Point. B, Pothole (arrow) in basalt at the edge of the shallow bench in the 

central region. C, The lavender-hued octocoral Anthelia edmonsoni. D, A manta ray—one of the many pelagic 

species to inhabit the park.

Table 7. Relative sea-level position, estimated subsidence 

amounts, and depth of the shoreline for the ages bounding the 

lava flows present in Kaloko-Honoko–hau National Historical Park 

(KAHO).

Age of 

flow

(yr B.P)

Sea-level position 

relative to 

present1

 (m)

Subsidence2

(m)

Depth of 

shoreline at 

time = t (m)

1,500 +0.5 4.7 -4.2

3,000 +2.0 9.4 -7.4

5,000 +0.5 15.6 -15.1

10,000 -25.0 31.3 -56.3

1

From Grossman and Fletcher (1998); 2 3.13 mm/yr x years
Discussion 55

is present as part of the colonizing coral community in many 

other locations as well (fig. 58C) . It is fairly common along the 

Kona coast and is thought to be an indicator of freshwater input 

(Brock and Brock, 1974; Parrish and others, 1990).

The relatively narrow shelf and steep offshore slope fronting 

most of the study area is also unusual compared to other locations 

in Hawai`i; it allows the close approach of large pelagic species 

such as manta rays, sharks, and whales (fig. 58D). 

A final interesting underwater feature, or lack thereof in this 

case, is the relative dearth of the coral species Montipora capitata. 

This coral species is widely found within the Hawaiian island 

chain, but restricted to vertical walls and small colonies on the reef 

within KAHO and along the Kona coast in general. 

No archeological features were identified, aside from the 

remnants of building structures and fishpond walls close to shore.

Accuracy of Maps

A total of 187 points were checked in the field by thirdparty investigators familiar with the NOAA habitat mapping 

classification scheme. There was some confusion regarding 

the added classes (octocoral, volcanic pavement with rocks 

and boulders) that may have resulted in some incorrect 

scoring of the evaluated polygons, but the overall accuracy 

assessments were good to very good. 

Table 8 shows the matrix of accuracy assessment 

calculations for the major biological covers. Two points 

were deleted from the final accuracy assessment calculation 

for this class due to observer variation in the determination 

of coral cover (Will Smith, written commun.). The overall 

accuracy of 90.3 percent (with a 95-percent confidence interval 

of ± 1.3) indicates which points on the map were classified 

correctly according to the field check. A tau coefficient (Ma 

and Redmond, 1995) of 0.878 indicates that 87.8 percent more 

points are classified correctly than would be expected by chance 

alone. 

Table 9 shows the matrix of accuracy assessment 

calculations for the dominant structure. A total of 187 points 

were checked in the field. The overall accuracy of 73.3 percent 

(with a 95-percent confidence interval of ± 1.3) indicates 

which points on the map were classified correctly according 

to the field check. A tau coefficient (Ma and Redmond, 1995) 

of 0.708 indicates that 70.8 percent more points are classified 

correctly than would be expected by chance alone.

Table 10 shows the matrix of accuracy assessment 

calculations for the percent cover. A total of 185 points were 

checked in the field. The overall accuracy of 71.4 percent 

(with a 95-percent confidence interval of ± 1.3) indicates 

which points on the map were classified correctly according 

to the field check. A tau coefficient (Ma and Redmond, 1995) 

of 0.690 indicates that 69.0 percent more points are classified 

correctly than would be expected by chance alone.

After accuracy assessment calculations were performed, 

any misinterpreted polygons identified on the map were 

corrected using the field check data, thus increasing the 

accuracy of the final map.

Special Considerations and Recommendations 

for Future Work

As results of the study reported in this work, the 

following observations and recommendations are given:

• The areas of highest coral cover within the park 

are located adjacent to the most highly developed 

(or developing) areas of adjacent coast – offshore 

Honokōhau Harbor and Kaloko Fishpond. We 

recommend that the National Park Service establish 

long-term monitoring stations near these locations 

to evaluate any changes in environmental conditions 

(sedimentation, water quality, direct impact) that may 

adversely affect the habitats in the future.

• Establish coral and water-quality monitoring and 

current measurement transects near the poorly 

colonized area off the harbor mouth and control area(s) 

in order to determine whether potential changes in 

Table 8. Accuracy assessment matrix for the major biological cover classes.

Found to be in field

Total User’s

Coral Accuracy

MacroalgaeOctocoralEmergent 

Vegetation

Uncolonized

As mapped

Coral 134 0 1 0 6 141 95%

Macroalgae 0 0 0 0 0 3

Octocoral 0 1 3 0 1 5 60%

Emergent Vegetation 0 0 0 0 0 0

Uncolonized 6 0 0 0 30 36 83%

Total 140 1 4 0 40

Producer’s Accuracy 96% 0% 75% 75% 185

Diagonal Sum

=167

Overall Accuracy

=90.3%
56 Kaloko-Honok–

ohau National Historical Park, Hawai`i

sedimentation, water quality, or bottom currents are 

affecting coral colonization off the harbor mouth. 

• Define boundaries of the degraded area off the harbor 

mouth to evaluate its stability, the processes affecting 

it, and/or to determine if the adjacent areas of thriving 

coral habitat are expanding, contracting, or susceptible 

to these same processes.

• Evaluate freshwater conduits and establish water-quality and benthic-habitat monitoring locations along the 

north boundary of the park, off Kohanaiki, near areas 

of recent and future development of housing and golf 

courses.

• Establish additional scuba transects to better quantify 

spatial variations in the percent cover, health of P. compressa, and structure of the shelf-escarpment habitat.

• Establish long-term coral and fish monitoring sites to 

monitor coral health and ecosystem health throughout 

the park.

• Collect airborne infrared or hyperspectral imagery to 

isolate spectrally unique bio-indicators to improve 

delineation of intertidal habitats.

Acknowledgements

This project was funded by the U.S. Geological Survey 

(Coral Reef Project, Coastal and Marine Geology Program) 

and by the National Park Service (Kaloko-Honokōhau NHP). 

The authors thank Pat Chavez and his group from the USGS 

in Flagstaff for coordinating our acquisition of the SHOALS 

bathymetric data. Ku`ulei Rodgers and colleagues from the 

University of Hawai`i Coral Reef Assessment and Monitoring 

Program (CRAMP) team collected the rapid assessment 

Table 9. Accuracy assessment matrix for the percent of major biologic cover classes.

Found to be in field

10-<50% Coral50-<90% Coral90-100% Coral10-<50% Macroalgae50-<90% Macroalgae90-100% Macroalgae10-<50% Octocoral50-<90% Octocoral90-100% Octocoral10-<50% Emergent Veg.50-<90% Emergent Veg.90-100% Emergent Veg.Uncolonized

TotalUser’s Accuracy

As mapped

10-<50% Coral 72 3 0 0 0 0 1 0 0 0 0 0 5 81 89%

50-<90% Coral 18 20 1 0 0 0 0 0 0 0 0 0 1 40 50%

90-100% Coral 3 9 8 0 0 0 0 0 0 0 0 0 0 20 40%

10-<50% Macroalgae 0 0 0 0 0 0 0 0 0 0 0 0 0 0

50-<90% Macroalgae 0 0 0 0 0 0 0 0 0 0 0 0 3 3

90-100% Macroalgae 0 0 0 0 0 0 0 0 0 0 0 0 0 0

10-<50% Octocoral 0 0 0 0 0 0 0 0 0 0 0 0 0 0

50-<90% Octocoral 0 0 0 0 0 0 0 2 1 0 0 0 2 5 40%

90-100% Octocoral 0 0 0 0 0 0 0 0 0 0 0 0 0 0

10-<50% Emergent Veg. 0 0 0 0 0 0 0 0 0 0 0 0 0 0

50-<90% Emergent Veg. 0 0 0 0 0 0 0 0 0 0 0 0 0 0

90-100% Emergent Veg. 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Uncolonized 6 0 0 0 0 0 0 0 0 0 0 0 30 36 83%

Total 99 32 9 0 0 0 1 2 1 0 0 0 41 185

Producer’s Accuracy 73% 63% 89% 0% 100% 0% 75% 185

Diagonal 

sum = 

132

Overall 

Accuracy

 = 71.4%
References Cited 57

data referred to in this document. Will Smith and other 

CRAMP team members performed the third-party fieldcheck observations and provided the accuracy assessment 

calculations. Sallie Beavers from Kaloko-Honokōhau NHP 

supplied us with the smaller boats (Boston Whaler and kayaks) 

and assisted with logistics while we were on island. Lisa 

Marrack (NPS), Sallie Beavers (NPS), Jane Reid (USGS), and 

Mike Field (USGS) provided very helpful reviews of early 

drafts of the report. A special mahalo goes to Captain Joe 

Reich, owner of the Alyce C on Moloka`i, whose exceptional 

navigation and local expertise were critical to the success of 

this project.

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Table 10. Accuracy assessment matrix for the dominant structure classes.

Found to be in field

 Aggregate Reef Aggregate Patch Reef Individual Patch Reef Spur-and-Groove Volcanic Pavement VolPv w/Sand Chnls VolPv w/ 10-50% Rx/Bldr VolPv w/ >50% Rx/Bldr Rubble Sand Mud Land Total User’s Accuracy

As mapped

Aggregate Reef 3 0 0 0 1 0 0 0 0 0 0 0 4 75%

Aggregate Patch Reef 0 0 0 0 0 0 0 0 0 0 0 0 0

Individual Patch Reef 0 0 0 0 0 0 0 0 0 0 0 0 0

Spur-and-Groove 0 0 0 0 0 0 0 0 0 0 0 0 0

Volcanic Pavement 1 0 0 0 56 2 3 2 0 0 0 0 64 88%

VolPv w/Sand Channels 0 0 0 0 7 14 4 3 0 1 0 0 29 48%

VolPv w/ 10-50% Rx/Bldr 0 0 0 0 3 1 19 3 0 2 0 0 28 68%

VolPv w/ >50% Rx/Bldr 1 0 0 0 3 2 8 22 0 0 0 0 36 61%

Rubble 0 0 0 0 0 0 0 0 0 0 0 0 0

Sand 0 0 0 0 3 0 0 0 0 23 0 0 26 88%

Mud 0 0 0 0 0 0 0 0 0 0 0 0 0

Land 0 0 0 0 0 0 0 0 0 0 0 0 0

Total 5 0 0 0 73 19 34 30 0 26 0 0 187

Producer’s Accuracy 60% 77% 74% 56% 73% 88% 187

Diagonal 

sum = 

137

Overall 

Accuracy

 = 73.3%
58 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Greene, L.W., 1993, A cultural history of three traditional 

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development where wave energy reduces accommodation 

space, Kailua Bay, Windward Oahu, Hawaii, U.S.A.: Journal of Sedimentary Research, v. 74, no. 1, p. 49–63.

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Street, J., 2006, Mapping groundwater discharge and nutrient flux across the fringing reefs of south Moloka’i and west 

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resources and watershed conditions in Kaloko-Honokohau 

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and Monaco, M.E., 2004, The seascape approach to coral 

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ecological studies following construction of the Honokohau small boat harbor, Kona, Hawai`i: U.S. Army Corps of 

Engineers, p. 32–59.

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systems: Honolulu, Hawai`i Institute of Geophysics, University of Hawaii, 95 p.

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noaa.gov/products/biogeography/us_pac_terr/].

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[http://tidesandcurrents/tides05/tab2wc3.html].

Parrish, J.D., Smith, G.C., and Norris, J.E., 1990, Resources of 

the marine waters of Kaloko-Honokōhau National Historical Park: Cooperative National Park Resource Studies Unit, 

Technical Report 74, 115 p.

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secular trends: Liverpool, UK, [http://www.pol.ac.uk/psmsl/

datainfo/rlr.trends].

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assessment of Kaloko/Honokōhau and Pu’uhonua o 

Honaunau, West Hawai`i: Hawai`i Coral Reef Assessment 

and Monitoring Program (CRAMP), Hawai`i Institute of 

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Florida’s shallow-water coral ecosystems; an implementation plan: National Oceanic and Atmospheric Administration Technical Memorandum NOS NCCOS 19, 39 p.,

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Appendix 59

Appendix 

Detailed Classification Scheme

The following describes the classification scheme used 

by the U.S. Geological Survey for benthic habitat mapping 

of National Parks on the Kona Coast of Hawai`i. Each of the 

habitats and zones is described in detail with some example 

photos. Many of the descriptions are from NOAA’s classification scheme for the main eight Hawaiian Islands (Coyne 

and others, 2003), and subsequent revision (National Oceanic 

and Atmospheric Administration National Centers for Coastal 

Ocean Science, 2005).

Habitats

Major Structure—Unconsolidated Sediment

Mud Fine sediment often associated with stream discharge 

and buildup of organic material in areas sheltered from highenergy waves and currents (for example, harbors, fishponds).

Major Structure—Reef and Hardbottom

Aggregate reef Formations with high relief and complexity, 

which form an extensive reef structure without sand channels 

(as found in spur-and-groove). Note that aggregate reef refers 

to the underlying hard structure and implies nothing about the 

nature of the biological cover, nor whether it is live or dead. 

Sand Coarse sediment typically found in areas exposed to 

currents or high wave energy (reef-derived) or on beaches 

(land-derived or reef-derived).

Spur-and-groove Elongate, alternating sand and coral formations that are oriented perpendicular to the shore or bank/

shelf escarpment. The coral formations (spurs) of this feature 

typically have a high vertical relief relative to the pavement 

with the channels, and are separated from each other by 1–5 

Example of muddy shallow area exposed at low tide. meters of sand or bare pavement (grooves).

(Kawela, Moloka`i) 

Example of aggregate reef with 90–100 percent coral. 

(Kawaihae Bay, Hawai`i)

Example of uncolonized sand. (Kaloko-Hon–okohau, Hawai`i)

Example of spur-and-groove reef system with 90–100 percent 

coral cover on the spurs. (Kawaihae Bay, Hawai`i)
60 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Individual patch reef Coral formations, larger than or equal 

to the MMU (100 m2 in this study), that are isolated from other 

coral reef formations by sand, seagrass, or other habitats and 

that have no organized structural axis relative to the contours 

of the shore or shelf edge. 

Aggregated patch reefs Clustered coral formations, smaller 

than the MMU (100 m2 in this study) or too close together to 

be mapped separately, that are isolated from other coral reef 

formations by sand, seagrass, or other habitats and that have 

no organized structural axis relative to the contours of the 

shore or shelf edge.

Volcanic pavement with sand channels Having volcanic substrate alternating with sand channels that are oriented perpendicular to the shore or bank/shelf escarpment. The sand channels 

have low vertical relief relative to spur-and-groove formations.

Volcanic pavement Volcanic substrate with less than 10 percent loose rocks or boulders scattered on the surface. May be 

smooth or irregular, depending on the original lava flow and 

subsequent erosion patterns.

Example of volcanic pavement with 50–<90 percent coral cover. 

(H–onaunau Bay, Hawai`i)

Example of volcanic pavement with sand channels, with 90– 100 

percent coral cover. (Kaloko-Honok–ohau, Hawai`i)

Example of aggregated patch reefs covered with 50–<90 percent 

coral. These patch reefs are smaller than the minimum mapping 

unit and so could not be called individual patch reefs. They 

would be digitized together, along with the others shown in the 

background, as aggregated patch reefs. (Moloka`i)

Volcanic pavement with 10–50 percent rocks/boulders 

Volcanic substrate with 10–50 percent volcanic rocks and/

or boulders scattered on the surface. The underlying substrate 

may be smooth or irregular, depending on the original lava 

flow and subsequent erosion patterns.

Example of volcanic pavement with 10–50 percent rocks/boulders,

with 10–50 percent coral cover. (H–onaunau Bay, Hawai`i)
Appendix 61

Major Structure—Other 

Land Area shoreward of the mean high water line, or landward edge of emergent vegetation, when present.

Artificial Manmade habitats such as large piers, submerged 

parts of riprap jetties, and shoreline areas created from dredge 

spoil.

Artificial/historical Manmade features of historical significance, such as active and relict fishpond walls.

Zones

Land Area shoreward of the mean high water line, or landward edge of emergent vegetation, when present.

Shoreline/intertidal Area between the mean high water line 

(or landward edge of emergent vegetation) and lowest spring 

tide level. Typical habitats include mangrove and other emergent vegetation, sand, mud, and uncolonized rock.

Vertical wall Area with near-vertical slope along channels, 

from shelf to shelf escarpment, or between different innershelf platforms. This zone is typically narrow and may not be 

visible in remotely sensed imagery, but is included because 

it is recognized as a biologically important feature. Typical 

habitats include coral, algae, and uncolonized rock.

Lagoon The shallow area between the shoreline/intertidal 

zone and the back reef zone of a barrier reef system. If no 

reef crest is present, there is no lagoon zone. Typical habitats 

include individual patch reefs, sand, seagrass, algae, and pavement. (Not typically used for the Kona Coast.)

Back reef (with lagoon) Area between the seaward edge of a 

lagoon floor and the landward edge of a reef crest. This zone 

is only present when a reef crest and lagoon exist. Typical 

habitats include sand, coral rubble, seagrass, algae, and patch 

reefs. (Not typically used for the Kona Coast.)

Reef flat (without lagoon) Shallow, semiexposed area 

between the shoreline/intertidal zone and the reef crest of a 

fringing reef system. This zone is protected from the high-energy waves commonly experienced on the reef crest and fore 

reef. The reef flat is not present if there is a lagoon. Typical 

habitats include sand, rubble, pavement, algae, mud, and patch 

reefs.

Reef crest The flattened, emergent (especially during low 

tides) or nearly emergent segment of a reef, usually where the 

waves break. This zone lies between the back reef and fore 

reef zones of a barrier reef system, and between the reef flat 

and fore reef of a fringing system. Typical habitats include reef 

rubble, patch reefs, and aggregate reefs.

Volcanic pavement with >50 percent rocks/boulders Volcanic substrate with >50 percent volcanic rock and/or boulders 

on the surface. The underlying substrate may be smooth or 

irregular, depending on the original lava flow and subsequent 

erosion patterns.

Example of volcanic pavement with >50 percent rocks/boulders 

with <10 percent cover, therefore 90–100 percent uncolonized. 

(Kaloko-Honok–ohau, Hawai`i)

Reef rubble Dead, unstable coral rubble, often covered with 

coralline algae or filamentous or other macroalgae.

Example of reef rubble with <10 percent cover, therefore 90–100 

percent uncolonized. (Kawaihae Bay, Hawai`i)
62 Kaloko-Honok–

ohau National Historical Park, Hawai`i

Fore reef Area from the seaward edge of the reef crest that 

slopes into deeper water to the landward edge of the bank/

shelf platform. Also defined as fore reef are features not forming an emergent reef crest but still having a seaward-facing 

slope that is significantly greater than the slope of the bank/

shelf. Typical habitats include aggregate coral reef and spurand-groove.

Bank/shelf A deep-water platform extending offshore 

from the seaward edge of the fore reef to the beginning of 

the escarpment where the insular shelf drops off into deep, 

oceanic water. If no reef crest is present, the bank/shelf is the 

flattened platform between the shoreline/intertidal zone and 

deeper ocean offshore. Typical habitats include sand, patch 

reefs, algae, colonized and uncolonized pavement with and 

without sand channels, and other coral habitats.

Bank/shelf escarpment The edge of the bank/shelf where 

depth increases rapidly into deep, oceanic water. This zone 

begins at approximately 20 to 30 meters depth, near the depth 

limit of features visible in aerial images. This zone captures 

the transition from the shelf to deep oceanic waters. Typical 

habitats include sand, aggregate reef, and spur-and-groove.

Channel Naturally occurring channels that often cut across 

several other zones. Typical habitats include sand, mud, and 

uncolonized pavement.

Dredged Area in which natural geomorphology is disrupted 

by excavation or dredging (for example, harbors and manmade 

channels). Typical habitats include rubble, sand, and mud.

Unknown Zone uninterpretable because of turbidity, cloud 

cover, water depth, or other interference.