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

Geologic Resource Evaluation of

Pu`ukohola– Heiau National Historic Site, Hawai`i 

Part II: Benthic Habitat Mapping

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2006-5254
Geologic Resource Evaluation of

Pu`ukohol–a Heiau National Historic Site, Hawai`i

Part II: Benthic Habitat Mapping

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

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

Scientific Investigations Report 2006–5254 

U.S. Department of the Interior

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

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

U.S. Geological Survey, Reston, Virginia: 2007

This report and any updates to it are available at: http://pubs.usgs.gov/sir/2006/5254

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Manuscript approved for publication, September 28, 2006

Text edited by Peter H. Stauffer

Layout by David R. Jones

Suggested citation:

Cochran, S.A., Gibbs, A.E., and Logan, J.B., 2007, Geologic resource evaluation of Pu`ukohol–a Heiau National Historic 

Site, Hawai`i; Part II, Benthic habitat mapping: U.S. Geological Survey Scientific Investigations Report 2006-5254, 20 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.

Cover: Left, enlarged portion of benthic habitat map showing Pelekane Bay and Pu`ukohol–

a Heiau National Historic 

Site shoreline. Right, underwater photograph shows example of coral reef habitat on the Kona coast of Hawai`i.
iii

Contents

Introduction.....................................................................................................................................................1

Data and methods..........................................................................................................................................3

Background data...................................................................................................................................3

SHOALS bathymetry....................................................................................................................3

Aerial photography......................................................................................................................3

Acquired data........................................................................................................................................8

Underwater video and still photography .................................................................................8

Benthic habitat mapping using GIS ...................................................................................................9

Classification scheme.................................................................................................................9

Accuracy assessment .............................................................................................................10

Data archive.........................................................................................................................................10

Results

Kawaihae Bay......................................................................................................................................10

Pelekane Bay.......................................................................................................................................11

Accuracy of maps...............................................................................................................................14

Resource concerns ............................................................................................................................14

Acknowledgements.....................................................................................................................................14

References....................................................................................................................................................16

Appendix 

Detailed classification scheme .................................................................................................................17

Figures

1. Index map of the Island of Hawai`i showing the location of the three 

National Parks along the Kona coast .................................................................................................1

2. Aerial photomosaic showing PUHE park boundary, study area, watersheds, 

streams, and place names discussed in text ....................................................................................2

3. Flowchart illustrating methodology used to create Acquired Data habitat map ........................3

4. Aerial photomosaic of Kawaihae Bay overlaid with SHOALS bathymetry coverage. ...............4

5. Aerial photomosaic of Kawaihae Bay area showing PUHE park boundary and 

study area................................................................................................................................................5

6. Aerial photomosaic of Kawaihae Bay merged with shaded relief from SHOALS 

bathymetry...............................................................................................................................................6

7. Aerial photomosaic of northern Kawaihae Bay showing shaded relief, overlaid 

with locations of video transects and still photos. ...........................................................................7

8. Photograph of the Alyce C of Moloka`i heading out of M–a`alaea Harbor, Maui. ........................8

9. Photograph of SEAVIEWER camera system rigged to collect towed video. ...............................8

10. Photograph of shipboard system for navigation, recording of ship’s position, 

and feature annotation ..........................................................................................................................8

11. Schematic diagram showing the generalized cross-shelf coral reef zonation.........................10

12. Three-dimensional perspective view of area of study in Kawaihae Bay, 

showing geographic reef zonation....................................................................................................11
iv

13. Aerial photomosaic of Pu`ukohol–a Heiau National Historic Site, overlaid with 

benthic habitat map..............................................................................................................................12

14. Aerial image of northern Kawaihae Bay showing shaded relief and cross-section 

profiles of the reef ................................................................................................................................13

15. Pie chart showing the breakdown of dominant reef structures of the PUHE study area........13

16. Graph showing proportions of dominant structures with depth at PUHE ..................................14

17. Pie chart showing the breakdown of major biologic coverage in the PUHE study area .........14

18. Enlarged portion of the benthic habitat map showing Pelekane Bay and PUHE shoreline ....15

Tables

1. Major structure (substrate) types with dominant structure subdivisions. ...................................9

2. Major biologic cover classes. ..............................................................................................................9

3. Percent cover classes...........................................................................................................................9

4. Geomorphic zones of coral reef ecosystems ..................................................................................10

5. Matrix showing accuracy assessment for the major biological cover classes ........................15
Geologic Resource Evaluation of

Pu`ukohol–a Heiau National Historic Site, Hawai`i 

Part II: Benthic Habitat Mapping

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

the U.S. Coast Guard Reservation north of Kawaihae Harbor 

approximately 3.5 km south to the north edge of the Mauna 

Kea Golf Course and Beach Resort at Waikoloa and from the 

shoreline to depths of approximately 40 m (130 ft), where 

the fore reef drops off to the sandy shelf (fig. 2). The waters 

of smaller Pelekane Bay directly offshore of the park, while 

not formally under NPS jurisdiction, are managed by the 

park under an agreement with the State. This embayment is 

described in greater detail because of its special resource status.

PUHE lies within the Kawaihae watershed, which contributes ~75 percent of the drainage in the northern portion of 

the study area; the Waikoloa/Waiulaula watershed contributes 

~25 percent in the southern portion of the study area. Drainages from these watersheds into the study area include Makahuna, Makeähua, Pohaukole, Kukui, and Waikoloa/Waiulaula 

Gulches. The Waikoloa/Waiulaula Gulch is the only perennial 

Introduction

In cooperation with the U.S. National Park Service (NPS), 

the U.S. Geological Survey (USGS) has mapped the underwater environment in and adjacent to three parks along the Kona 

coast on the island of Hawai`i (fig. 1). This report is the second 

of two produced for the NPS on the geologic resource evaluation of Pu`ukoholä Heiau National Historic Site (PUHE) and 

presents benthic habitat mapping of the waters of Kawaihae 

Bay offshore of PUHE. See Part I (Richmond and others, 2008) 

for an overview of the regional geology, local volcanics, and a 

detailed description of coastal landforms in the park.

PUHE boundaries do not officially extend into the marine 

environment; however, impacts downslope of any activity in 

the park are of concern to management. The area of Kawaihae 

Bay mapped for this report extends from the north edge of 

Pacific

Ocean

Hawaiian Islands

MAP

AREA Hawai`i Hawai`i

20° N 

19°30'

19°

156° W 155°30' 155°

Kilometers

0 50

Pu`ukohol–a Heiau

National Historic Site

(PUHE)

Kaloko-Honok–ohau

National Historical Park

(KAHO)

Pu`uhonua H–

onaunau

National Historical Park

(PUHO)

Hilo

Kailua-Kona

Mauna Loa

Mauna Kea

Hualalai

Kohala

Figure 1. Index map of the Island of Hawai`i 

showing the location of the three National 

Parks along the Kona coast. Volcano names 

are shown in white.
 Pu`ukohol–

a Heiau National Historic Site, Hawai`i—Benthic Habitat Mapping

20°2' N 

20°1' 

155°50' W

Kilometers

0 1

Pu`ukohola– Heiau

National Historic Site

Kawaihae

Harbor

Kawaihae

Bay

Pelekane Bay

Samuel M. Spencer

Beach Park

Waikoloa/Waiulaula

Watershed

Kawaihae

Watershed

Makahuna

Gulch

Makeahua Gulch

Pohaukole Gulch

Kukui Gulch

Waiulaula Gulch

Park boundary

Study area

Watersheds

USCG reservation

Mauna Kea golf course

 Intermittent

 Perennial

Rivers/streams

Figure 2. Aerial photomosaic showing PUHE park boundary, study area, watersheds, streams, and place names 

discussed in text.
Data and Methods 

stream with a year-round water flow. Only during periods 

of extreme rainfall will water flow in the Makeähua and 

Pohaukole gulches, merge together in the park, and empty 

directly into Pelekane Bay.

In the late 1950s the reef off of PUHE was dredged to 

construct Kawaihae Harbor. Coral rubble was used in the construction of causeways and a revetment wall surrounding the 

commercial harbor. In the late 1960s the reef near Pelekane 

was blasted to create a small-boat harbor adjacent to the larger 

commercial harbor. Damage from these activities, in addition 

to a change in circulation patterns, has led to problems of high 

turbidity in Pelekane Bay (Tissot, 1998). 

Data and Methods

A standard for characterization of coral-reef environments was first implemented by the National Oceanic and 

Atmospheric Administration (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 m 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 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 

3 illustrates the complete methodology. 

Background Data

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 

using ESRI’s ‘GRID’ function. The bathymetric data have an 

average horizontal point spacing of 4 m ± ~3 m and a vertical 

resolution of ± 0.15 m, with a maximum water penetration of 

about 42 m (138 ft) in the study area. However, there are data 

gaps in the harbor and nearshore in Pelekane Bay, probably 

from lack of signal penetration due to poor water clarity (fig. 

4). Contour lines, hillshades, and slope maps were derived 

from this dataset using standard ArcMap functions. For further details regarding SHOALS data, see http://shoals.sam.

usace.army.mil.

Aerial Photography

True-color aerial photographs for Kawaihae Bay were 

collected in June 2000 by NOAA. For further details on 

NOAA aerial photography for Hawai`i see http://ccma.nos.

noaa.gov/products/biogeography/hawaii_cd/htm/flightln.

htm. These images were post-processed and mosaicked by 

the USGS, resulting in a digital mosaic with a resolution of 

1 meter per pixel (fig. 5). A two-step process was used to 

georectify, or geometrically correct, the aerial mosaic to realworld coordinates, using previously georegistered black and 

white USGS digital orthophoto quads (DOQs) of the area as 

an intermediate reference between the SHOALS data and the 

unregistered aerial photography. In the first step, a shadedrelief image generated using the SHOALS lidar bathymetry 

data was digitally merged with the DOQs. In the second step, 

Underwater photos

Video tows

SHOALS bathymetry

Base layers

and

in situ observations

Aerial Photography

NOAA random points

Field check

 observations

USGS random points

Interpretation

using 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

Figure 3. Flowchart illustrating methodology used to create 

Acquired Data habitat map. See text for complete description.
 Pu`ukohol–

a Heiau National Historic Site, Hawai`i—Benthic Habitat Mapping

Figure 4. Aerial photomosaic of Kawaihae Bay overlaid with SHOALS bathymetry coverage.

20°2' N 

20°1' 

20° 

19°59' 

19°58' 

155°51' W 155°50' 155°49' 

Kilometers

Contour interval 5 meters

0 1

Kawaihae

Harbor

Kawaihae

Bay

0

SHOALS bathymetry,

in meters

42

Park boundary

Mauna Kea

Golf Course

Pu`ukohola– Heiau

National Historic Site
Data and Methods 

Figure 5. Aerial photomosaic of Kawaihae Bay area showing PUHE park boundary and study area.

20°2' N 

20°1' 

20° 

19°59' 

19°58' 

155°51' W 155°50' 155°49' 

Mauna Kea

Golf Course

Kawaihae

Harbor

Kawaihae

Bay

Park boundary

Study area

Kilometers

0 1

Pu`ukohola– Heiau

National Historic Site
 Pu`ukohol–

a Heiau National Historic Site, Hawai`i—Benthic Habitat Mapping

20°2' N 

20°1' 

20° 

19°59' 

19°58' 

155°51' W 155°50' 155°49' 

Mauna Kea

Golf Course

Kawaihae

Harbor

Kawaihae

Bay

Park boundary

Study area

Kilometers

0 1

Pu`ukohola– Heiau

National Historic Site

Figure 6. Aerial photomosaic of Kawaihae Bay merged with shaded relief from SHOALS 

bathymetry. The combination of color and shaded relief assists with interpretation of benthic 

habitats.
Data and Methods 

Figure 7. Aerial photomosaic of northern Kawaihae Bay showing shaded relief, overlaid with locations of video 

transects and still photos.

20°2' N

20°1' 

155°50' W

Kilometers

0 1

Kawaihae

Bay

Park boundary

Photo locations

Video transects

Kawaihae

Harbor

Pu`ukohola– Heiau

National Historic Site
 Pu`ukohol–

a Heiau National Historic Site, Hawai`i—Benthic Habitat Mapping

the digital SHOALS/DOQ merge became the “geometric master” to which the aerial photography mosaic was matched.

A merge of the aerial photography and SHOALS bathymetry data shows shaded relief as well as color differences and was 

used for the interpretation of PUHE benthic habitats (fig. 6).

Acquired Data

Underwater Video and Still Photography

Nearly 17 trackline kilometers of underwater video footage (24 lines) and more than 150 still images were collected 

during two field surveys between April 2004 and August 

2004 to assist in interpretation of the aerial photography and 

lidar bathymetry (fig. 7). Navigation and other information 

regarding these surveys are available online at http://walrus.

wr.usgs.gov/infobank/a/a204hw/html/a-2-04-hw.meta.html, 

and http://walrus.wr.usgs.gov/infobank/a/a604hw/html/a6-04-hw.meta.html. Several types of camera systems were 

used, depending on water depth and collection methods. 

During diving and snorkeling, still images were collected 

using a hand-held digital camera (Sony DCS-P5 or Canon 

Elph S-400). 

Video imagery was obtained by towing a camera off 

the Alyce C, a 32-ft vessel operated by Capt. Joe Reich of 

Moloka`i (fig. 8), and a 13-ft motorboat owned by the NPS. 

The camera system used was a watertight video camera illuminated with a light-emitting diode (LED) ring designed by 

SeaViewer Underwater Video Systems (http://www.seaviewer.

com). The camera was mounted in a small aluminum handheld frame with a rear-mounted plastic fin (fig. 9). Live video 

was viewed in a shipboard laboratory on a standard CRT 

monitor and recorded directly to miniDV tape. Time, date, 

location, and ship speed were overlaid on the video using the 

Sea-Trak global positioning system (GPS) method, 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 (fig. 

10). Location data were recorded using a hand-held, WAASenabled, Garmin (http://www.garmin.com) GPS76 receiver. 

The stated horizontal accuracy of the Garmin GPS76 is better 

than 3 m when receiving WAAS corrections. 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) 

Figure 8. Photograph of the Alyce C of Moloka`i heading out of 

M–a`alaea Harbor, Maui.

Figure 9. Photograph of SEAVIEWER camera system rigged to 

collect towed video.

Figure 10. Photograph of shipboard system for navigation, 

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

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

Table 2. Major biologic 

cover classes. 

[Numbers represent 

UNIQUEID identifier.]

Table 3. Percent 

cover classes.

[Numbers represent 

UNIQUEID identifier.]

Major Biological Cover Percent Cover

0 Unknown 0 Unknown

1 Uncolonized 2 10–<50%

2 Macroalgae 3 50 –<90%

3 Seagrass 4 90 –100%

4 Coralline Algae

5 Coral

6 Turf

7 Emergent Vegetation

8 Mangrove

9 Octocoral

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. 11). 

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). 

software packages. Video could be interactively queried and 

geographically referenced feature annotations added to the 

database.

Benthic Habitat Mapping using GIS

Digital benthic habitat maps were created using ESRI’s 

ArcViewGIS v.3.2 software with a habitat digitizing extension 

created by NOAA (to download the extension see http://ccma.

nos.noaa.gov/products/biogeography/hawaii_cd/htm/digitize.

htm). 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 more than 300 polygons, covering more than 4 km2

, by interpreting features seen in both 

the aerial photographs and SHOALS bathymetry layers, with 

additional input from other data. 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). 

Classification Scheme

The classification scheme is based on a scheme established 

by NOAA’s biogeography benthic habitat mapping 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. As stated above, we are using NOAA’s 

definition of benthic habitats and their classification scheme as 

a starting point to provide continuity to the coral reef scientific 

community. However, we have made additional modifications 

to the classification scheme to better reflect the benthic habitats 

and geologic substrates found along the Kona coast.

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. 

Four major structure 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 
10 Pu`ukohol–

a Heiau National Historic Site, Hawai`i—Benthic Habitat Mapping

Detailed descriptions of habitats and zones, including example 

photographs, may be found in the appendix.

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

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).

This mapping project was performed concurrently with 

similar projects at two other National Parks along the Kona 

coast, Kaloko-Honoköhau National Historical Park (KAHO) 

Figure 11. Schematic diagram showing the generalized crossshelf 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.

and Pu`uhonua O Hönaunau National Historical Park (PUHO). 

A combination of field check data from all three parks was 

used to measure the accuracy of the PUHE benthic habitat 

map. Nearly 190 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. In addition, more than 50 sampling points 

from the NOAA database (http://ccma.nos.noaa.gov/products/

biogeography/hawaii_cd/htm/aap.htm) were used in the accuracy assessment.

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 (see http://walrus.wr.usgs.

gov/infobank/a/a204hw/html/a-2-04-hw.meta.html and http://

walrus.wr.usgs.gov/infobank/a/a604hw/html/a-6-04-hw.meta.

html to view list of analog holdings), and the other will be presented to the National Park Service to accompany this report. 

This report and project shapefiles are also available online 

(http://pubs.usgs.gov/sir/2006/5254).

Results

Kawaihae Bay

The reef system off PUHE in Kawaihae Bay is much 

different from those of the other two National Parks on the 

Kona Coast. As at KAHO and PUHO, the PUHE reef lacks the 

back reef, lagoon, and reef crest zones, and instead the shelf 

platform begins at the shoreline and slopes away to the deeper 

ocean. However, unlike the other two parks, PUHE also has a 

complex fore reef structure vertically accreting on top of the 

shelf, beginning approximately 0.25 km from shore (fig. 12). 

The coral reef systems offshore from KAHO and PUHO have 

very little, if any, vertical accretion.

The PUHE fore reef consists of a nearshore coralline 

algae-covered reef platform, transitioning into a distinct 

series of shore-normal spur and grooves, which then merge 

near the seaward edge and form an extensive aggregate reef. 

In between the shoreline and the fore reef, the shelf slope is 

covered with individual and aggregated patch reefs, the northernmost of which were dredged in the creation of Kawaihae 

Harbor (fig. 13). The roughly 4.15 km2

 study area is bisected 

by a broad expanse of sand-covered bottom with a gentle ~3° 

slope seaward, possibly formed by an old offshore stream 

extension during a sea-level lowstand (fig. 14). 

More than 2 km2

 (51 percent) of the study area consists of 

live accreting coral structures, including aggregate reef (1.41 

km2

) and spur and groove formations (0.64 km2) (fig. 15). The 

Mean high tide line

Spring low tide line

Shoreline/

Intertidal

Reef flat Reef

crest Fore reef

Shelf

Shelf

escarpment
Results 11

spur and groove structures dominate between –5 and –15 m 

(–15 and –50 ft). Below –15 m the aggregate reef dominates 

the fore reef (fig. 16), which then drops off sharply (~30–40°) 

into a sand-covered sea floor around –40 m (–130 ft). Nearly 

2 km2

 (46 percent) of the study area has at least 10 percent 

live coral cover (fig. 17). The highest densities of live coral 

are found on the buttresses (spurs) and on the aggregate reef at 

the seaward edge of the fore reef. In these places the live coral 

ranges from 50 to 100 percent cover and is predominantly 

Porites compressa. Along the shoreward edge of the fore reef, 

backed up along the main harbor breakwater and in the transition zone to patch reefs, the aggregate reef platform is covered 

with mostly coralline algae. The live coral growth found here 

is restricted to small juvenile colonies, predominantly Porites 

lobata, which is able to withstand high wave environments. A 

highly diverse live coral environment is found directly behind 

the main harbor breakwater, where it is sheltered from extreme 

wave conditions. 

Pelekane Bay

County-owned Samuel M. Spencer Beach Park borders 

the PUHE shoreline to the south, and the Kawaihae Harbor 

fill revetment abuts the north boundary. The waters just offshore from the Pu`ukohola and Mailekini Heiaus are known 

as Pelekane Bay. In 1998 the State of Hawai`i designated 

Pelekane Bay as a Category 1 impaired water resource, not 

meeting, or in imminent danger of not meeting, clean water 

guidelines (State of Hawai`i, 1998). Although not officially 

part of PUHE, the 6 acres (0.024 km2

) of Pelekane Bay are 

managed by the Park through an understanding with the State. 

After heavy rainfall, Makeähua and Pohaukole streams merge 

and breach a coastal sand berm, draining into Pelekane Bay 

near the edge of Kawaihae Harbor’s revetment wall and carrying silt and mud from upland erosion of the Kawaihae watershed. Kawaihae Harbor limits the natural flushing in this small 

bay, thus exacerbating siltation problems (Tissot, 1998). In 

this shallow murky water lies Hale o Kapuni Heiau, dedicated 

to the Hawaiian shark gods. Hale o Kapuni is now completely 

submerged, and the remains have been covered over with silt 

and dredge spoils. 

A belt of broken coral and rocks from dredge spoils 

scattered on volcanic pavement is found running along the 

Kawaihae Harbor revetment wall to approximately 40 m into 

Pelekane Bay (fig. 18). Classified as uncolonized, this is an 

area of high siltation and limited turf algal growth. The lack of 

algae in this area may be due to light limitations from turbidity (Ball, 1977). A thin ribbon (~3 to 5 m) of aggregated patch 

reefs covered with turf algae and sediment lies between this 

belt and the sand channel in the middle of the bay. The ancient 

Hawaiian royal courtyard at Pelekane Beach is found on the 

southwest-facing shore of Pelekane Bay. On the PUHE side 

of the small bay, uncolonized volcanic rocks and boulders line 

the shore’s edge.

Aggregated patch reefs are found from the southern point 

of the harbor revetment wall, stretching across the mouth 

of Pelekane Bay and south along the coast from Samuel M. 

Spencer Beach Park to the mouth of Kukui Gulch, only broken 

by the broad sand plain offshore from the beach park. The live 

coral found on the patch reefs is limited and consists mostly of 

small colonies of Pocillopora damicornis and Porites lobata. 

The patch reefs nearest to shore are being overtaken by turf 

Figure 12. Three-dimensional perspective view of area of study in Kawaihae Bay, 

showing geographic reef zonation overlaid on aerial photomosaic. The area has a 

complex fore-reef structure on top of the underlying shelf. View is to the northeast. 

Approximate distance along the bottom of the figure is 2.5 km.

vertical exaggeration = 2

Kawaihae Harbor

K a w a i h a e

B a y

Park boundary

Dredged

Fore reef

Land

Shelf

Shoreline/intertidal

Pu`ukohola– Heiau

National Historic Site
12  Pu`ukohol–

a Heiau National Historic Site, Hawai`i—Benthic Habitat Mapping

Figure 13. Aerial photomosaic of Pu`ukohol–a Heiau National Historic Site, overlaid with 

benthic habitat map.

Kilometers

0 1

Mud, uncolonized

Sand, uncolonized

Aggregate reef, uncolonized

Aggregate reef, 10–<50% coralline algae

Aggregate reef, 50–<90% coralline algae

Aggregate reef, 10–<50% coral

Aggregate reef, 50–<90% coral

Aggregate reef, 90–100% coral

Spur-and-grove, 50–<90% coral

Individual patch reef, 10–<50% coral

Individual patch reef, 50–<90% coral

Aggregated patch reef, uncolonized

Aggregated patch reef, 10–<50% coral 

Aggregated patch reef, 50–<90% coral

Aggregated patch reef, 10–<50% turf

Aggregated patch reef, 50–<90% turf

Volcanic pavement, 10–50% rocks

 and boulders, uncolonized

Volcanic pavement, uncolonized

Volcanic pavement, 10–<50% coral

Volcanic pavement, 50–<90% turf

Volcanic pavement, >50% rocks 

 and boulders, uncolonized

Volcanic pavement, >50% rocks 

 and boulders, 10–50% coral

Volcanic pavement , >50% rocks 

 and boulders, 10–50% turf

Reef rubble, uncolonized

Reef rubble, 10–<50% coralline algae

Reef rubble, 10–<50% coral

Reef rubble, 10–<50% turf

Other, land

Other, artificial

Benthic habitats

20°2' 

20°1' 

155°50'

Park boundary

Pu`ukohola– Heiau

National Historic Site
Results 13

Figure 14. Aerial image of northern Kawaihae Bay showing 

shaded relief and cross-section profiles of the reef. Profile A-A’

illustrates a reef cross-section with a typical 30° to 40° slope 

break. Profile B-B’ is taken down the middle of the large sand 

area bisecting the study area. Profile C-C’ shows the along-reef 

topography of the spur-and-groove system.

Figure 15. Pie chart showing the 

breakdown of dominant reef structures 

of the PUHE study area. Aggregate reef 

makes up more than 1.4 km2

; spur and 

groove encompasses nearly 0.65 km2

.

20°2' 

20°1' 

155°50'

Kilometers

0 1

Kawaihae

Harbor

A

A‘

B

B‘

C‘

C

Kawaihae

Bay

0

0

20

40

200 400

0

0

20

400

Distance, in meters

Depth, in meters

800

0

A A’

C C’

B B’

0

20

40

400 800

Slope = 34.398°

Slope = 3.195°

Spur and groove structures

Pu`ukohol−a Heiau

National Historic Site

Pu`ukohol−a Heiau

National Historic Site

Aggregate reef

1,407,830 m2

35%

Sand

1,350,900 m2

33%

Mud

374,902 m2

9%

Reef rubble

18,533 m2

<1%

Land

13,188 m2

<1%

Spur and groove

642,749 m2

16%

Volcanic pavement

>50% rocks/boulders

58,125 m2

1%

Volcanic pavement

10–50% rocks/boulders

10,756 m2

< 1%

Volcanic Pavement

59,324 m2

1%

Aggregated

patch reef

171,289 m2

4%

Artificial

32,563 m2

1%

Individual patch reef

4,467 m2

<1%
14  Pu`ukohol–

a Heiau National Historic Site, Hawai`i—Benthic Habitat Mapping

Figure 17. Pie chart showing the breakdown of major biologic 

coverage in the PUHE study area. Nearly 2 km (46 percent) of the 

study area is covered with a minimum of 10 percent coral. Coralline 

algae cover 7 percent of the reef, mostly on the fore reef just 

offshore of the harbor breakwater and on the nearshore patch reefs.

Figure 16. Graph showing proportions of dominant structures 

with depth at PUHE. Spur and groove structures dominate at 

depths between 5 and 15 m. Below 15-m depth, the study area is 

dominated by aggregate reef.

algae and sediment, whereas coralline algae dominate the reef 

approximately 200 m offshore. 

Accuracy of Maps

An accuracy assessment was performed for the major 

biological covers (table 5). A total of 241 randomly selected 

points for all three National Parks (PUHO, KAHO, and 

PUHE) were checked in the field. The overall accuracy of 

91.29 percent (with a 95-percent confidence interval of ± 1.1) 

indicates which points on the map were classified correctly 

according to the field check. Producer’s accuracy is an indication of how well we correctly identified pixels for each different class (for example, coral = 96.39 percent, uncolonized 

= 75.00 percent). User’s accuracy is the probability that, for a 

classified pixel on the map, the map user will actually find that 

class in the field (for example, coral = 94.67 percent, octocoral 

= 60.00 percent). A tau coefficient of 0.9005 was calculated 

as described by Ma and Redmond (1995), and indicates that 

90.05 percent more points were classified correctly than would 

be expected by chance alone. 

After accuracy assessment calculations were performed, 

any misinterpreted polygons identified on the Kona coast reef 

maps were corrected using the field check data, thus increasing the overall accuracy of the final maps to greater than 91.29 

percent.

Resource Concerns

An important concern within the study area is water 

turbidity and siltation in Pelekane Bay. Sediment-laden runoff 

from the Makeähua/Pohaukole Gulch during periods of high 

rains is trapped in the embayment because of the alteration of 

the coastline at Kawaihae Harbor. With the natural flushing 

reduced, sedimentation from high turbidity levels has resulted 

not only in the degradation of the nearshore ecosystem, but has 

also contributed to the burial of Hale o Kapuni Heiau. Remediation efforts, such as the installation of sediment traps upstream, 

can help stop the influx of mud and pollutants to the nearshore 

environment. Dredging can remove the current build-up of sediment, but care needs to be taken so that the submerged heiau 

is not damaged any further. Increasing the circulation in the 

embayment will help restore it to natural flushing conditions. 

Acknowledgements

This project was funded by the USGS Coastal and Marine 

Program’s Coral Reef Project, and by the U.S. National Park 

Service. The authors thank Pat Chavez and his group from 

the USGS in Flagstaff for coordinating our acquisition of 

the SHOALS bathymetric data and their work on processing 

the aerial photomosaics. Will Smith and colleagues from the 

University of Hawai`i Coral Reef Assessment and Monitoring 

Program (CRAMP) team performed the third-party field-check 

43% Coral 46%

1,904,500 m2

46%

Coralline

algae

303,801 m2

7% Unclassified

45,751 m2

1% Turf algae

104,851 m2

3%

Uncolonized

1,785,730 m2

43%

0 20 40 60 80 100

Areal percent

0

5

10

15

20

25

30

35

40

Depth,

in meters

Dominant structures

Aggregate reef

Aggregated patch reef

Artificial

Individual patch reef

Land

Mud

Reef rubble

Sand

Spur and groove

Volcanic pavement, >50% rocks 

 and boulders

Volcanic pavement, 10–50% rocks 

 and boulders

Volcanic pavement 
Results 15

Table 5. Matrix showing accuracy assessment for the major biological cover classes.

Found to be in field

Total User’s

Coral Accuracy Coralline 

Algae

MacroalgaeTurf 

Algae Octocoral Emergent Vegetation Uncolonized

As

mapped

Coral 160 169 94.67%

Coralline Algae 0 15 0 0 0 0 1 16 93.75%

Macroalgae 0 0 0 0 0 0 3 3 0.00%

Turf Algae 0 0 0 0 0 0 0 0

Octocoral 0 0 1 0 3 0 1 5 60.00%

Emergent Vegetation 0 0 0 0 0 0 0 0

Uncolonized 6 0 0 0 0 0 42 48 87.50%

Total 166 16 1 0 4 0 54

Producer’s Accuracy 96.39% 93.75% 0.00% 75.00% 77.78% 241

Diagonal Sum = 220

Overall Accuracy = 91.29%

Figure 18. Enlarged portion of the benthic habitat map showing Pelekane Bay and PUHE shoreline. 

Sand, uncolonized

Aggregate Reef, uncolonized

Aggregate Reef, 10–<50% coralline algae

Aggregate reef, 50–<90% coralline algae

Aggregate reef, 10–<50% coral

Individual patch reef, 50–<90% coral

Aggregated patch reef, uncolonized

Aggregated patch reef, 10–<50% coral 

Aggregated patch reef, 10–<50% turf

Aggregated patch reef, 50–<90% turf

Volcanic pavement, 10–5<0% rocks and 

 boulders, uncolonized

Volcanic pavement, >50% rocks and 

 boulders, uncolonized

Volcanic pavement, >50% rocks and 

 boulders, 10–<50% turf

Other, land

Benthic habitats

155°49’30”

20°1’30”

20°1’40”

Meters

0 100

Park boundary

Pu`ukohola– Heiau

National Historic Site
16  Pu`ukohol–

a Heiau National Historic Site, Hawai`i—Benthic Habitat Mapping

observations and provided the accuracy assessment calculations. Sallie Beavers from Kaloko-Honoköhau NHP supplied 

us with the smaller boats (motorboats and kayaks) and assisted 

with logistics while we were on island. This manuscript 

benefited from reviews by Brian Edwards and Mike Field. 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.

References

Ball, F.W., 1977, Benthic marine algae of the coastal waters 

of Pu`ukoholä Heiau National Historic Site: University of 

Hawai`i, Department of Botany, Cooperative National Park 

Resources Studies Unit, Technical Report #16, Contribution 

Number CPSU UH 001/7, 12 p.

Coyne, M.S., Battista, T.A., Anderson, M., Waddell, J., Smith, 

W., Jokiel, P., Kendall, M.S., and Monaco, M.E., 2003, Benthic habitats of the main Hawaiian Islands: NOAA Technical Memorandum NOS NCCOS CCMA 152 [http://ccma.

nos.noaa.gov/products/biogeography/hawaii_cd/index.htm]. 

Kendall, M.S., Monaco, M.E., Buja, K.R., Christensen, J.D. 

Kruer, C.R., Finkbeiner, M., and Warner, R.A., 2001, Methods used to map the benthic habitats of Puerto Rico and 

the U.S. Virgin Islands: U.S. National Oceanic and Atmospheric Administration [http://ccma.nos.noaa.gov/products/

biogeography/benthic/index.htm].

Kendall, M.S., Buja, D.R., Christensen, J.D., Kruer, C.R., 

and Monaco, M.E., 2004, The seascape approach to coral 

ecosystem mapping; an integral component of understanding the habitat utilization patterns of reef fish: Bulletin of 

Marine Science, v. 75, no. 2, p. 225 –237.

Lillesand, T.M., and Keifer, R.W., 1994, Remote sensing and 

image interpretation (3rd ed.): New York, John Wiley and 

Sons, 750 p.

Ma, Z., and Redmond, R.L., 1995, Tau coefficients for accuracy assessment of classification of remote sensing data: 

Photogrammetric Engineering and Remote Sensing, v. 61, 

p. 435 –439.

National Oceanic and Atmospheric Administration National 

Centers for Coastal Ocean Science, 2005, Shallow-water 

benthic habitats of American Samoa, Guam, and the Commonwealth of the Northern Mariana Islands: NOAA Technical Memorandum NOS NCCOS 8 [http://ccma.nos.noaa.

gov/products/biogeography/us_pac_terr/index.htm].

Richmond, B.M., Cochran, S.A., and Gibbs, A.E., 2008, 

Geologic resource evaluation of Pu`ukoholä Heiau National 

Historic Site, Hawai`i; Part I, Geology and coastal landforms: U.S. Geological Survey Open-File Report 2008-1190, 

23 p. [http://pubs.usgs.gov/of/2008/1190/].

Rohman, S.O., and Monaco, M.E., 2005, Mapping southern 

Florida’s shallow-water coral ecosystems; an implementation plan: National Oceanic and Atmospheric Administration Technical Memorandum NOS NCCOS 19, 

39 p. [http://ccma.nos.noaa.gov/publications/biogeography/

FloridaTm19.pdf].

State of Hawaii, 1998, The Hawaii Unified Watershed 

Assessment: Department of Health, Clean Water Branch, 

Polluted Runoff Control Program [http://www.state.hi.us/

dbedt/czm_initiatives/6217_pdf/UWA.pdf].

Tissot, B.N., 1998, Changes in the marine habitat and biota 

of Pelekane Bay, Hawai`i over a 20-year period: University 

of Hawai`i at Hilo, Marine Science Department, report 

prepared for U.S. Fish and Wildlife Service, Honolulu, 

Hawai`i, 34 p.
Appendix 17

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 meters 

Example of muddy shallow area exposed at low tide. of sand or bare pavement (grooves).

(Kawela, Moloka`i) 

Example of uncolonized sand. (Kaloko-Hon–okohau, Hawai`i)

Example of aggregate reef with 90–100 percent coral. 

(Kawaihae Bay, Hawai`i)

Example of spur-and-groove reef system with 90–100 percent 

coral cover on the spurs. (Kawaihae Bay, Hawai`i)
18  Pu'ukohol–

a Heiau National Historic Site, Hawai`i—Benthic Habitat Mapping

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)

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 19

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 highenergy 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)
20 Pu'ukohol–

a Heiau National Historic Site, Hawai`i—Benthic Habitat Mapping

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 

spur-and-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.