Reef Surveys at Twelve Apostles Marine National Park and The Arches Marine Sanctuary

76 Pages·2010·15.95 MB·English

p a r k s v i c t o r i a t e c h n i c a l s e r i e s
number 56
reef surveys at twelve apostles
marine national park and
the arches marine sanctuary
M. Edmunds, P. Pickett and A. Judd
June 2010
© Parks Victoria
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First published 2010
Published by Parks Victoria
Level 10, 535 Bourke Street, Melbourne Victoria 3000
Opinions expressed by the Authors of this publication are not necessarily those of Parks
Victoria, unless expressly stated. Parks Victoria and all persons involved in the preparation and
distribution of this publication do not accept any responsibility for the accuracy of any of the
opinions or information contained in the publication.
Author(s):
Matt Edmunds – Principal Marine Ecologist, Australian Marine Ecology Pty. Ltd.
Penny Pickett – Marine Ecologist, Australian Marine Ecology Pty. Ltd.
Anthony Judd – Marine Ecologist, Australian Marine Ecology Pty. Ltd.
National Library of Australia
Cataloguing-in-publication data
Includes bibliography
ISSN 1448-4935
Citation
Edmunds, M., Pickett, P. and Judd, A. (2010) Reef Surveys at Twelve Apostles Marine
National Park and The Arches Marine Sanctuary. Parks Victoria Technical Series No 56.
Parks Victoria, Melbourne.
Printed on environmentally friendly paper
Parks Victoria Technical Paper Series No. 56

Reef Surveys at Twelve Apostles Marine
National Park and The Arches Marine
Sanctuary

Matt Edmunds
Penny Pickett
Anthony Judd

Australian Marine Ecology Pty Ltd

June 2010
Parks Victoria Technical Series No. 56 Twelve Apostles Reef Survey
EXECUTIVE SUMMARY
The initial survey objective was to expand the Parks Victoria Subtidal Reef Monitoring
Program (SRMP) to provide baseline biological information from the Twelve Apostles Marine
National Park and The Arches Marine Sanctuary. The SRMP monitoring program uses
standardised underwater visual census techniques for long-term monitoring of reef biota
throughout Victoria and elsewhere in southern Australia, undertaken by divers. From 2003 to
2005, it was found that diving surveys were not going to be feasible in this region due to the
high exposure of the coastline to the prevailing weather, turbulent seas and diveable reefs
which were often too close to shoreline cliffs. Only one site was successfully surveyed using
the SRMP methods during this period.
During the same period of time, substantial advancements were made in the technology and
techniques for surveying the flora and fauna of deep marine habitats. These developments
included the use of easily deployed remotely operated vehicles (ROV) with sophisticated
underwater navigation systems, as well as developed protocols for the collection of biological
data from the underwater video on the ROV. These methods were implemented with success
at the Port Phillip Heads Marine National Park. Thus, with little prior success to undertake
SRMP monitoring within the Twelve Apostles Marine National Park and The Arches Marine
Sanctuary, the focus of this project was altered to use an ROV and the associated methods
to describe the biota of deeper habitats within the parks.
Seven (7) sites in the Twelve Apostles Marine National Park and four (4) sites in and near
The Arches Marine Sanctuary were surveyed using a standardised quantitative ROV video
survey technique. These were surveyed between June and August 2006 and ranged in depth
from 18 to 45 m depth. A total of 924 still-frames were captured from the video footage and
processed to provide percent cover abundance data on plants and animals attached to the
reef (sessile biota), including seaweeds, sponges, corals and ascidians (sea squirts).
A multivariate statistical analysis indicated there were approximately seven major
assemblage types in the region, with intergrades between these assemblage types also
occurring. The shallower sites (18-25 m depth) were dominated by seaweeds with a strong
component of larger brown algae, particularly the kelp species, Ecklonia radiata, thallose red
algae and encrusting coralline algae. The abundance of the brown algae decreased with
depth, with the canopy thinning to form a Ecklonia kelp ‘park’ at approximately 30-35 m
depth. The larger brown alga, Seirococcus axillaris, was a small but notable component of
the community at The Arches Marine Sanctuary sites, but was not present on shallower reefs
sites within the Twelve Apostles Marine National Park. The thallose red algal species were
similar to those observed on shallow subtidal reefs in Victoria, including: Phacelocarpus
peperocarpus, Plocamium mertensii, Gelidium asperum and Sonderopelta coriacea. The
abundance of sessile invertebrates on the reef tops increased with depth, particularly the
abundances of the isidid gorgonian, Pteronisis spp., erect sponges, and the large hydroid
fan, Solanderia fusca. At the two deepest sites surveyed; both 45 m in depth; contained
assemblages dominated by a variety of sponge colonies, bryozoans, coral and ascidians,
with only a very low abundance of seaweed.
As observed elsewhere in Victoria, the benthic assemblages were heterogeneous or patchy,
within each site. These patches of different assemblages were generally associated with
obviously different microhabitat structures, such as reef tops (horizontal surfaces), ledge
edges, vertical walls and caverns under ledges. Assemblages within these microhabitats
were replicated between sites. This indicated that assemblage structure is strongly
influenced or determined by environmental conditions.
An important outcome from this study was the provision and archiving of data and
information on existing conditions at the Twelve Apostles and The Arches marine protected
areas. The surveys undertaken can be replicated in the future to monitor the biological
condition of these areas over time. In addition, the data obtained is comparable with surveys
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Parks Victoria Technical Series No. 56 Twelve Apostles Reef Survey
from other deep reefs in Victoria, including Port Phillip Heads Marine National Park and
Wilsons Promontory Marine National Park, facilitating a better understanding of the ecology
of deep reefs in Victoria.
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Parks Victoria Technical Series No. 56 Twelve Apostles Reef Survey
CONTENTS
EXECUTIVE SUMMARY............................................................................................II
CONTENTS..............................................................................................................IV
INDEX OF FIGURES AND TABLES........................................................................VI
1 INTRODUCTION..................................................................................................1

1.1 Marine Protected Areas in the Twelve Apostles Region..................................................1

1.1.1 Twelve Apostles Marine National Park....................................................................................1

1.1.2 The Arches Marine Sanctuary.................................................................................................1

1.2 Subtidal Reef Monitoring Program..................................................................................2

1.3 Marine Habitat Mapping..................................................................................................2

1.4 Deep Reef Biota Surveys................................................................................................2

1.5 Objectives.......................................................................................................................3
2 METHODS...........................................................................................................4

2.1 Survey Techniques.........................................................................................................4

2.2 Diving Survey – Underwater Visual Census....................................................................5

2.2.1 General Methods......................................................................................................................5

2.2.2 Method 1 – Mobile Fishes and Cephalopods...........................................................................7

2.2.3 Method 2 – Invertebrates and Cryptic Fishes..........................................................................7

2.2.4 Method 3 – Macroalgae...........................................................................................................8

2.2.5 Method 4 – Macrocystis...........................................................................................................8

2.3 Towed Video Survey - Habitat Mapping..........................................................................8

2.4 ROV Survey – Underwater Video Census.....................................................................10

2.4.1 ROV Survey Sites..................................................................................................................10

2.4.2 ROV Equipment.....................................................................................................................10

2.4.3 ROV Transects.......................................................................................................................13

2.5 Quantitative Video Analysis...........................................................................................16

2.5.1 Video Frame Capture.............................................................................................................16

2.5.2 Points-Cover Estimation.........................................................................................................16

2.5.3 Classification..........................................................................................................................18

2.5.4 Points Standardisation and Data Pooling..............................................................................20

2.5.5 Data Summaries....................................................................................................................20

2.5.6 Taxonomic Richness and Diversity........................................................................................20

2.5.7 Community Analysis...............................................................................................................21

2.5.8 Database................................................................................................................................21
3 RESULTS ..........................................................................................................22

3.1 Regional Flora and Fauna.............................................................................................22

3.2 Site Observations..........................................................................................................23

3.2.1 Twelve Apostles MNP, Site 3801, 45 m Depth.....................................................................23

3.2.2 Twelve Apostles MNP, Site 3802, 45 m Depth.....................................................................26

3.2.3 Twelve Apostles MNP, Site 3803, 35 m Depth.....................................................................29

3.2.4 Twelve Apostles MNP, Site 3804, 45 m Depth......................................................................32

3.2.5 Twelve Apostles MNP, Site 3805, 27-45 m Depth.................................................................34

3.2.6 Twelve Apostles MNP, Site 3806, 37 m Depth......................................................................36
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Parks Victoria Technical Series No. 56 Twelve Apostles Reef Survey

3.2.7 Twelve Apostles MNP, Site 3807, 20 m Depth......................................................................39

3.2.8 The Arches MS, Site 3831, 18 m Depth................................................................................42

3.2.9 The Arches MS, Site 3832, 17-20 m Depth...........................................................................45

3.2.10The Arches MS, Site 3833, 25 m Depth................................................................................48

3.2.11The Arches MS, Site 3834, 27 m Depth................................................................................50

3.3 Site Comparisons..........................................................................................................52

3.4 Assemblage Structures.................................................................................................57

3.5 Assemblage Distributions..............................................................................................62
ACKNOWLEDGMENTS...........................................................................................63
REFERENCES.........................................................................................................64

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Parks Victoria Technical Series No. 56 Twelve Apostles Reef Survey
INDEX OF FIGURES AND TABLES
FIGURES
Figure 1. Locations of the Twelve Apostles Marine National Park and The Arches

Marine Sanctuary..................................................................................................... 1
Figure 2. Location of the ROV and diving survey sites at Twelve Apostles Marine

National Park and The Arches Marine Sanctuary.................................................... 6

Figure 3. Biologist-diver with transect reel............................................................................. 8
Figure 4. The cover of macrophytes is measured by the number of points intersecting

each species on the quadrat grid............................................................................. 8

Figure 5. Underwater video towfish....................................................................................... 9
Figure 6. Location of the towed-video transects (red lines) at the Twelve Apostles

Marine National Park..............................................................................................10
Figure 7. Remotely operated vehicle (ROV) and tether. Scanning sonar and sonar

tracking devices are mounted on top of the vehicle.................................................11
Figure 8. Screen capture from the scanning sonar: a reef wall is 6 m in front of the ROV

and extends 24 m to the left and right.....................................................................12

Figure 9. Remotely operated vehicle (ROV) instrument system............................................12

Figure 10. Remotely operated vehicle instrument station.....................................................13

Figure 11. Location of ROV tracks for reef surveys at eastern Twelve Apostles MNP..........14

Figure 12. Location of ROV tracks for reef surveys at western Twelve Apostles MNP..........15
Figure 13. Location of ROV tracks for reef surveys at The Arches Marine Sanctuary,
26th August 2006.....................................................................................................15
Figure 14. Example screen of the BioPoints software for determining points-cover

abundance of sessile organisms.............................................................................17
Figure 15. Standardised sponge morphological types, after Bell and Barnes (2001).

Characteristic taxa are given where possible..........................................................19

Figure 16. Site 3801: ‘Taco’ sponge.....................................................................................24

Figure 17. Site 3801: Hydroid fan, Solandaria fusca (right), and bryozoan colony (left)........24

Figure 18. Site 3801: Example frames used for abundance analysis....................................25
Figure 19. Site 3802: Typical assemblage with a variety of erect and encrusting
sponges, gorgonian fans, Mopsella zimmeri (yellow wiry strictures in centre)

and ascidian, Pyura spinifera (stalked structure in centre)......................................26

Figure 20. Site 3802: Hydroid fan, Solandaria fusca, and arborescent orange sponge.........27

Figure 21. Site 3802: Stony coral, Plesiastria versipora, colonies.........................................27
Figure 22. Site 3802: Example frames used for abundance analysis, Twelve Apostles

MNP.......................................................................................................................28

Figure 23. Site 3803: Isidid gorgonian, Pteronisis sp. (yellow)..............................................30
Figure 24. Site 3803: Encrusting coralline algae and fleshy thallose red algae. Solitary

ascidians, Herdmania momus, are present upper left, Twelve Apostles MNP.........30
Figure 25. Site 3803: Example frames used for abundance analysis, Twelve Apostles

MNP.......................................................................................................................31
Figure 26. Site 3804: Thallose red algae, predominantly, Pterocladia lucida. Patches of

pink encrusting coralline algae are also visible.......................................................32
Figure 27. Site 3804: Example frames used for abundance analysis, Twelve Apostles

MNP.......................................................................................................................33
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Parks Victoria Technical Series No. 56 Twelve Apostles Reef Survey
Figure 28. Site 3805: Mixed red algal and sponge assemblage in foreground. There is
a southern rock lobster, Jasus edwardsii, present in the crevice to the right,

Twelve Apostles MNP.............................................................................................34
Figure 29. Site 3805: Example frames used for abundance analysis, Twelve Apostles

MNP.......................................................................................................................35

Figure 30. Erect ruffled grey sponge with central part of colony missing...............................37
Figure 31. Site 3806: Cup sponge with thallose red alga, likely to be Callophyllus

rangiferina, Twelve Apostles MNP..........................................................................37
Figure 32. Site 3806: Example frames used for abundance analysis, Twelve Apostles

MNP.......................................................................................................................38
Figure 33. Site 3807: Southern rock lobster, Jasus edwardsii, foraging amongst
thallose red algae. Brown kelp, Ecklonia radiate, is in the background, Twelve

Apostles MNP.........................................................................................................40
Figure 34. Site 3807: Typical reef top habitat with kelp, Ecklonia abundance, thallose
red algae and pink encrusting coralline algae. Note the strong wave surge

which sweeps the kelp fronds over the reef top, Twelve Apostles MNP..................40
Figure 35. Site 3807: Example frames used for abundance analysis, Twelve Apostles

MNP.......................................................................................................................41
Figure 36. Site 3831: Thallose red alga, Melanthallia obtusata, and brown kelp,

Ecklonia radiate, The Arches MS............................................................................43
Figure 37. Site 3831: Reef wall fauna under upper ledges of wall including encrusting

and massive sponges and gorgonian fans, Mopsella spp., The Arches MS............43

Figure 38. Site 3831: Example frames used for abundance analysis, The Arches MS. ........44

Figure 39. Site 3832: Example frames used for abundance analysis, The Arches MS. ........46

Figure 40. Site 3833: Example frames used for abundance analysis, The Arches MS. ........49

Figure 41. Site 3834: Example frames used for abundance analysis, The Arches MS. ........51
Figure 42. Differences in community structure between sites in the Twelve Apostles
Marine National Park and The Arches Marine Sanctuary. Site medioids from
MDS ordination of all frames (two dimensions, Kruskall Stress = 0.17). Site
medioids were determined as the frame with the smallest Bray-Curtis distance

from the site centroid (means of species abundances)...........................................56
Figure 43. Relative variations in community structures in sampled frames within and
between sites. Magenta symbols indicate frames sampled from that site.

Twelve Apostles Marine National Park....................................................................58
Figure 44. Relative variations in community structures in sampled frames within and
between sites at The Arches Marine Sanctuary. Magenta symbols indicate
frames sampled from that site. Multidimensional scaling ordination of all

frames (two dimensions, Kruskall Stress = 0.17)....................................................59
Figure 45. Classification of frames by assemblage type based on recurring clusters

between sites (Figures 32 and 33)..........................................................................59

TABLES
Table 1. Site survey details for the Twelve Apostles Marine National Park and The

Arches Marine Sanctuary......................................................................................... 7
Table 2. Site details for towed-video surveys in the Twelve Apostles Marine National

Park......................................................................................................................... 9
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Parks Victoria Technical Series No. 56 Twelve Apostles Reef Survey
Table 3. Standardised index of sponge classification categories for sponge
morphological types, i.e. type of shapes, structures and forms, after Bell and

Barnes (2001). Numbers refer to the coding system...............................................20
Table 4. Site 3832: Abundance of fishes (per 1000 m2) at The Arches Marine

Sanctuary, diving survey, April 2004.......................................................................47
Table 5. Site 3832: Percentage cover of algae at The Arches MS, diving survey, April

2004.......................................................................................................................47
Table 6. Site 3832: Abundance of invertebrates at The Arches, diving survey, April

2004.......................................................................................................................47
Table 7. Quantitative ROV data (BioPoints frames): percent cover of sessile plants and
animals at surveyed sites in the Twelve Apostles Marine National Park. Empty

cell indicates taxon not present...............................................................................52
Table 8. Quantitative ROV data (BioPoints frames): percent cover of sessile plants and
animals at surveyed sites in The Arches Marine Sanctuary. Empty cell

indicates taxon not present.....................................................................................55

Table 9. Diversity statistics for BioPoints frames abundance data pooled by site.................56
Table 10. Mean taxon abundances for identified assemblages in the Twelve Apostles

Marine National Park and The Arches Marine Sanctuary........................................60
Table 11. Diversity statistics for frames abundances pooled by assemblage type. Hill’s
N2 statistic is an indicator of the number of dominant species in the

assemblage............................................................................................................62
Table 12. Percent occurrence of different assemblage types at each site based on

classified frames.....................................................................................................62

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