monitoring of the hnmzs canterbury artificial reef

Clockwise from top right

http://www.divenz.com/images/canterbury_dive.JPG

http://staples-moon.net/bruce/pics/rakiura/140024.jpg

http://www.militaryimages.net/photopost/data/592/New_Zealand_Navy

_-_frigate_HMNZS_Canterbury_-_3.jpg

http://www.tapeka.com/HMNZS%20Waikato%20Sunk2.jpg

Monitoring of the HMNZS Canterbury artificial reef, July 2008

Investigation of colonisation, succession and

community enhancement.

Michael J. Fairweather and Joseph W. McKenzie Diploma in Marine Studies Bay of Plenty Polytechnic

[email protected] [email protected]

Monitoring of the HMNZS Canterbury artificial Reef, July 2008 Diploma in Marine Studies

McKenzie, J. W. & Fairweather, M. J. Bay of Plenty Polytechnic of 26

Monitoring of the HMNZS Canterbury artificial reef, July 2008

Investigation of colonisation, succession and community enhancement.

This report was compiled and produced by:

Michael J. Fairweather

&

Joseph W. McKenzie

Project Co-ordinator:

Caroline Schweder-Goad

Diploma in Marine Studies

Bay of Plenty Polytechnic

Tauranga

[email protected]

[email protected]

Front cover images by: Military Images, 2006; Tapeka, 2008; Dive HQ Bay of Islands, 2008; BBS Divers, 2008; Stewart

Island, 2004



Abstract

The HMNZS Canterbury is a decommissioned Navy Vessel that was scuttled in November 2007 in

Deep Water Cove, Northland, New Zealand.

A monitoring plan was designed to investigate colonisation, marine community enhancement,

succession and to monitor any negative impacts of the ship wreck on its surrounding environment. This

is report details the first surveys carried out on the vessel in July 2008.

Various data was collected with various methods from different zones of the vessel. This data provides

information on colonisation of the wreck, species diversity and species size at different areas of the

vessel.

It was found that different zones of the vessel hosted different levels of colonisation and species

diversity. Considerable colonisation has occurred on the wreck since the scuttling with some surfaces of

the wreck being completely colonised by encrusting invertebrates.

Generally resident fish to the wreck are small in size which suggests they are locals to the wreck and not

migrating populations from surrounding areas.

The next surveys of the monitoring plan are scheduled for November 2008.



Acknowledgments

Thank you to

Shane Housham and Julia Riddle

Northland Dive

Far North District Council

The Canterbury Charitable Trust

Darryl Harrison

Bay of Plenty Polytechnic

Monique Retter

Daniel Sharp

O2 Dive NZ

And a very special thank you to Caroline Schweder-Goad for your guidance and knowledge



Table of Contents

1.0 Introduction ................................................................................................... 6

1.1 HMNZS Canterbury F421 ................................................................................................................ 6

1.2 Stakeholders ...................................................................................................................................... 6

1.3 Monitoring Plan ................................................................................................................................ 7

1.4 Past Studies ....................................................................................................................................... 7

1.5 Economic Benefits of Shipwrecks .................................................................................................... 8

1.6 HMNZS Canterbury Survey July 2008............................................................................................. 8

2.0 Methods ........................................................................................................ 9

2.1 HMNZS Canterbury Survey July 2008............................................................................................. 9

2.2 Data Collection ............................................................................................................................... 11

2.2 Data Collection ............................................................................................................................... 12

2.3 Data analysis ................................................................................................................................... 13

3.0 Results ......................................................................................................... 14

3.1 Average Colonisation of Different Areas ....................................................................................... 14

3.2 Species Richness ............................................................................................................................. 15

3.3 Macro Mobile Species, Presence and Average Size ....................................................................... 16


3.4 Species Diversity ............................................................................................................................ 17

4.0 Disscussion ................................................................................................. 19

4.1 Average Colonisation of Different Areas ....................................................................................... 19

4.2 Species Richness ............................................................................................................................. 19


4.4 Species Diversity ............................................................................................................................ 20

4.5 Conclusion ...................................................................................................................................... 20

4.6 Future Monitoring ........................................................................................................................... 21

5.0 References ................................................................................................... 22

6.0 Appendix ..................................................................................................... 24



1.0 Introduction

1.1 HMNZS Canterbury F421

The HMNZS Canterbury was built for the Royal New Zealand Navy in Scotland and was commissioned

in October 1971 as F421 (Middleton, 2005).

The Canterbury is a 113.4 metre long vessel and was decommissioned in 2005 (Canterbury Charitable

Trust, 2008).

The Canterbury Wreck was purchased by the Bay of Island Charitable Trust and successfully scuttled in

November 2007 in Deep Water Cove, Bay of Islands, New Zealand (figure 1) (Canterbury Charitable

Trust, 2008).

The HMNZS Canterbury rests in Deep water cove and occupies a depth ranging from 12 to 37 metres in

the water column (figure 2).

1.2 Stakeholders

The Canterbury Charitable trust is a 50:50 partnership between marine recreational interests and the

Rawhiti Iwi (Canterbury Charitable Trust, 2008). The objectives for the wreck held by the Charitable

trust include enhancement of social and economic development in the Bay of Islands, employment of

local people, fisheries enhancement and conservation of Deep Water Cove’s marine community

(Canterbury Charitable Trust, 2008).

The Far North District Council value the wreck as an attraction to the region therefore benefiting

tourism and the local economy (Far North District Council, 2008).

Deep Water Cove

Figure 1. Location of Deep Water Cove, Cape Brett, Northland, New Zealand. (Pikasa Web, 2008;

Northland fishing 2008)



1.3 Monitoring Plan

A future monitoring plan has been requested by the Canterbury Charitable Trust and the Far North

District council to observe the colonisation and succession of the wreck and also to survey positive and

negative impacts of the wreck to the surrounding environment of Deep Water Cove. The monitoring

plan was designed to illustrate if the objectives of the wreck, held by the different stakeholders, are

feasible given the success of the wreck as an artificial reef.

Prior to the scuttling of the HMNZS Canterbury in November 2007, the area of Deep Water Cove was

surveyed. This baseline survey was completed by Retter and Newcombe in October 2007 to determine

the cove’s biotic state before the scuttling of the HMNZS Canterbury. This is to be used as a benchmark

for future monitoring of Deep Water Cove (Retter & Newcombe, 2008).

The monitoring plan of the HMNZS Canterbury consists of a survey of the wrecks colonisation in July

and November of 2008. An additional survey of the surrounding areas of Deep Water Cove is to be

carried out in November 2008. Surveying the surrounding areas of Deep Water Cove is to be a repetition

of Retter and Newcombe’s survey of October 2007. This is to identify any community enhancement of

Deep Water Cove over time. Annual November surveys of the wreck and surrounding areas of Deep

Water Cove will be carried out there after. This will allow for an analysis of succession of the wreck

over time.

If the Canterbury is successful as an artificial reef this should have flow on effects to the surrounding

environment by enhancing the marine community. The scientific purpose of the monitoring plan is to

document and analyse the colonisation, succession and community enhancement of the HMNZS

Canterbury, and the surrounding areas of Deep Water Cove (Retter and Newcombe, 2007)

1.4 Past Studies

Similar studies of shipwrecks in northern New Zealand waters have been documented. These include the

Rainbow Warrior wreck at the Cavalli Islands (Ross-Watt & Clarke, 1997), the Canterbury’s sister ship

the HMNZS Waikato wreck off the coast of Tutukaka (Retter & Newcombe, 2007) and the Taioma off

the south-eastern side of Motiti Island in the Bay of Plenty. (Guinness, Betty & Kennedy, 2005).

Figure 2. Diagram of the HMNZS Canterbury in its final location (Canterbury Charitable Trust, 2008)



The Rainbow Warrior rests in Matauri Bay, Cavalli Islands. This vessel is a prime example of a wreck

becoming an artificial reef and enhancing the surrounding marine community. Once the Rainbow

Warrior was rested in its final location, a succession of marine plants and animals began to occupy the

wreck and community composition visibly changed over time (Grace, 2005). The wreck is now covered

in invertebrate life, hosts schooling fish, and attracts divers from all around the world (Enderby, 2002).

Past studies of the Rainbow Warrior wreck have shown an increase in large predatory fish abundance

after one year and full colonisation of the wreck occurred after approximately three years (Muherami,

2004). In other cases like the HMNZS Waikato, full blankets of marine life, which help attract other reef

dwellers, had developed after three years (Muherami, 2004).

Studies carried out on ship wrecks in South East Florida USA have shown that significantly larger fish

diversity has been present on the artificial vessel reefs compared to natural reefs within the same area.

These studies concluded that artificial reefs like ship wrecks do not attract fish away from pre-existing

natural reefs more that they create their own diverse communities (Arena, Jordan & Spieler, 2007). This

view is commonly supported by many scientists who believe that shipwrecks and artificial reefs are

tools that can help boost failing fish stocks and repopulate local marine communities (Gravitz, 2000).

Some scientists, however, believe that various fish species, especially commercially viable stocks, do

not use reefs to reproduce but simply as a location that provides shelter and food (Gravitz, 2000). They

therefore believe that target fish stocks are migrating from natural to artificial reefs, as a result, stocks

are merely being redistributed as appose repopulated (Gravitz, 2000).

If the assumption of migrating fish stocks favouring artificial reefs is valid, this may result in increased

densities of fish populations congregating in one location; the artificial reef. This therefore leaves fish

populations more susceptible to over exploitation due to increased fishing pressure that may be exerted

on artificial reefs (Grossman, Jones & Seaman, 1997).

1.5 Economic Benefits of Shipwrecks

The HMNZA Tui and the HMNZS Waikato are located off the coast of Tutukaka in Northland New

Zealand. The wrecks were sunk in 1999 and 2000 respectively, since then both wrecks have become

blanketed in encrusting marine life and are home to thousands of fish. Along with the Poor Knights

Islands, located near by, the wrecks have been a major attraction for international visitors, as well as

locals. Tutukaka has seen an estimated 20,000 divers diving on the Waikato alone (Schaffler, 2007).

Ship wrecks have benefited the diving and tourism industries economically the world over. Possibly the

most famous shipwreck in the world, the SS President Coolidge, was sunk in 1942 after hitting a mine

off the coast of Vanuatu’s largest Island, Espiritu Santo. The accident has transformed Espiritu Santo

into a renowned, must see destination for divers worldwide, for the Coolidge is the largest, most in tack

and accessible wreck of World War Two (Vanuatu Tourism Office, 2007).

1.6 HMNZS Canterbury Survey July 2008

This report details the first survey carried out on the HMNZS Canterbury for the monitoring plan of the

vessel. This survey was carried out in July 2008.

The purpose of this study was to document the state of colonisation of the HMNZS Canterbury to date.

Surveys were carried out on different zones of the vessel. This data was used to compare the state of

colonisation and the biodiversity in different zones of the vessel. This data will also be used as a

reference in the monitoring of succession on the vessel over time.



The survey is designed to illustrate the success of the HMNZS Canterbury acting as an artificial reef and

these surveying methods will be repeated in future monitoring of the wreck. Repetition of the method

will allow clear documentation to be made of the different stages of the wrecks succession.

2.0 Methods Methods for surveying the HMNZS Canterbury wreck detailed in the monitoring plan are derived from

Ross-Watt and Clarke’s survey of the Rainbow Warrior in 1997 (Ross-Watt & Clarke, 1997).

Sub tidal surveys were completed at different pre-determined sites on the wreck. Survey techniques are

specific to each survey site and include visual surveys; quadrat readings at regular intervals along pre-

determined transect lines and haphazard quadrat sampling. Fish, macro invertebrates, algae and other

species present were recorded in these surveys.

The HMNZS Canterbury is located in Deep water cove at 35° 11’ 34.69” S, 174° 17’ 48.7” E.

2.1 HMNZS Canterbury Survey July 2008

Surveying of the HMNZS Canterbury took place from the 1st to the 9

th of July 2008 and followed the

standard methods of the monitoring plan illustrated below (table 1 & figure 3).

Table 1. Methodology of the HMNZS Canterbury Monitoring Plan

Method no.

Method description Zones Location Site details

1. Horizontal Transects

The transect line was positioned along a horizontal surface. The bottom left

hand corner of the 0.5 x 0.5m quadrat was placed in line with the 0m mark. All

macro-species present within the quadrat, their percentage cover and/or abundance, and an estimate the over-all colonisation cover of the quadrat

was recorded. This was repeated at 2m intervals along the transect line.

Zone A Aft Deck

The centre line of the deck was used as a guide for the transect line. The transect

line was run from the aft winch to the edge of the entrance to the aft storage room.

2. Vertical Transects

A weighted transect line was lowered from the top of the hull to the sea floor (unless otherwise stated in site details

section). The bottom left hand corner of the 0.5 x 0.5m quadrat was placed in line with the 0m mark located at the sea floor. All macro-species present within the quadrat, their percentage

cover and/or abundance, and an estimate the over-all colonisation cover of the quadrat was recorded. This was

repeated at 2m intervals along the transect line.

Zone B Stern Hull

Diver A was located at the top of the stern hull in line with the centre line of the

vessel whilst Diver B ran out the transect line along the centre line of the hull. The

0m mark was located at the deepest point of the vertical surface of the hull.

Zone C Port

Forward Hull

The transect line was lowered in line with the forward bollards at the top of the deck incline and ran down the hull to the sea

floor.

Zone D Port Mid-ship Hull

The transect line was lowered in line with the forward arm of the davit and ran down

the hull to the sea floor.



Zone E Port Aft Hull The transect line was lowered in line with the hanger entrance and ran down to the

sea floor.

Zone F Starboard Forward

Hull

The transect line was lowered in line with the forward bollards at the top of the deck

incline and ran down to the sea floor.

Zone G Starboard Mid-ship

Hull

The transect line was lowered in line with the forward arm of the davit and ran down

to the sea floor.

Zone H Starboard

Aft Hull

The transect line was lowered in line with the hanger entrance and ran down to the

sea floor.

Zone I

Centre Line Below Bridge

Windows

The transect line was lowered from the bottom of the centre window of the bridge

and ran down to the deck

3. Visual Surveys

A visual survey not lasting more than 10 minutes was carried out recording

all macro mobile species present. Abundance and sizes were estimated and recorded (<10cm, 11-20cm, 21-30cm, 31-40cm, 41-50cm, >50cm).

Zone J Hanger A visual survey was carried out in the

hanger, all depths were covered.

Zone K Middle Funnel

A visual survey was carried out in the middle funnel.

Zone L Gun Turret

Room A visual survey was completed in the gun

turret room.

Zone M Bridge

Wheelhouse A visual survey was completed in the bride

wheelhouse.

Zone N Rear

Bunkroom A visual survey was completed in the rear

bunkroom

4.Visual Hand Rail Surveys

A visual survey not lasting more than 10 minutes was carried out recording

all species present on the top handrail.

Zone O i

Port Forward Handrail

A visual survey was carried out starting in line with the bridge wheelhouse entrance

and finishing to the bow.



Zone O ii

Starboard Forward Handrail

A visual survey was carried out starting in line with the bridge wheelhouse entrance

and finishing to the bow.

Zone P i

Port Aft Handrail

A visual survey was carried out starting from stern and ran the entire length of the

rail.

Zone P ii

Starboard Aft Handrail

A visual survey was carried out starting from stern and ran the entire length of the

rail.

5. Haphazard Sampling

A 0.5 x 0.5m quadrat was haphazardly placed 5 times within the given area. All macro-species present within the

quadrat, their percentage cover and/or abundance, and an estimate the total percentage colonisation cover of the

quadrat was recorded.

Zone Q Hanger roof Survey was completed on the hanger roof.

6.Visual Fish

Surveys

The wreck was circumnavigated. Diver A led the dive, maintaining a constant depth whilst Diver B recorded all fish

species within 5 metre of them. Species present, estimates of their

abundance and size (<10cm, 11-20cm, 21-30cm, 31-40cm, 41-50cm, >50cm)

were recorded.

Zone R Sea floor Survey was completed 1.5m above the

sea floor

Zone S 24 metres

Depth Survey was completed at a depth of 24m

Zone T 15 metres

Depth Survey was completed at a depth of 15m

Figure 3. Location of survey zones of the HMNZS Canterbury.



2.2 Data Collection

For methods one, horizontal surveys; two vertical surveys; four visual hand rail surveys; and five

haphazard sampling, the following was recorded:

Date the survey was preformed

The time the survey was carried out

The zone being surveyed

The location on the vessel the survey was carried out

The method being used

The waters visibility

Recorder of the survey

Total transect length (only applicable with methods 1 and 2)

Distance along transect line that individual quadrats were recorded (only applicable to

methods 1 and 2)

The depth of each individual quadrat

Estimation of the total percentage cover within each quadrat (not applicable to method 4)

Each individual species present within the quadrat (not applicable to method 4)

The frequency and/or percentage coverage of each species present within each quadrat

(not applicable to method 4)

Any important observations or notes concerning the survey zone

This was filled out during the survey dive on a table (figure 4.)

Figure 4. Data collection table for methods 1, 2, 4 and 5

Location (Location on vessel) Method No. (1-6)

Date (dd/mm/yy) Visibiltiy (metres)

Transect Length (metres) Notes

Zone (A-T)

Recorder

Time (time of the day)

Distance along T-line Depth Total % Cover Species Abundance Frequency

(per

cent

age)

(num

ber o

f indi

vidual

s)

(met

res)

(met

res)

(per

cent

age)

(scie

ntific

nam

e)

(per

cent

age)

(num

ber o

f indi

vidual

s)

(met

res)

(met

res)

(per

cent

age)

(scie

ntific

nam

e)



For methods three, visual surveys; four, visual handrail surveys; and six visual fish surveys, the

following data was recorded:

Location on the vessel that the survey was carried out

Method being used for the survey

Survey zone being recorded

The waters visibility

The date the survey was preformed

The time the survey was preformed

The recorder of the survey

The depth that the survey was carried out at

Species present at/in the survey zone

Estimations of individual species size; the longest length of the animal (not applicable for

method 4)

Any important observations or notes concerning the survey zone

This was filled out during the survey dive on the table illustrated in figure 5.

2.3 Data analysis

Average Colonisation of Different Areas:

An average percentage cover of colonising organisms was calculated for different areas of the HMNZS

Canterbury. These percentages were derived from all quadrats recorded in given areas of the vessel.

These areas were as follows:

Vertical surfaces, Port-side Hull: Consisting of quadrats recorded from zones C, D and E

Vertical surfaces, Starboard-side Hull: Consisting of quadrats recorded from zones F, G and H

Vertical Surfaces, Stern Hull: Consisting of quadrats recorded in zone B

Location (Location on vessel) Method No. (1-6)

Zone (A-T) Visibiltiy (metres)

Date (dd/mm/yy) Notes

Time (time of the day)

Recorder

Depth (metres)

Species <10cm 10-19cm 20-29cm 30-39cm 40-49cm 50cm<

(scie

ntific

nam

e)

(num

ber o

f indi

vidual

s at

this

size

)

(scie

ntific

nam

e)

(num

ber o

f indi

vidual

s at

this

size

)

Figure 5 Data collection table for methods 3, 4 and 6



Vertical Surfaces, Bridge Exterior Wall: Consisting of quadrats recorded in zone I

Horizontal Surfaces: Consisting of quadrats recorded in zone A and Q

These averages are used to compare the degree of colonisation on different areas of the wreck.

Species Richness:

Using the same areas as above, an average species richness was calculated for each. This gives the

average species richness for a quadrat recording in each area. These averages are used to compare the

species richness in different areas of the wreck.

Total species richness of the forward and aft handrails was also compared. This data was obtained from

survey zone S, P and O.

Macro Mobile Species:

Data obtained from the visual room surveys, method three, survey zones J through to N was used to

compare species presence in each zone and also calculate the average size of each species present in

each room. This allows comparison of species richness and average species size between rooms.

Average sizes of fish species are calculated using the mid point of the size class e.g. a fish in the size

class 10-19cm would be recorded at 15cm.

Species diversity:

The Shannon Species Diversity Index was used to calculate the species diversity (H’) of the three zones

R, S and T from method six, visual fish surveys. This diversity index was also used to calculate species

richness (S), number of individuals (N) and species evenness (h/ln(S)) for each survey zone.

This was used to compare different aspects of the communities present at the different depths surveyed.

This included species diversity, species richness, species evenness and total number of individuals.

The Shannon Species Diversity Index was also used to calculate the species diversity (H’), species

richness (S), number of individuals and species evenness of zones J through to N, method three, visual

surveys.

This was used to compare the species diversity, species richness, species evenness and total number of

individuals present in each of the five different rooms.

3.0 Results

3.1 Average Colonisation of Different Areas

The average percentage coverage calculated from different zones on the HMNZS Canterbury showed

that the exterior forward wall of the Bridge Wheel House was the most densely colonised area surveyed

(figure 6).

Not only was the exterior forward wall of the Bridge Wheel House most densely populated, surveys also

showed it to have the least variation between quadrat readings with all quadrats samples taken

containing 100 percent coverage of colonising organisms. This results in the zone having a standard

deviation of zero (figure 6).

The Port-Side Hull on average is more densely populated than the Starboard-Side Hull. There is a large

variation between individual quadrat recordings of the starboard side and the difference between the two

zones is relatively small (figure 6).



The Stern of the wreck

displayed the least

colonisation of five the

zones however it also

displayed the most

variation in percentage

cover of individual

quadrat recordings

(figure 6).

3.2 Species Richness

Species richness was greatest

on the exterior forward wall of

the Bridge Wheel House. This

site had five different species

located within each individual

quadrat therefore had a

standard deviation of zero

(figure 7).

Horizontal zones of the wreck

that were surveyed, the roof of

the hanger and the aft deck

area, displayed the lowest

species richness of all surveyed

zones with an average of 2.08

(figure 7).

The horizontal zone also

displayed considerably

consistent species richness in

individual quadrat recordings

compared to the other zones

(figure 7).

Forward handrails of the HMNZS Canterbury displayed higher species richness than the aft handrails

(figure 8).

Vertical Surface

Port-Side Hull

Vertical Surface

Starboard-Side Hull

Vertical Surface

Stern Hull

Vertical Surface

Exterior Bridge Wall

Horozontal Surfaces0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Area

Av

era

ge

Pe

rce

nta

ge

Co

ve

r

Figure 6. Average percentage coverage/colonisation and standard deviation (displayed by error bars) of

the port-side hull, starboard-side hull, stern hull, exterior bridge wall and hanger roof and aft deck areas.

Derived from Zone surveys A-I and Q.

2.57

3

2.08

5

3

0.00

1.00

2.00

3.00

4.00

5.00

6.00

Port Hull Starboard Hull Horozontal

surfaces, Hanger

Roof & Aft Deck

Exterior Brigde

Wall

Stern hull

Areas

Avera

ge s

pecie

s r

ich

ness p

er

qu

ad

rat

Figure 7. Average species richness per quadrat in five different areas located on

the HMNZS Canterbury. Standard deviation is displayed by the error bars.



3.3 Macro Mobile Species, Presence and Average Size

All areas where visual surveys were

carried out had macro mobile species

present except for the middle funnel

(figure 9).

The only variation between average

sizes of individual species was

displayed by Pagrus auratus and

Scorpis lineolatus (Sweep). The

average size of P. auratus (Snapper)

was 15cm in the Gun Turret room and

an average length of 5cm in the Rear

Bunk room (figure 9).

S. lineolatus had an average size of

18.33cm in the Hanger and an average

length of 15cm recorded in the Rear

Bunk room (figure 9).

Parika scaber (Leather Jacket) and

Obliquichthys maryannae (Oblique

Swimming Triple fin) recorded

Figure 8. Species richness of Forward and Aft Handrails. Zones O and P,

method four; visual hand rail surveys.

0

2

4

6

8

10

12

14

16

18

20

Sweep, Scorpis

lineolatus

Leather Jacket, Parika

scaber

Big Eye, Pempheris

adspersa

Oblique Swimming

Triplefin, Obliquichthys

maryannae

Snapper, Pagrus

auratus

Fish

Avera

ge s

ize (

cm

)

Hanger

Middle funnel

Gun turret room

Bridge

Rear bunk room

Figure 9. Average lengths (cm) of macro mobile species derived from the surveys of zones J-N, method three; Visual

room surveys. Averages are calculated from mid points of size classes.

0

1

2

3

4

5

6

7

8

9

10

11

12

Forward Handrails Aft Handrails

Zone

Sp

ec

ies

Ric

hn

es

s



derived equal average size in different areas. P. scaber was recorded at having an average size of 15cm

in all three zones in which the species was present (figure 9).

Visual fish surveys showed that the Coris sandageri (Sandagers Wrasse) at a depth of 24 metres were,

on average, larger than individuals surveyed at 1.5 metres off the sea floor. This was also evident with P.

scaber (figure 10).

The average size of all species recorded at 24 metres appears to be larger, or close to the largest average

length when compared to other individuals of the same species, recorded at other depths. This is evident

by the average size of P. auratus at a depth of 24 metres being only 1.62 cm smaller than the average

size of snapper found 1.5metres off the sea floor (figure 10).

Figure 10. Average fish sizes (cm) of different species derived from surveys R, S and T, method six; visual fish

surveys.

The results from method six also show the average sizes of fish at 1.5 metres off the sea floor seem

consistently smaller than those recorded at other depths, with the exclusion of P. auratus and

Upeneichthyus lineatus (Goat fish) (figure 10).

3.4 Species Diversity

Using the Shannon species diversity index, it appeared zone R, the circumnavigation around the vessel

at 1.5 metres off the sea floor gave the highest species diversity at 1.808. An index value of 1.011was

calculated at 24 metres depth, and a value of 0.84 was derived from the 15 metre depth survey (table 2 &

figure 11).

0

5

10

15

20

25

30

35

40

45

Sna

pper

Pag

rus au

ratu

s

Goa

t Fish,

Upe

neichth

yus lin

eatus

Tarak

ihi,

Seriola la

land

i

Blue

Cod

, Par

aper

cis co

lias

Leather

Jack

et, P

arika s

caber

Triple

fin spp

Swee

p Sco

rpis line

olat

us

Big E

ye, P

emph

eris a

dspe

rsa

Spo

tty, N

otola

brus

celid

otus

San

dage

rs W

rase

, Cor

is san

dager

i

Por

ae, N

emada

ctylus

doug

lasii

Ban

ded

Wra

sse, N

otola

brus

fucico

la

Fish Species

Avera

ge s

ize (

cm

)

1.5 above sea floor

24 metres depth

15 metres depth



The highest species evenness was evident at Zone T, 15 metres depth, with a (H’/ln(S)) value of 0.921.

This zone also had the lowest species richness count (S= 3) and the least number of individuals (N= 6)

(table 2).

There is a huge variance between the numbers of individuals (N) present at each survey zone. The

highest number recorded was at zone S, 24 metres below the surface with 108 individuals recorded. The

lowest number of individuals recorded (N) occurred at Zone T, 15 metres below the surface with only 6

fish (table 2).

Table 2. Species richness, the number of individual fish, the Shannon Wiener Index of Diversity value and species

evenness value derived from each survey zone (S, T and V) in method six; visual fish surveys.

Zone Species

Richness (S) Number of

Individuals (N) Shannon Index of Diversity (H')

Species Evenness (h'/ln(S))

Zone T: 15m below the surface

3 6 1.011 0.921

Zone S: 24m below the surface

7 108 0.84 0.432

Zone R:1.5m off sea floor

10 94 1.808 0.785

The Rear bunk room was recorded in having the largest diversity with a Shannon Index of Diversity

value of 1.099 (table 3 & figure 12). The Rear Bunk Room also had the highest species evenness with a

(h'/ln(S)) value of 1.00 (table 3).

The most individual fish (N) were present in the bridge wheel house with a total of 33 individuals being

recorded (table 3).

The middle funnel had no macro mobile inhabitants recorded (table 3 & figure 12).

Table 3. Species richness, the number of individual fish, the Shannon Index of Diversity value and species evenness

value derived from each survey zone (J-N) in method four; visual room surveys.

Zone Species

Richness (S) Number of

Individuals (N)

Shannon-Wiener Index of

Diversity (H')

Species Evenness (h'/ln(S))

Zone J, Hanger 3 27 0.749 0.682

Zone K, Middle funnel 0 0 0 0

Zone L, Gun Turret room 2 3 0.637 0.918

Zone M, Bridge wheel house

2 33 0.305 0.439

Zone N, Rear Bunk Room

3 9 1.099 1



4.0Disscussion

4.1 Average Colonisation of Different Areas

The bridge exterior wall had the highest average colonisation with all quadrats containing 100 percent

coverage (figure 6). This may be due to the vertical angle of the surface, its position in the water

column, its location in reference to currents entering Deep Water Cove or a combination of these factors.

The bridge exterior wall faces approximately north-west towards the entrance to the cove therefore

gaining direct contact from currents entering Deep Water Cove. This would potentially provide a high

supply of juvenile planktonic larvae capable of colonising the wreck. The bridge exterior walls surface

would be favourable to colonising organisms as the available currents would circulate nutrient rich

water.

One factor that brought down the average percentage coverage of colonisation on the other vertical

areas; the starboard-side, port-side and stern hulls would be the anti-foul paint. This was present along

the first 2-4 metres of all transect lines of located on the hull. As the anti-foul paint is designed to

prevent fouling organisms inhabiting the hulls of vessels, little colonisation occurred in these regions.

This therefore brought down the average percentage of colonisation for all hull areas.

The stern hull faces an approximate direction of south-east. This location would receive little benefit

from currents entering the bay in comparison to the bridge exterior wall. A combination of this location

and the anti-foul paint could be responsible for the low average of colonisation on the stern hull.

4.2 Species Richness

Average species richness was highest on the exterior bridge wall. This could be due to it’s location in

the cove in relation to water currents, it vertical position in the water column and the lack of anti-foul

paint as mentioned above in section 4.1 average colonisation of different areas.

The forward and aft handrails, zones P and O showed little variation in the total species richness

however these zones should continue to be surveyed in future monitoring to illustrate any individual site

enhancement over time.

4.3 Macro Mobile Species, Presence and Average Size

No species were surveyed in the Zone K, the middle funnel (figure 9). This is possibly as the funnel was

considered to dangerous and unsafe to penetrate. Therefore the survey was completed with torch light

from the entrance. This was un-effective as the torch light did not reach the complete depth of the

middle funnel. It is recommended that this survey zone is eliminated from any future monitoring of the

wreck.

Parika scaber, also known as Leather Jackets were present in several survey zones under methods three

and six. The average size of the P.scaber recorded in method three was 15cm (figure 9) and the largest

average size of P.scaber surveyed in method six was 19.44cm in zone S, 24m below the surface (figure

10). These average sizes are considerably small however as P.scaber reaches a size of 45cm (Francis,

2001). These smaller sizes are also evident in the Pagrus auratus (Snapper) populations present on the

wreck with the largest average size of 15.37cm. P.auratus is able to reach sizes of up to 105cm.



With P. auratus and P. scaber both being dominant species present on the wreck, and with other

resident fish species being consistently small it is possible that theses individuals have inhabited the

artificial reef from a juvenile stage without migration from a near by natural reef. This is similar to past

studies carried out on ship wrecks in South East Florida USA, which have suggested that artificial reefs

like ship wrecks do not attract fish away from pre-existing natural reefs more that they create their own

diverse communities (Arena, Jordan & Spieler, 2007).

This theory could be further investigated with a comparative analysis of the results from Retter and

Newcombe’s survey of Deep Water Cove, pre-scuttling, October 2007. Average fish sizes of wreck

populations could be compared with average sizes of Deep Water Cove populations prior to the

scuttling. If the wreck populations are significantly smaller than the populations recorded by Retter and

Newcombe this could verify that the wreck is not attracting fish populations from surrounding natural

reefs.

However, if this theory is disproved, this could imply that fish from surrounding areas are migrating to

dense communities on the wreck as suggested by Gravitz in 2000. If this is the case, it is strongly

suggested that Deep Water Cove and near by areas are established as a marine protected area as fishing

pressure may be exerted on the artificial reef that is the HMNZS Canterbury. This could potentially over

exploit fish populations in this area as suggested by Grossman, Jones & Seaman in 1997.

4.4 Species Diversity

The largest species diversity that was recorded in method six was present at zone R, 1.5 metres off the

sea floor with an H’ value of 1.808. Zone T, 15 metres below the surface had the second highest H’

value of 1.011. Zone S has a score of 0.84 all though it has the highest number of individuals recorded

and species richness over twice that of zone T. The lower score is due to a low species evenness which

may be considered as skewing the resulting species diversity value.

The greater number of individual fish present at 1.5 metres off the bottom and at a 24 metre depth level

is an indication that the HMNZS Canterbury is acting successfully as an artificial reef and attracting

fish. This is emphasised by a presence of only six individual fish being recorded in zone T, a level of 15

metres below the surface.

The greatest species diversity in method three was evident in zone N, the rear bunk room. The H’ score

of 1.099 is partially due to the high species evenness of 1.00. Zone J, the hanger had the most

individuals present and also shared the highest species richness with rear bunk room. This would

possibly be due to the hanger’s large size and easy access from outside the wreck. The hanger also had

many dark corners that would offer protection from possible predators.

4.5 Conclusion

Colonisation of the wrecks surfaces has developed since its scuttling with some exposed areas

completely colonised by encrusting organisms and some areas partially colonised at the time of

surveying. Areas facing the entrance of the cove generally have higher percentage cover than those

facing the land. This may be due to prevailing currents in the cove.

Fish are present on the wreck with large numbers present around the sea floor and main deck level. It is

possible that they are local populations to the wreck and have not migrated from other natural reefs. This

is supported by the small average sizes of several species recorded throughout the survey. Further

studies would need to be completed to verify this theory.



It is suggested that Deep Water Cove and surrounding areas are converted into a marine protected area

to guard commercially and recreationally targeted fish stocks in the area once they reach legal size. This

is important to conserve the community development of the HMNZS Canterbury.

No large predatory fish were recorded on the wreck at this stage though large predatory fish weren’t

present on the Rainbow Warrior until one year after the scuttling (Muherami, 2004).

Various amounts of diversity and species richness are present at different areas of the wreck however it

is not possible to say at this stage if any climax communities have been reached.

4.6 Future Monitoring

The next surveys of the monitoring plan of the HMNZS Canterbury are scheduled for November 2008.

This will consist of a repetition of July 2008 survey as well as a repetition of Retter and Newcombe’s

survey of surrounding areas in Deep Water Cove, October 2007.

The repetition of Retter and Newcombe’s survey is an important component to the monitoring plan of

the HMNZS Canterbury. The surveying of the surrounding areas is planned to indicate any positive

and/or negative impacts of the wreck to Deep Water Cove.



5.0 References

Arena. P., Jordan. L., Spieler. R. (2007). Fish assemblages on sunken vessels and natural reefs in south

east Florida, U.S.A. Springer Science and Business Media B.V. Dordrecht: Netherlands

BBS Divers (n.d) Diving down the corridor. Retrieved August 15, 2008 from

http://www.bbsdivers.co.nz/site/images/129255.jpg

Canterbury Charitable Trust. (2008). HMNZS Canterbury. Retrieved, June, 5, 2008, from

www.canterburywreck.co.nz

Dive HQ Bay of Islands (n.d) View from the Bridge. Retrieved August 15, 2008 from

http://www.divenz.com/images/canterbury_dive.JPG

Enderby. J. and Enderby T. (2002). Diving and Snorkelling New Zealand. Lonely Planet Publication Pty

Ltd. Footscray: Australia

Far North District Council (2008) Retrieved July 17, 2008 from

http://www.fndc.govt.nz/misc/ifrigatecanterbury.asp

Francis. M (2001) Coastal Fishes of New Zealand. Reed Publishing (NZ) Ltd. Auckland, New Zealand.

Grace, R (2007) Rainbow Warrior - Twenty Years after the Big Bang! Retrieved June 5, 2008 from

http://www.marinenz.org.nz/index.php/the_undersea_world/roger_grace_archive/rainbow_warrior_-

_twenty_years_after_the_big_bang

Gravitz, L (2000). The double-edged lure of man-made reefs. Christian Science Monitor, 92(177), 16.

Retrieved August 15, 2008 from EBSCO Search Host Premier

Grossman, G. D., Jones G. P., Seaman, Jr, W. J (1997) Do Artificial Reefs Increase Regional Fish

Production? A Review of Existing Data, American Fisheries Society, 22(4) 17-23. Retrieved August

15, 2008 from Google Scholar.

Guinness, S., Betty, G. & Kennedy. (2005). Colonisation of the artificial reef: Taioma. Bay of Plenty

Polytechnic: New Zealand.

Muherami, J., (Producer/Director). (2004). Life in the Graveyards of the Pacific. [Documentary].

Australia: Big Fish Productions.

Middleton, J. (2005). All hands on deck to farewell a grand dame. New Zealand Herald. Retrieved

March 05, 2005 from

http://www.nzherald.co.nz/organisation/story.cfm?o_id=105&ObjectID=10113651

Military Images (2006) HMNZS Canterbury. Retrieved August 15, 2008 from

http://www.militaryimages.net/photopost/data/592/New_Zealand_Navy_-

_frigate_HMNZS_Canterbury_-_3.jpg



Northland Fishing (2008) Map. Retrieved August 08, 2008 from http://northlandfishing.net.nz/map2.jpg

Picasa Web (2008) Map. Retrieved August 08, 2008 from

http://picasaweb.google.com/terawhitimarae/TheExCanterburySinkingManawahunaRoheDeepWaterCo

ve/photo#5136381985908414674

Retter, M. & Newcombe, H. (2007). The scuttling of the HMNZS Canterbury. Bay of Plenty

Polytechnic. New Zealand.

Ross-Watt, T., Clarke P., R. (1997) Colours of the Rainbow. Bay of Plenty Polytechnic: New Zealand

Schaffler, L. (2007, May 28). Waikato's happy grave. Retrieved August 15, 2008, from

http://www.tradeaboat.co.nz/ArticleDetails.aspx?Ne=145&N=4294967237&item=447&sid=11AFA

EE5E973

Stewart Island Nov 2004 (2004). Canterbury in the distance. Retrieved August 15, 2008 from

http://staples-moon.net/bruce/pics/rakiura/140024.jpg

Tapeka (n.d) Swimming though a hole. Retrieved August 15, 2008 from

http://www.tapeka.com/HMNZS%20Waikato%20Sunk2.jpg

Vanuatu Tourism Office. (n.d) Colonial History of Vanuatu – President Coolidge. Retrieved August 15,

2008 from

http://www.vanuatutourism.com/vanuatu/export/sites/VTO/en/history/president_coolidge.html



6.0 Appendix

Scientific name Common Name

Balanus spp. Barnacle

Carpophylum flexuosum

Carpophylum maschlocarpum

Cliona celata

Coris sandageri Sandagers Wrase

Corynactis haddoni jewel anemone

Demadactylus douglasii Porae

Ecklonia radiata

Lithothamnion spp.

Notolabrus celidotus Spotty

Notolabrus fucicola Banded Wrasse

Obliquichthys maryannae Oblique Swimming Triplefin

Pagrus auratus Snapper

Palaemon affinis Glass Shrimp

Parapercis colias Blue Cod

Parika scaber Leather Jacket

Pecten novaezelandiae Scallop

Pempheris adspersa Big Eye

Pomatoceros spp.

Scorpis lineolatus Sweep

Seriola lalandi Tarakihi

Talochlamys zelandiae Fan Shell

Upeneichthys lineatus Goat Fish

Yet to be identified Brown Sponge

Yet to be identified green hydroid

Yet to be identified Orange anemone

Yet to be identified tube annelid sp.

Yet to be identified red algae

Yet to be identified black and white barnacle

Yet to be identified White Striped Anemone

Yet to be identified Green algae



New Name %

Cover

C 100.00% PORT

D 62.00%

E 93.33%

Ave 85.11% Vertical Surface - Port-Side Hull

STDEV 20.29%

F 83.00% STARBOARD

G 83.00%

H 78.75%

Ave 81.58% Vertical Surface - Starboard-Side Hull

STDEV 2.45%

Average 83.35%

STDEV 13.07%

B 63.33%

Vertical Surface - Stern Hull

I 100.00%

Vertical Surface - Bridge Wall

81.67%

25.93%

Total

Average 82.93%

Total STDEV 14.79%

Circumnavigations average spp size

1.5 24 15

Snapper Pagrus auratus 15.37 13.75

Goat Fish, Upeneichthyus lineatus 17 15

Tarakihi, Seriola lalandi 5

Blue Cod, Parapercis colias 21.67

Leather Jacket, Parika scaber 8.33 19.44 18.33

Triplefin spp 5

Sweep Scorpis lineolatus 5 15

Big Eye, Pempheris adspersa 5

Spotty, Notolabrus celidotus 5 15 15

Sandagers Wrase, Coris sandageri 21.67 40

Porae, Nemadactylus douglasii 15

Banded Wrasse, Notolabrus fucicola 35



Average Size

Fish Hanger Middle funnel

Gun turret room Bridge

Rear bunk room

Sweep, Scorpis lineolatus 18.33333 15 Leather Jacket, Parika scaber 15 15 15 Big Eye, Pempheris adspersa 5 Oblique Swimming Triplefin, Obliquichthys maryannae 5 5 Snapper, Pagrus auratus 15 5

Species Richness

Zone Number of Species Total Ave Species STDEV

Port Hull 10 2.57 1.65

Starboard Hull 8 3 1.83

Handrail port 10

Handrail starboard 11

Forward Handrails 11

Aft Handrails 10

Horizontal surfaces, Hanger Roof & Aft Deck 9 2.08 0.95

Exterior Bridge Wall 5 5 0

Stern hull 6 3 2

monitoring of the hnmzs canterbury artificial reef

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