Marine Video Survey of Western Port

Transcription

1 Marine Video Survey of Western Port No. 176 October 2012

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3 Sean Blake, David Ball, Allister Coots and Tim Smith April 2013 Fisheries Victoria Department of Primary Industries

4 If you would like to receive this information/publication in an accessible format (such as large print or audio) please call the Customer Service Centre on: , TTY: , or Copyright The State of Victoria, Department of Primary Industries, This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act Preferred way to cite: Blake, S., Ball, D., Coots, A., Smith, T. (2013) Marine video survey of Western Port. Fisheries Victoria Technical Report No. 176, 53 pages. Department of Primary Industries, Queenscliff, Victoria, Australia. ISSN ISBN (Print) Author Contact Details: Sean Blake Fisheries Management & Science, Fisheries Victoria PO Box 114, Queenscliff Victoria 3225 Authorised by the Victorian Government, 2a Bellarine Hwy, Queenscliff, Victoria 3225 Printed by DPI Queenscliff, Victoria Published by the Department of Primary Industries. General disclaimer This publication may be of assistance to you but the State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication. ii

5 Executive Summary This project was part of a Department of Sustainability and Environment (DSE) funded program to model shallow marine habitats along the Victorian coastline from LiDAR (Light Detection and Ranging) and multibeam sonar bathymetry data. The overall project aim was to continue to build an understanding of Victoria s marine environment by filling priority data gaps in the development of a statewide marine habitat model. The current project aimed to collect information on seabed topography, habitat and biota with underwater video systems for future habitat and biota modelling at Western Port. The video transects presented in this report were surveyed in two stages. Video transects at the western and eastern entrances were surveyed between October 2009 and March 2011 as part of a Statewide LiDAR ground-truthing program. Further video transects targeting Western Port, including rhodoliths near the eastern entrance, were surveyed between December 2011 and March The combined video data for all Western Port consisted of 88 video transects with a total length of 41 km and 37,187 video data points. The substrate types surveyed by the towed video consisted of 81% sediment (100% sediment), 17.5% patchy reef/sediment (combined mixed reef and sediment classes) and 1.5% reef (100% reef). Sediment was the dominant substrate type and the sediment texture consisted of 55% sand, 24% shelly sand, 19% silt and 2% gravel/pebble. The texture of the reef observations (including patchy reef/sediment classes) was 95% low profile with 5% high profile. Biota were present on 73% of the video records and consisted of 53% macroalgae, 37% seagrass and 31% sessile invertebrates (more than one biota class could be recorded at each video point). Mixed red algae were present in 82% of the macroalgae records and occurred throughout Western Port. Species of Caulerpa were present in 37% of the macroalgae records with the most extensive beds occurring in the Rhyll Segment. Other mixed green algae were present in 3% of the macroalgae records. Mixed brown algae were present in 33% of the macroalgae records and were typically associated with areas of reef. Seagrass species were common throughout Western Port and often formed beds of mixed species. Zostera spp. were present in 43% of the seagrass records, distributed throughout Western Port at depths of m, although it was mostly at depths <5 m and was only observed at depths >7.7 m in the western entrance. Halophila australis was present in 42% of the seagrass records at depths of m and was also present throughout Western Port. Amphibolis antarctica was present in 45% of the seagrass records at depths of m and was restricted to the eastern and western entrances. Sponges were present in 81% of the sessile invertebrate records and occurred on sand and reef bottom across Western Port. Ascidians were present in 33% of the sessile invertebrate records and occurred on reef and shelly sediment in the Lower and Upper North Arms and on silt in the Rhyll Segment. Bryozoans were present in 16% of the sessile invertebrate records and occurred on reef in the Lower and Upper North Arms and on silt in the Rhyll Segment. Sea pens were present in 15% of the sessile invertebrate records and occurred on shelly sand in the Lower and Upper North Arms and on silt in the Rhyll Segment. Rhodoliths were observed distributed over an area of approximately 0.5 km 2 near the eastern entrance and depths ranged from m. Few fish were observed during a stereo video deployment at the rhodolith beds and the species were limited to smooth toadfish, globefish and goatfish. iii

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7 Table of Contents Executive Summary... iii Introduction... 1 Objectives... 1 Material and Methods... 3 Study Site... 3 Video Transects... 3 Underwater Video... 3 Single-beam Sounder... 3 Stereo Video... 3 Data Analysis... 3 Video Classification... 3 Stereo Video... 4 Results and Discussion... 7 Underwater Video... 7 Substrate and Biota Distribution... 8 Substrate... 8 Biota... 8 Stereo Video at Rhodolith Site Acknowledgments References Appendix 1. Video Transect Locations Appendix 2. Video Observations Western Entrance Segment Lower North Arm Upper North Arm Corinella Segment Rhyll Segment Appendix 3. Video Still Image Locations v

8 List of Tables Table 1. Marine video habitat classification scheme Table 2. Number of video points in each geographic segment Table 3. Total number and depth ranges for video observations of Zostera spp Table 4. Mean fish TiV, MaxN and length for all species observed at all sites in rhodolith beds with stereo video List of Figures Figure 1. Study area and LiDAR/Multibeam bathymetry survey extents Figure 2. Towed video frame with live view camera and high definition camcorder (top left, top right), on-board integrated video-recording equipment (bottom left) and USBL Tracklink mounting pole with hydrophone (bottom right) Figure 3. Western Port segments and video transect survey locations Figure 4. Distribution of substrate types Figure 5. Distribution of sediment types Figure 6. Distribution of high and low profile reef (including patchy reef/sediment records) Figure 7. Distribution of mixed brown algae, E. radiata and Cystophora spp Figure 8. Distribution of mixed green algae and Caulerpa spp Figure 9. Distribution of mixed red algae Figure 10. Distribution of seagrass species Figure 11. Distribution of bryozoans and ascidians Figure 12. Distribution of sponges, sea pens and rhodoliths Figure 13. Video transect locations Western Entrance Segment Figure 14. Video transect locations Lower North Arm Segment Figure 15. Video transect locations, Upper North Arm and Corinella (north) Segments Figure 16. Video transect locations, Rhyll and Corinella (south) Segments Figure 17. Underwater video still images Western Entrance segment (Images 25 32) Figure 18. Underwater video still images Lower North Arm (Images 33 34) Figure 19. Underwater video still images Upper North Arm (Images 17 18) Figure 20. Underwater video still images Corinella segment Figure 21. Underwater video still images Rhyll segment (Images 41 43) Figure 22. Video still locations Western Entrance Segment Figure 23. Video still locations Lower North Arm Segment Figure 24. Video still locations Upper North Arm and Corinella (north) Segments Figure 25. Video still locations Rhyll and Corinella (south) Segments (see also Figure 26) Figure 26. Video still locations at rhodolith area north of San Remo within Rhyll segment vi

9 Introduction The Department of Sustainability and Environment (DSE) commissioned an airborne LiDAR (Light Detection and Ranging) bathymetry survey of the Victorian coast as part of the Future Coasts program during A seafloor digital elevation model (DEM) to depths of approximately 30 m was produced from the LiDAR survey. A consultant was engaged by DSE to model marine habitats (substrata and biota) with the LiDAR reflectivity and DEM data (Worley Parsons et al. 2010). The Department of Primary Industries Fisheries Research Branch (FRB) was commissioned by DSE to design and implement a marine video survey program to support development and an accuracy assessment of the LiDAR-derived habitat models. The outcomes of this video program were presented in Blake et al. (2012). The airborne LiDAR survey was unable to record depths in the deeper regions of Western Port due to turbid water. Consequently, Western Port was not included in the initial LiDAR marine habitat modelling (Worley Parsons et al. 2010). A vessel based multibeam bathymetry survey of Western Port was subsequently commissioned by DSE in 2009 to provide data over some of the deep areas missed by the LiDAR program (Figure 1). The current study extended the statewide marine LiDAR video program (Blake et al. 2012) to survey the Western Port region, including the multibeam bathymetry survey area. The video survey also targeted rhodolith beds at the eastern entrance to Western Port described by Harvey and Bird (2008) as this is the only known shallow rhodolith system in Victoria. The recent report Understanding the Western Port Environment. A summary of current knowledge and priorities for future research (Melbourne Water 2011) identified determining linkages between fish and habitats as a high priority research need for Western Port. While fish assemblages in seagrass (Zostera spp.) and mangrove habitats are relatively well studied there are a number of other potentially important fish habitats in Western Port about which little is known, both in terms of their intrinsic biodiversity value and also their potential as alternative habitats. In response to this research need a separate FRB study for Melbourne Water is investigating the specificity of fish-habitat relationships in Western Port to determine the resilience of fish populations to habitat loss through the use of alternative habitats (i.e. Amphibolis antarctica, Caulerpa spp., bryozoan isolates and sponge/ascidian beds). The fish-habitat relationship study is deploying stereo-video systems to record fish populations across different habitats in Western Port. The current study also deployed these stereo-video systems at the rhodolith beds during the video habitat survey to provide complementary information on this little known system. Objectives The overall project aim was to continue to build an understanding of Victoria s marine environment by filling priority data gaps in the development of a statewide marine habitat model. The project objectives were to: Design and implement a video survey program to target key marine habitats in Western Port covered by the LiDAR and multibeam bathymetry surveys Classify the marine video data with a consistent habitat classification scheme suitable for developing and testing the accuracy of LiDAR and multibeam derived habitat models Investigate the distribution of rhodolith beds near San Remo and associated fish communities. 1

10 Figure 1. Study area and LiDAR/Multibeam bathymetry survey extents. 2

11 Material and Methods The Western Port seabed was surveyed with a towed underwater video system to depths of approximately m. The video system was used to collect information on seabed topography, habitat and biota. Study Site The Western Port study area is shown in Figure 1. The study area encompasses the Victorian Embayments Western Port bioregion (IMCRA 1998). The rhodolith area at the eastern entrance to Western Port was previously described by Harvey and Bird (2008). Video Transects Video transect locations at the entrances to Western Port were selected in consultation with DSE s marine LiDAR modelling consultant (Worley Parsons). Transect locations for the remainder of Western Port were selected in conjunction with Deakin University using the same criteria and additional multibeam bathymetry data. The video transects were selected having regard to the following (Worley Parsons et al. 2010): LiDAR Digital Elevation Model (and subsequent multibeam DEM) Existing mapping and knowledge of shallow habitats Adequate representation of each of the LiDAR modeling regions for substrata/biota model training and classification Adequate representation of observable attributes within survey areas e.g. substrata, biota, depth range, exposure to prevailing weather/energy conditions Optimal placement of video transects to maximise coverage in unknown/unsurveyed areas Existing video data Access and logistical constraints. Underwater Video Video transects were surveyed with a towed video system designed and built by FRB to collect information about the seabed substrata and dominant biota (Figure 2). The FRB towed video system was designed to run transects across variable seabed habitats and depths. The towed camera frame was constructed of aluminium tube with a stabilising tailfin. A live view Kongsberg-Simrad camera angled at 30 was connected to the vessel by an umbilical cable to a DVD recorder and viewed live on an LCD screen allowing the operator to monitor and adjust the height of the video frame with an electric winch. A second high definition Canon digital camcorder was positioned facing forward at a 45 angle. The system was towed at an average speed of knots and at approximately 1 2 m above the seabed. The position of the towed video frame was recorded every two seconds (approximately every m) with a Differential GPS mounted on the vessel. A Tracklink ultra-short base line (USBL) system compensated for the towed video frame offset from the vessel. The corrected video position (latitude and longitude), date, time, vessel speed and bearing were overlayed on the video footage. These data were also saved to a log file with a software program developed by FRB. All video footage was subsequently dubbed to DVD or captured to external hard drives for analysis. Single-beam Sounder A single-beam sounder was used by FRB to collect bathymetry data at the same time as the underwater video. The sounder data were recorded in an x,y,z log file with the GPS positional data, and overlayed on the video feed. Stereo Video Fish were sampled at the rhodolith beds using remotely deployed stereo video systems (SeaGIS Pty. Ltd., Australia). Stereo systems consisted of a frame with two Canon HV20 cameras with wide angle lenses in housings angled inward at 8 degrees, on bars 75 cm apart and 40 cm above the sea floor, and a diode arm for synchronisation of cameras. Videos were unbaited to prevent attraction of fish from nearby positions that would not occur in normal circumstances. Data Analysis Video Classification The underwater video was classified with the marine habitat classification scheme presented in Table 1. 3

12 The habitat classification scheme was based on refinements to classification schemes from previous Victorian habitat mapping studies (Ball et al. 2006; Ferns and Hough 2000; Ierodiaconou et al. 2007), and is compatible with the proposed National Intertidal/Subtidal Benthic (NISB) Habitat Classification Scheme (Mount et al. 2007). The Victorian Towed Video Classification Program developed in MS Access by Deakin University (Ierodiaconou et al. 2007) was modified by FRB for this project and was used to classify the video and create a Victorian Marine Video Database. The video positional information and depths were extracted from the field log files and imported to the Victorian Towed Video Classification Program. The video files from the two video cameras were then synchronised by their time stamp so that they could be viewed simultaneously. Habitat classification categories (Table 1) were then applied to each video frame position by a marine scientist experienced at interpreting marine video. Stereo Video Stereo video was assessed using two different methods, maximum number (MaxN) and time in view (TiV) (Smith et al., 2011). MaxN was the greatest number of a given fish species in a single frame and has been used to estimate fish abundance in a variety of studies (Watson et al. 2009a; Becker et al. 2012; Birt et al. 2012; Harvey et al. 2012). TiV provides a measure of how fish are using each habitat and was recorded as the total time in seconds that at least one fish of a given species was in view of the left camera during each video deployment (Smith et al., 2011). TiV provides an alternative to MaxN that provides an estimate of how much time species are spending in each habitat. If a fish was lost from view (i.e. hidden in seagrass) and did not reappear within 30 sec it was deemed to have left the sampling area (Smith et al. 2011). Video footage was captured and converted to AVI format using Pinnacle Studio Plus v.11 software (Pinnacle Systems Inc.). Video length was standardised for 55 minutes beginning at the time the cameras settled on the bottom. The computer software packages EVENTMEASURE and PHOTOMEASURE were used to get species abundance and diversity data and estimate fish lengths (SeaGIS Pty. Ltd., Australia). Orientation and location within the camera field of view prevented accurate measurement of some fish, therefore only lengths of fish that could be measured accurately were recorded. 4

13 Figure 2. Towed video frame with live view camera and high definition camcorder (top left, top right), on-board integrated video-recording equipment (bottom left) and USBL Tracklink mounting pole with hydrophone (bottom right). 5

14 Table 1. Marine video habitat classification scheme. Substratum Description Reef Reef/Sediment Sediment Cover Reef (100%) Reef (<25%) / Sediment (>75%) Reef (25 50%) / Sediment (51 75%) Reef (50%) / Sediment (50%) Reef (51 75%) / Sediment (25 50%) Reef (>75%) / Sediment (<25%) Sediment (100%) Reef structure Boulders Broken Cobble Gutters Rubble Solid Reef texture Low profile reef (<1 m) High profile reef (>1 m) Sediment structure Biogenic structure Flat Ripple (Coarse) Ripple (Fine) Sediment texture Gravel/Pebble Sand Shelly sand Silt Macroalgae Sessile invertebrates Macroalgae/ Invertebrate cover Acrocarpia spp. Caulerpa spp. Cystophora spp. Durvillaea potatorum Ecklonia radiata Hormosira banksii Macrocystis angustifolia Phyllospora comosa Sargassum spp. Mixed brown algae Mixed green algae Mixed red algae Undifferentiated algae Drift algae Turfing algae Rhodoliths Ascidians Feather stars Sabella spallanzanii Sea pen Sponges Undifferentiated sessile invertebrates Urchins Bare (0%) Sparse (1 25%) Medium (26 75%) Dense (76 100%) Seagrass Amphibolis antarctica Halophila australis Posidonia australis Zostera sp. Seagrass cover Bare (0%) Sparse (1 25%) Medium (26 75%) Dense (76 100%) 6

15 Results and Discussion Underwater Video The video transects for this project were collected in two stages. Video transects at the western and eastern entrances were surveyed between October 2009 and March 2011 as part of the Statewide LiDAR ground-truthing program (Blake et al. 2012). Additional video transects across Western Port were surveyed between December 2011 and March 2012 to ground truth the LiDAR and multibeam data. The additional video surveys included the rhodolith bed near the eastern entrance. Video surveys covering the rest of the Victorian coastline are presented in Blake et al. (2012). Western Port was categorised into five geographic segments by Marsden et al. (1979) predominantly based upon physical characteristics (Figure 3). These segments have often been referred to in subsequent Western Port studies (e.g. Melbourne Water 2011) and were also adopted to group and describe the video transect locations for the current study. The distribution of video transects in Western Port is shown in Figure 3. Location maps for each video transect are presented in Appendix 1. The combined video data for all Western Port consisted of 88 video transects with a total length of 41 km and 37,187 video data points. The video points in each geographic segment are summarised in Table 2. Appendix 2 presents a summary of observations from all video transects and includes still images extracted from the video. Location maps for the video stills are presented in Appendix 3. The video transect summaries in Appendix 2 are grouped by geographic segments running clockwise from the Western Entrance (Figure 3). It should be noted that the transect codes are not distributed sequentially around Western Port. Figure 3. Western Port segments and video transect survey locations. 7

16 Table 2. Number of video points in each geographic segment. Segment Total video % of all video points points Corinella Segment Lower North Arm Segment 5, Rhyll Segment 14, Upper North Arm Segment 3, Western Entrance Segment 13, Total 37, Substrate and Biota Distribution All video observation data were classified by substrate type and major biota groups to produce the distribution maps presented in Figure 4 to Figure 12. Substrate The substrate types presented in Table 1 were grouped in Figure 4 as follows: Sediment 100% Patchy reef/sediment (all mixed reef and sediment classes) Reef 100%. The overall substrate types from all video transects in Western Port consisted of: 81% sediment 17.5% patchy reef/sediment 1.5% reef. Sediment Sediment was the dominant substrate type observed in Western Port and the sediment texture for all sediment records (including patchy reef/ sediment classes) consisted of: 55% sand 24% shelly sand 19% silt 2% gravel/pebble. The distribution of the dominant sediment texture classes is presented in Figure 5. Sand and shelly sand were the dominant sediment texture classes in the Western Entrance Segment, Lower North Arm and the west side of the Upper North Arm. Shelly sand was often present in the troughs of sand waves and was most commonly seen in areas of high currents such as the deeper channels. Silt was the dominant sediment in the central and east Upper North Arm, Corinella Segment and Rhyll Segment (Figure 5). These areas typically experience lower tidal flows allowing finer sediments to settle. Reef The texture of the reef records (including patchy reef/sediment classes) was 95% low profile with 5% high profile. The high profile reef was primarily broken while the low profile reef was a mixture of broken and rubble. Low profile reef was observed throughout Western Port except for the Corinella Segment (Figure 6). High Profile reef was primarily observed around Eagle Rock and the entrances to the Tooradin and Gentle Annie channels in the Upper North Arm. Limited high profile reef was also observed at Flynn Reef in the Western Entrance segment and near the eastern entrance and within the Rhyll segment (Figure 6). It should be noted that it was difficult to differentiate rock reef from biogenic reef during this survey. Many of the observations defined as reef (Figure 6) were potentially biogenic in origin, being the result of an accumulation of colonies of invertebrates such as bryozoans over a long period of time. Biota Biota (seagrass, macroalgae and/or sessile invertebrates) were present on 73% of the video records. The proportion of biota groups for all video points was as follows: 53% macroalgae 37% seagrass 31% sessile invertebrates. Note that the above figures include video records where more than one biota type was observed. 8

17 Macroalgae Mixed brown algae was present in 33% of the macroalgae records and was generally associated with areas of reef at the western and eastern entrances, as well as areas of rocky reef at Eagle Rock, Crawfish Rock and Corinella (Figure 7). Ecklonia radiata was observed at Crawfish Rock and the eastern entrance. The distribution of Cystophora spp. was restricted to the Cat Bay- Flynn Reef region on the western shore of Phillip Island. Species of Caulerpa were present in 37% of the macroalgae records with the most extensive beds occurring in the Rhyll Segment (Figure 8). Other mixed green algae were present in 3% of the macroalgae records and were observed in the Western Entrance Segment, Lower North Arm and west side of the Upper North Arm (Figure 8). Mixed red algae was the most commonly observed algae class (present in 82% of macroalgae records) and was distributed throughout all the segments (Figure 9). Seagrass The video observations of Zosteraceae were predominantly Zostera nigricaulis, although Zostera muelleri may have also been present in the shallower depths where a transect extended into the intertidal zone at high tide. Zostera sp. was present in 5,880 video points representing 16% of all video records and 43% of seagrass records. Zostera sp. was distributed throughout Western Port (Figure 10). While it was predominantly observed in homogenous beds, it was also commonly observed growing in mixed beds with Amphibolis antarctica and Halophila australis. The overall depth range for observations of Zostera spp. was m, however it was mostly at depths <5 m (88%) and it was only observed at depths >7.7 m in the Western Entrance Segment (Table 3). Halophila australis was present in 42% of seagrass records and was often associated with Zostera spp. and A. antarctica. It was present in all segments and was most abundant in the soft sediments of the Rhyll Segment (Figure 10). Depths ranged from m with most of the observations at depths <5 m (86%). Amphibolis antarctica was present in 45% of the seagrass records. Its distribution was restricted to the higher energy environments of the Western Entrance Segment and around the eastern entrance in the Rhyll Segment (Figure 10). The high percentage occurrence of this species in the seagrass records was due to the longer transects run in the Western Entrance Segment. Depths ranged from m with most of the observations at depths >5 m (62%). Table 3. Total number and depth ranges for video observations of Zostera spp. Segment Total video Minimum Maximum Mean depth points depth (m) depth (m) (m) Corinella Lower North Arm Rhyll 3, Upper North Arm Western Entrance 1, Invertebrates Bryozoans were present in 16% of the sessile invertebrate records at depths of m. Their distribution was restricted to regions around the boundary of the Lower and Upper North Arm Segments and within the Rhyll segment (Figure 11). Bryozoans within the Lower North Arm were associated with areas such as Eagle Rock and Crawfish Rock which have steep sides and experience strong tidal currents. In contrast, they were also observed in the Rhyll Segment as outcrops growing on flat silt in areas of relatively low currents (Figure 11). Ascidians were present in 33% of the sessile invertebrate records at depths of m. They were most commonly observed around the boundary of the Lower and Upper North Arm Segments and were also present in the Western Entrance and Rhyll Segments (Figure 11). In the Lower and Upper North Arms they were most commonly associated with areas of reef and 9

18 shelly sediment, while they were associated with silt in the Rhyll Segment (Figure 11). Sponges were the most frequently observed invertebrate class and were present in 81% of the sessile invertebrate records at depths of m. They were distributed throughout Western Port except for the Corinella Segment (Figure 12), although the absence of observations here may be due to the lower number of transects in this segment. Sponges were associated with areas of reef and shelly sediment. In deeper high current areas such as the centre of channels where the substrate was often shelly sand and rubble, the sponges were stalked in appearance. Sea pens were present in 15% of the sessile invertebrate records at depths of m. They were present on shelly sand in the Lower North and Upper North Arm Segments and on silt in the Rhyll Segment (Figure 12). The densest sea pens were observed at the entrance to Gentle Annie Creek Channel and offshore from Rhyll. Rhodoliths Rhodoliths were observed distributed over an area of approximately 0.5 km 2 at the region near the eastern entrance (Figure 12) described by Harvey and Bird (2008). Depths ranged from m. The rhodoliths were commonly observed amongst seagrass (57% of records). Figure 4. Distribution of substrate types. 10

19 Figure 5. Distribution of sediment types. Figure 6. Distribution of high and low profile reef (including patchy reef/sediment records). 11

20 Figure 7. Distribution of mixed brown algae, E. radiata and Cystophora spp. Figure 8. Distribution of mixed green algae and Caulerpa spp. 12

21 Figure 9. Distribution of mixed red algae. Figure 10. Distribution of seagrass species. 13

22 Figure 11. Distribution of bryozoans and ascidians. Figure 12. Distribution of sponges, sea pens and rhodoliths. 14

23 Stereo Video at Rhodolith Site Stereo video systems were deployed at six sites in the Western Port rhodolith bed on May 2012 at depths between 2 and 5 m. At each site two replicate deployments were undertaken (n = 6 sites x 2 replicates = 12). Videos were deployed for approximately 1 hour. Visibility was generally good within the rhodolith bed allowing fish to be identified up to 2.5 m from cameras. Few fish were observed during the sampling period. Smooth toadfish Tetractenos glaber were observed at all sites but recorded low MaxN and TiV values (Table 4) with 2 being the highest MaxN recorded and 299 seconds the highest TiV. The only other species observed were globefish Diodon nicthemerus and goatfish Upeneichthys vlamingii that were recorded only at site 6 and in low numbers and persistence times (Table 4). Average toadfish lengths ranged between 119 and 131 mm, while the globefish length was 183 mm and average goatfish length 177 mm (Table 4). Table 4. Mean fish TiV, MaxN and length for all species observed at all sites in rhodolith beds with stereo video. Species Site Mean Mean Mean Total Time in view Maximum number (TiV) (MaxN) Length n Smooth toadfish na Globefish Goatfish

24 Acknowledgments The work presented in this report was funded through the Department of Sustainability and Environment (DSE) with Natural Resources Investment Priorities (NRIP) funding. This project was a component of a larger overarching DSE project titled: Building Victoria s statewide tools to support healthy and productive marine environments: scoping statewide marine policy and continuing to build the information that will support it. The overarching project aims to lay the key groundwork to scope future marine environmental policy needs and options to address ongoing threats and challenges to marine biodiversity in Victoria. 16

25 References Ball, D., Blake, S. and Plummer, A. (2006). Review of Marine Habitat Classification Systems. Parks Victoria Technical Series No. 26. Parks Victoria, Melbourne. Becker, A., Coppinger, C., and Whitfield, A.K. (2012). Influence of tides on assemblages and behaviour of fishes associated with shallow seagrass edges and bare sand. Marine Ecology Progress Series 456, Birt, M.J., Harvey, E.S., and Langlois, T.J. (2012). Within and between day variability in temperate reef fish assemblages: Learned response to baited video. Journal of Experimental Marine Biology and Ecology , Blake, S., Ball, D. and Coots, A. (2012). Marine Video Survey of Victoria. Fisheries Victoria Technical Report Series No. 155, Department of Primary Industries, Queenscliff. Blake, S., Young, P., Ball, D. and Coots, A. (2010a). Corangamite Nearshore Marine Habitat Mapping and Assessment. Fisheries Victoria Technical Report Series No. 86, Department of Primary Industries, Queenscliff. Blake, S., Young, P., Ball, D. and Coots, A. (2010b). East Gippsland Nearshore Marine Habitat Mapping and Assessment. Fisheries Victoria Technical Report Series No. 87, Department of Primary Industries, Queenscliff. Ferns, L. W. and Hough, D. (Eds) (2000). Environmental Inventory of Victoria's Marine Ecosystems Stage 3 (2nd edition) - Understanding Biodiversity Representativeness of Victoria's Rocky Reefs. Parks, Flora and Fauna Division, Department of Natural Resources and Environment, East Melbourne. Harvey A.S. and Bird F.L. (2008). Community structure of a rhodolith bed from cold-temperate waters (southern Australia). Australian Journal of Botany 56, Harvey, E.S., Newman, S.J., McLean, D.L., Cappo, M., Meeuwig, J.J., and Skepper, C.L. (2012). Comparison of the relative efficiencies of stereo-bruvs and traps for sampling tropical continental shelf demersal fishes. Fisheries Research , Ierodiaconou, D., Burq, S., Laurenson, L., and Reston, M. (2007). Marine habitat mapping using multibeam data, georeferenced video and image classification techniques: A case study in southwest Victoria. Journal of Spatial Sciences 52, IMCRA Technical Group (1998). Interim Marine and Coastal Regionalisation for Australia: An Ecosystem-based Classification for Marine and Coastal Environments. Version 3.3. IMCRA Technical Group. Environment Australia, Canberra. Marsden M.A.H., Mallett C.W. and Donaldson A.K. (1979). Geological and Physical Setting, Sediments and Environments, Western Port, Victoria. Marine Geology 30, Melbourne Water (2011). Understanding the Western Port Environment. A summary of current knowledge and priorities for future research. Melbourne Water Corporation, East Melbourne. Mount, R., Bricher, P., and Newton, J. (2007). National Intertidal/Subtidal Benthic (NISB) Habitat Classification Scheme Version 1.0. Spatial Science Group, School of Geography and Environmental Studies, University of Tasmania, Hobart. Smith, T.M., Hindell, J.S., Jenkins, G.P., Connolly, R.M., and Keough, M.J. (2011). Edge effects in patchy seagrass landscapes: The role of predation in determining fish distribution. Journal of Experimental Marine Biology and Ecology 399, Watson, D.L., Anderson, M.J., Kendrick, G.A., Nardi, K., and Harvey, E.S. (2009). Effects of protection from fishing on the lengths of targeted and non-targeted fish species at the Houtman Abrolhos Islands, Western Australia. Marine Ecology Progress Series 384, Worley Parsons, Deakin University and EcoNomics (2010). LiDAR-derived marine habitat mapping of the Victorian coast. Final Report to Department of Sustainability and Environment. Worley Parsons Infrastructure and Environment, Melbourne. 17

26 Appendix 1. Video Transect Locations 18

27 Figure 13. Video transect locations Western Entrance Segment. Figure 14. Video transect locations Lower North Arm Segment. 19

28 Figure 15. Video transect locations, Upper North Arm and Corinella (north) Segments. Figure 16. Video transect locations, Rhyll and Corinella (south) Segments. 20

29 Appendix 2. Video Observations 21

30 Western Entrance Segment Video transects in the Western Port Western Entrance segment classified by dominant substrate and biota are presented in Figure 4 to Figure 12. Video still images representing examples of habitats and biota observed in the Western Entrance segment are presented in Figure 17. Locations of the video stills are presented in Appendix 3 (Figure 22). WPT79 Flinders The transect was approximately 1.6 km long and ran over depths of m. The substrate was flat sand dominated by dense A. antarctica to a depth of 8 m (Figure 17-1). Small patches of sparse Zostera sp. (Figure 17-2) and drift algae (Figure 17-3) were also present. Beyond 8 m the substrate was a mixture of sand with fine ripples and low profile rubble reef. Amphibolis antarctica was the dominant biota with mixed brown algae present amongst the reef. Areas of Scaberia agardhii were also present around the edges of the seagrass and rubble reef. WPT116 Shoreham The transect was approximately 1.3 km long and ran over depths of m. Inshore the substrate was patchy low profile reef to a depth of 7 m dominated by a mixture of A. antarctica, mixed brown and red algae and sparse sponges (Figure 17-4). The substrate offshore was sand with a dense cover of A. antarctica and mixed red and brown algae (Figure 17-5). Sparse Zostera sp. replaced the A. antarctica for the final 200 m of the transect from a depth of 7 m (Figure 17-6). WPT50 Shoreham offshore The transect was approximately 1.8 km long and ran over depths of m. The substrate was bare sand with fine ripples. A small area of A. antarctica was present inshore at a depth of 11 m and two small areas of Zostera sp. were present from m (Figure 17-7). WPT117 Somers offshore The transect was approximately 2.6 km long and ran over depths of m. The substrate was sand with patches of shelly sand (Figure 17-8) and was dominated by dense A. antarctica with mixed red and brown algae (Figure 17-9). Patches where the A. antarctica was less dense were colonised by sparse Zostera sp., H. australis (Figure 17-10), sponges and ascidians. WPT74 Somers The transect was approximately 4.7 km long and ran over depths of m. The substrate was sand with fine ripples and occasional patches of mud reef (Figure 17-11). Amphibolis antarctica beds dominated to a depth of 7.9 m. Patches of Zostera sp. and H. australis were also present (Figure 17-12) with the H. australis often dense in places (Figure 17-13). WPT118 Middle Bank The transect was approximately 1.1 km long and ran over depths of m. The substrate was primarily bare sand with coarse ripples containing shelly material in the troughs. Gravel and pebbles were also observed in one of the larger troughs (Figure 17-14). Patches of bare low profile broken and rubble reef were present towards the southern end of the transect from a depth of 13 m (Figure 17-15). A dense aggregation of ascidians and sponges was present from a depth of 16 m (Figure 17-16). WPT119 Ventnor The transect was approximately 0.5 km long and ran over depths of m. The substrate was sand and was dominated by dense A. antarctica mixed with red and brown algae (Figure 17-17). Low profile broken reef dominated by mixed red and brown algae were present offshore from 3 6 m. A small amount of coarse shelly sand and gravel colonised by H. australis was present at the offshore end of the transect to a depth of 7.3 m (Figure 17-18). WPT78 Flynn Reef The transect was approximately 0.3 km long and ran over depths of m. The substrate was a mixture of patchy high profile and low profile broken reef to a depth of 8 m. This was dominated by Cystophora spp., mixed brown algae and mixed red algae (Figure 17-19). Beyond 8 m the substrate was bare sand with coarse ripples. WPT120 Cat Bay The transect was approximately 1.2 km long and ran over depths of m. Inshore the substrate was a combination of low profile broken reef, sand and rubble to a depth of 4 m. Reef was dominated by species of Cystophora, other mixed brown algae and red algae. Sand and rubble were dominated by A. antarctica and mixed algae (Figure 17-20). Beyond 4 m the substrate became a mix of low profile solid and broken reef dominated by species of Cystophora and other mixed algae 22

31 (Figure 17-21). A patch of A. antarctica was present offshore at a depth of 6 m. WPT195 Sandy Point south The transect was approximately 0.3 km long and ran over depths of m. The substrate was a mixture of sand with coarse ripples and patches of rubble. Areas of rubble were colonised by sponges and other sessile invertebrates. WPT184 Cowes The transect was approximately 0.4 km long and ran over depths of m. The substrate was rubble reef and shelly sand colonised by sessile invertebrates, including stalked sponges, bryozoans and gorgonians. WPT180 Tortoise Head west 1 The transect was approximately 0.3 km long and ran over depths of m. The substrate along the deeper western end was flat sand with a high number of infauna burrows and sparse drift seagrass material (Figure 17-22). Halophila australis and Zostera sp. began to dominate the sand as the transect ascended the slope (Figure 17-23). H. australis was first observed at a depth of 6.5 m and Zostera sp. at 3.4 m. The seagrass had a heavy epiphytic algal load in places (Figure 17-24). WPT181 Tortoise Head west 2 The transect was approximately 0.3 km long and ran over depths of m. The substrate along the deeper western end was bare silt with a high number of infauna burrows (Figure 17-25). Two distinct patches of H. australis (Figure 17-26) and Zostera sp. with epiphytic algae were present along the transect with the deepest being recorded at a depth of 4.4 m. WPT182 Tortoise Head south 2 The transect was approximately 0.4 km long and ran over depths of m. The substrate along the deeper eastern end was bare sand with fine ripples and infauna burrows (Figure 17-27). Occasional patches of mixed red algae were present (Figure 17-28). Halophila australis was present at depths < 4 m and dense Zostera sp. at depths < 3.2 m (Figure 17-29). WPT183 Tortoise Head south 1 The transect was approximately 0.2 km long and ran over depths of m. The substrate along the deeper southern end was bare shelly sand with fine ripples, becoming sandy towards the northern end. Halophila australis was present at depths < 3.5 m and Zostera sp. at depths < 2.7 m. Mixed red algae was also present (Figure 17-30). WPT192 Tortoise Head south 3 The transect was approximately 0.3 km long and ran over depths of m. The substrate was sand. At the deeper southern end the sand was bare with infauna burrows. A mixture of dense A. antarctica (Figure 17-31), Zostera sp. and H. australis dominated the sand at depths < 4 m. WPT193 Cowes east 1 The transect was approximately 0.3 km long and ran over depths of m. The substrate was flat shelly sand and rubble colonised by sparse to medium stalked sponges (Figure 17-32). WPT194 Cowes east 2 The transect was approximately 0.1 km long and ran over depths of m. The substrate was bare sand with a mixture of fine ripples and coarse sand waves present. 23

32 1. Dense A. antarctica on sand (WPT79.1). 5. A. antarctica and mixed algae on sand (WPT116.1). 2. Sparse Zostera sp. on sand (WPT79.2). 6. Sparse Zostera sp. on sand (WPT116.4). 3. Dense A. antarctica and patches of drift algae on sand (WPT79.4). 7. Sparse Zostera sp. on sand (WPT50.1). 4. Mixed brown and red algae on low profile broken reef (WPT116.3). 8. Bare shelly sand (WPT117.2). Figure 17. Underwater video still images Western Entrance segment (Images 1 8). 24

33 9. Dense A. antarctica and mixed algae on sand (WPT117.1). 13. Dense H. australis beds on sand (WPT74.1). 10. H. australis on sand (WPT117.3). 14. Gravel and pebbles accumulating in the trough of a sand wave (WPT118.1). 11. Patches of low profile mud reef (WPT74.7). 15. Bare low profile broken and rubble reef (WPT118.2). 12. Mixed Zostera sp. and H. australis beds on sand (WPT74.3). 16. Dense ascidian beds on rubble reef (WPT118.3). Figure 17. Underwater video still images Western Entrance segment (Images 9 16). 25

34 17. Dense A. antarctica with mixed red and brown algae on sand (WPT119.1). 21. Cystophora spp. and mixed algae on solid low profile reef (WPT120.2). 18. H. australis and mixed red algae on shelly sand (WPT119.2). 22. Bare sand with infauna burrows and drift seagrass material (WPT180.1). 19. Mixed brown and red algae on low profile broken reef (WPT78.2). 23. Dense H. australis on sand (WPT180.2). 20. A. antarctica and mixed algae on sand and rubble (WPT120.1). 24. Zostera sp. and H. australis with epiphytic algae (WPT180.3). Figure 17. Underwater video still images Western Entrance segment (Images 17 24). 26

35 25. Bare silt with infauna burrows (WPT181.1). 29. Dense Zostera sp. on sand (WPT182.3). 26. Dense H. australis with epiphytic algae (WPT181.2). 30. H. australis, Zostera sp. and mixed red algae (WPT183.1). 27. Bare sand with infauna burrows (WPT182.1). 31. Dense A. antarctica beds on sand (WPT192.1). 28. Sparse red algae on sand (WPT182.2). 32. Stalked sponges on shelly sand (WPT193.1). Figure 17. Underwater video still images Western Entrance segment (Images 25 32). 27

36 Lower North Arm Video transects in the Lower North Arm segment classified by dominant substrate and biota are presented in Figure 4 to Figure 12. Video still images representing examples of habitats and biota observed in the Lower North Arm are presented in Figure 18. Locations of the video stills are presented in Appendix 3 (Figure 23). WPT196 Sandy Point north The transect was approximately 0.3 km long and ran over depths of m. The substrate was bare sand with a mixture of fine ripples and coarse sand waves present. WPT179 Tea Tree Point south The transect was approximately 0.4 km long and ran over depths of m. The substrate along the deeper western end was primarily flat sand with occasional patches of fine ripples. It was colonised by sparse sponges and ascidians with a high level of drift seagrass also present (Figure 18-1). Ascending the slope Caulerpa sp., H. australis and Zostera sp. began to dominate the sand (Figure 18-2, 3). H. australis was first observed at a depth of 3.2 m and Zostera sp. at 2.9 m. WPT199 Stony Point The transect was approximately 0.1 km long and ran over depths of m. The substrate was shelly sand with patchy low profile rubble and broken reef to a depth of 10 m. Sparse mixed red algae and sponges were present amongst the broken (Figure 18-4) and rubble (Figure 18-5) reef. At depths > 10 m the substrate was bare sand with fine ripples. WPT197 Tea Tree Point north The transect was approximately 0.2 km long and ran over depths of m. The transect traversed a shallow ridge thorough its centre. To the east and west of the ridge the depth dropped to 10 m and the substrate was shelly sand colonised by mixed red and green algae (Figure 18-6) with occasional sponges. The substrate along the ridge was sand colonised by dense Zostera sp. and H. australis from a depth of 7 m. WPT198 Stony Point east The transect was approximately 0.3 km long and ran over depths of m. The substrate was bare sand with a mixture of fine ripples and coarse sand waves present. WPT200 Stony Point north The transect was approximately 50 m long and ran over depths of m. The transect was sand with fine ripples colonised by sparse ascidians and drift seagrass (Figure 18-7). WPT201 Crib Point south The transect was approximately 0.2 km long and ran over depths of m. The substrate was flat sand with sparse drift material, primarily Zostera sp., to a depth of 6 m (Figure 18-8). Dense Zostera sp. (Figure 18-9) and sparse H. australis colonised the substrate in depths < 6 m. WPT203 Middle Spit south The transect was approximately 50 m long and ran over depths of m. The substrate was bare sand with a mixture of fine ripples and coarse sand waves present. WPT205 Hastings south The transect was approximately 0.2 km long and ran over depths of m. The substrate was primarily bare sand with a mixture of fine ripples and coarse sand waves present. Shell material was present in the troughs of the sand waves (Figure 18-10). Sparse sponges were also sometimes present in the troughs. WPT206 Hastings north The transect was approximately 0.3 km long and ran over depths of m. The substrate was a mixture of shelly sand and low profile rubble reef colonised by sponges, ascidians and bryozoans. WPT178 Tyabb The transect was approximately 0.3 km long and ran over depths of m. The substrate along the deeper eastern end of the transect was flat shelly sand colonised by sparse mixed red algae, Caulerpa sp. and sessile invertebrates. Sparse H. australis and dense beds of sea pens were also present (Figure 18-11). Dense Zostera sp. was the dominant biota in depths < 4.5 m (Figure 18-12). WPT207 Middle Spit west 2 The transect was approximately 0.5 km long and ran over depths of m. The substrate was sand with a mixture of fine ripples and coarse sand waves present. The sand was primarily bare but mixed red algae, ascidians and sponges were present in places (Figure 18-13). WPT177 Middle Spit west 1 The transect was approximately 0.3 km long and ran over depths of m. The substrate along the deeper western end of the transect was bare shelly sand with fine ripples (Figure 18-14). Dense Zostera sp. with mixed red algae became 28

37 the dominant biota in depths < 2 m (Figure 18-15). Areas of sparse H. australis were also present (Figure 18-16). WPT172 Middle Spit north The transect was approximately 0.2 km long and ran over depths of m. The substrate in the deeper water was bare sediment with fine ripples and large sand waves. Sparse mixed red algae, sponges and ascidians were present in places (Figure 18-17). A slope to the east of the transect was colonised by dense sponges and ascidians. On the shallower flats at the top of the slope the invertebrates were less common with mixed red and brown algae becoming the dominant biota (Figure 18-18). WPT210 Eagle Rock south The transect was approximately 0.4 km long and ran over depths of m. The substrate was sand with a mixture of fine ripples, coarse sand waves and patches of rubble. Sponges, ascidians and bryozoans colonised the sand and rubble (Figure 18-19). WPT208 Tyabb north 1 The transect was approximately 0.3 km long and ran over depths of m. The substrate was bare sand with a mixture of fine ripples (Figure 18-20) and coarse sand waves present. WPT209 Tyabb north 2 The transect was approximately 0.2 km long and ran over depths of m. The substrate was flat silt with drift algae and seagrass material present to a depth of 4 m (Figure 18-21). Dense beds of Zostera sp. dominated in depths < 4 m (Figure 18-22). WPT176 Eagle Rock west 1 The transect was approximately 0.2 km long and ran over depths of m. The substrate along the shallower northern end of the transect was characterised by sand with fine ripples colonised by mixed red algae, sponges and ascidians (Figure 18-23). The southern end descended a bank to a depth of 18 m. Dense colonies of sponges were the dominant biota on the slope (Figure 18-24) with sparse sponges also present at the bottom of the slope. WPT175 Eagle Rock west 2 The transect was approximately 0.3 km long and ran over depths of m. The substrate along the deeper eastern end was a mixture of shelly sand and rubble reef colonised by sparse sponges, ascidians and bryozoans (Figure 18-25). Moving up the slope the substrate became dominated by low profile broken reef with a diverse cover of sessile invertebrates including sponges, bryozoans, ascidians and gorgonians (Figure 18-26, 27). The urchin Goniocidaris tubaria was also frequently observed (Figure 18-28). In the shallower water at the top of the slope the substrate became rubbly with fewer sessile invertebrates and a higher percentage cover of mixed red algae. WPT174 Eagle Rock The transect was approximately 0.2 km long and ran over depths of m. The substrate along the deeper southern end was sand with fine ripples and was colonised by sparse sponges and ascidians. As the transect went up the slope the substrate turned to low profile broken reef dominated by sponges, bryozoans and other sessile invertebrates (Figure 18-29). Patchy low profile broken reef was present at the top of the slope and was dominated by sponges and mixed algae (Figure 18-30). Small patches of Zostera sp. and H. australis were also present amongst the reef at depths < 3.5 m (Figure 18-31). WPT173 Eagle Rock north The transect was approximately 0.2 km long and ran over depths of m. The substrate was a combination of low profile broken reef and flat patches of sand. The patchy reef was dominated by sessile invertebrates and mixed red algae (Figure 18-32). More extensive areas of reef were dominated by dense sessile invertebrates including sponges, bryozoans and gorgonians (Figure 18-33). WPT171 Crawfish Rock The transect was approximately 0.4 km long and ran over depths of m. The substrate along the deeper eastern end was characterised by a mixture of shelly sand and rubble colonised by sparse sponges, ascidians and bryozoans. Moving up the slope the substrate became dominated by low profile broken reef with a diverse cover of sessile invertebrates, including sponges, bryozoans, ascidians and gorgonians. At the top of the slope the invertebrates were replaced by E. radiata with mixed red and green algae. WPT211 Eagle Rock east The transect was approximately 0.1 km long and ran over depths of m. The substrate was bare sand with a mixture of fine ripples (Figure 18-34) and coarse sand waves present. 29

38 1. Drift seagrass material on sand (WPT179.1). 5. Mixed algae and sponges on rubble (WPT199.2). 2. Caulerpa sp. on sand (WPT179.2). 6. Sparse mixed red algae on shelly sand with fine ripples (WPT197.1). 3. Halophila australis on sand (WPT179.3). 7. Sparse ascidians and Zostera sp. drift material on sand (WPT200.1). 4. Mixed red algae and sponges on broken low profile reef (WPT199.1). 8. Zostera sp. drift material on sand (WPT201.1). Figure 18. Underwater video still images Lower North Arm (Images 1 8). 30

39 9. Dense Zostera sp. on sand (WPT201.2). 13. Mixed red algae, ascidians and sponges on sand (WPT207.1). 10. Shelly sand deposited in the troughs of the larger sand waves (WPT205.1). 14. Bare shelly sand (WPT177.1). 11. Dense sea pens and Zostera sp. on sand (WPT178.1). 15. Dense Zostera sp. and mixed red algae on sand (WPT177.2). 12. Dense Zostera sp. on sand (WPT178.2). 16. Sparse H. australis on sand (WPT177.3). Figure 18. Underwater video still images Lower North Arm (Images 9 16). 31

40 17. Ascidian and sponge colonies on sand (WPT172.1). 21. Zostera sp. drift material on flat silt (WPT209.1). 18. Mixed red and brown algae with sponges on sand (WPT172.2). 22. Dense Zostera sp. on silt (WPT209.2). 19. Sponges and ascidians on sand with fine ripples (WPT210.2). 23. Mixed red algae, sponges and ascidians on sand (WPT176.1). 20. Bare sand with fine ripples (WPT208.2). 24. Sponge colonies present on sandy slope areas (WPT176.2). Figure 18. Underwater video still images Lower North Arm (Images 17 24). 32

41 25. Ascidians and sponges on rubble reef (WPT175.1). 29. Bryozoans and sponges on low profile broken reef (WPT174.2) 26. Sponges and gorgonians on low profile broken reef (WPT175.3). 30. Mixed algae and sponges on low profile broken reef (WPT174.5). 27. Sponges and gorgonians on low profile broken reef (WPT175.4). 31. Mixed Zostera sp. and H. australis (WPT174.6). 28. Urchin, Goniocidaris tubaria (WPT175.2). 32. Sessile invertebrates and mixed red algae on patchy low profile broken reef (WPT173.2). Figure 18. Underwater video still images Lower North Arm (Images 25 32). 33

42 33. Sponges, bryozoans and gorgonians on low profile broken reef (WPT173.4). 34. Bare sand with fine ripples (WPT211.1). Figure 18. Underwater video still images Lower North Arm (Images 33 34). 34

43 Upper North Arm Video transects in the Western Port Upper North Arm segment classified by dominant substrate and biota are presented in Figure 4 to Figure 12. Video still images representing examples of habitats and biota observed in the Upper North Arm are presented in Figure 19. Locations of the video stills are presented in Appendix 3 (Figure 24). WPT170 Warneet Channel entrance The transect was approximately 0.3 km long and ran over depths of m. The substrate was flat shelly sand. Sparse sponges, ascidians, sea pens and Caulerpa sp. were present along the shallower western end of the transect. Halophila australis was also present to a depth of 4.3 m. The deeper eastern end was colonised by sparse sponges and ascidians (Figure 19-1). WPT169 Gentle Annie Channel entrance The transect was approximately 0.2 km long and ran over depths of m. The substrate was primarily sand and shelly sand with patchy colonies of ascidians and sponges present (Figure 19-2). A shallow ridge was present towards the centre of the transect with depths decreasing rapidly from 5 m to 0.6 m. A reef wall was present along the western side of the ridge. The crest of the ridge was colonised by mixed red, green and brown algae and sponges. Areas of low profile bare rubble reef were present in deeper water to the east of the ridge (Figure 19-3) as were areas of dense sea pens (Figure 19-4). WPT168 Tooradin Channel west The transect was approximately 0.2 km long and ran over depths of m. The deeper southern end of the transect was characterised by flat shelly sand with sparse sponges, ascidians and drift algae. The shallower northern end was less shelly with fine ripples. As the transect became shallower sea pens, Caulerpa sp. and sparse Zostera sp. became the dominant biota (Figure 19-5). Zostera sp. was present in depths < 2.8 m. WPT167 Tooradin Channel entrance The transect was approximately 0.4 km long and ran over depths of m. In the deep channels the substrate was flat shelly sand colonised by sparse sponges, ascidians and drift algae (Figure 19-6). The slopes were also sand and colonised by medium to dense invertebrate communities. Isolated reef ledges colonised by sponges were present at the top of two of the slopes (Figure 19-7). WPT212 Joes Island west The transect was approximately 0.1 km long and ran over depths of m. The transect traversed a shallow ridge thorough its centre. To the west of the ridge the depths dropped to 15 m and the substrate was shelly sand colonised by ascidians and sponges (Figure 19-8). The substrate was bare sand with fine ripples along the ridge and to the east of it. WPT164 Joes Island east 1 The transect was approximately 0.2 km long and ran over depths of m. The substrate was bare shelly sand with both coarse and fine ripples present. WPT164b Joes Island east 2 The transect was approximately 0.4 km long and ran over depths of m. The substrate was a mixture of sand, shelly sand and patchy rubble. The sand was generally bare whilst the shelly sand was colonised by sparse sponges, ascidians and drift seagrass material (Figure 19-9). Areas of rubble reef were colonised by sponges and ascidians (Figure 19-10). WPT165 Joes Island The transect was approximately 0.4 km long and ran over depths of m. The substrate was flat shelly sand (Figure 19-11). The east end was colonised by sea pens, mixed red algae and Caulerpa sp. (Figure 19-12). A single patch of Zostera sp. was recorded at a depth of 3.7 m (Figure 19-13). In the deeper channel south of the island sea pens became less common and mixed red algae, drift seagrass material and sparse sponges became the dominant biota. WPT166 French Island National Park west The transect was approximately 0.3 km long and ran over depths of m. The deeper northern half of the transect was bare sand with fine and coarse ripples. A shallow ridge close to the start was colonised by invertebrates. The substrate became more silty towards the shallow southern end of the transect. At depths < 3.3 m Zostera sp. became the dominant biota (Figure 19-14) with H. australis and Caulerpa sp. also present (Figure 19-15). 35

44 WPT215 Joes Island east 3 The transect was approximately 0.1 km long and ran over depths of m. The substrate was bare sand with fine ripples. WPT216 Lyalls Channel entrance The transect was approximately 0.2 km long and ran over depths of m. The substrate was shelly sand and patches of rubble colonised by sparse mixed red algae and sponges (Figure 19-16). WPT163 French Island National Park east The transect was approximately 0.3 km long and ran over depths of m. The substrate along the deeper northern half was flat silt with sparse Caulerpa sp. and sea pens present (Figure 19-17). Sparse Zostera sp. was present at depths < 2.6 m, generally mixed with Caulerpa sp., becoming dense at depths <1.9 m (Figure 19-18). Sparse H. australis was also present. WPT217 Horseshoe Channel The transect was approximately 90 m long and ran over depths of m. The substrate along the deeper northern end was flat silt colonised by sparse Caulerpa sp. Dense Zostera sp. and H. australis dominated the substrate in depths < 2 m. WPT162 Jam Jerrup Point The transect was approximately 0.1 km long and ran over depths of m. The substrate was silt colonised by invertebrates. The water quality was very poor and prevented the identification of the invertebrates. 36

45 1. Ascidian and sponge colonies on shelly sand (WPT170.1). 5. Sea pens and drift algae on shelly sand (WPT168.2). 2. Ascidian and sponge colonies (WPT169.1). 6. Sparse sponges and ascidians on shelly sand (WPT167.1). 3. Low profile bare rubble reef (WPT169.2). 7. Sponges on an isolated low profile rock ledge (WPT167.2). 4. Dense sea pens (WPT169.4). 8. Ascidians and sponges on shelly sand (WPT212.1). Figure 19. Underwater video still images Upper North Arm (Images 1 8). 37

46 9. Sparse ascidians and drift material on shelly sand (WPT164.2). 13. Medium Zostera sp. on sand (WPT165.2). 10. Sessile invertebrates on rubble reef (WPT164.1). 14. Dense Zostera sp. and mixed red algae on silt (WPT166.2). 11. Flat shelly sand (WPT165.3). 15. Sparse H. australis and Zostera sp. on silt (WPT166.1). 12. Sea pens, mixed red algae and Caulerpa sp. on shelly sand (WPT165.1). 16. Sparse mixed red algae and sponges on shelly sand and rubble (WPT216.1). Figure 19. Underwater video still images Upper North Arm (Images 9 16). 38

47 17. Sparse Caulerpa sp. on silt (WPT163.1). 18. Dense Zostera sp. on silt (WPT163.4). Figure 19. Underwater video still images Upper North Arm (Images 17 18). 39

48 Corinella Segment Video transects in the Corinella segment classified by dominant substrate and biota are presented in Figure 4 to Figure 12. Video still images representing examples of habitats and biota observed in the Corinella segment are presented in Figure 20. Locations of the video stills are presented in Appendix 3 (Figure 24 and Figure 25). WPT185 Spit Point south The transect was approximately 0.1 km long and ran over depths of m. The substrate was flat silt. The western half of the transect contained a high level of coarse broken shell material and was colonised by sparse mixed red algae (Figure 20-1). WPT161 Corinella north The transect was approximately 0.1 km long and ran over depths of m. The substrate was flat sand colonised by sparse red algae and sea pens (Figure 20-2) with drift material also present. A shallow bank towards the south of the transect was colonised by dense Zostera sp. from a depth of < 2 m. WPT160 Barge Access Road, French Island The transect was approximately 0.1 km long and ran over depths of m. The substrate was silt. Infauna burrows were visible in the deeper southern section (Figure 20-3). Sparse H. australis and dense Zostera sp. were present in the shallower northern section at depths < 1.8 m (Figure 20-4). 1. Sparse mixed red algae on silt with shells (WPT185.1). 3. Bare silt with infauna burrows (WPT160.1). 2. Sea pens and drift material on flat sand (WPT161.1). 4. Dense Zostera sp. on silt (WPT160.2). Figure 20. Underwater video still images Corinella segment. 40

49 Rhyll Segment Video transects in the Rhyll segment classified by dominant substrate and biota are presented in Figure 4 to Figure 12. Video still images representing examples of habitats and biota observed in the Rhyll segment are presented in Figure 21. Locations of the video stills are presented in Appendix 3 (Figure 25 and Figure 26). WPT156 Stockyard Point west The transect was approximately 0.2 km long and ran over depths of m. The substrate was primarily silt, becoming sandy towards the shallow northern end. Patches of medium and dense H. australis and Zostera sp. were present in depths < 2 m (Figure 21-1). Areas of drift Zostera material were also present (Figure 21-2). WPT158 Pelican Island The transect was approximately 0.3 km long and ran over depths of m. The substrate was a mixture of low profile broken reef and rubble. The broken reef was more common towards the north of the transect with rubble and shell becoming dominant towards the southern end. The reef areas were dominated by diverse sessile invertebrate colonies (Figure 21-3), sponges being the most readily observed. Areas of mixed reef and rubble were also colonised by sessile invertebrates although not as dense (Figure 21-4). Patches of bare rubble and shell were present towards the southern end of the transect (Figure 21-5). WPT186 Coronet Bay 6 The transect was approximately 0.3 km long and ran over depths of m. The substrate was flat silt. Caulerpa sp. and sea pens colonised the sediment to a depth of approximately 4.7 m (Figure 21-6) beyond which only sparse sea pens were present. WPT155 Elizabeth Island east The transect was approximately 0.2 km long and ran over depths of m. The substrate was flat shelly sand with patches of rubble. Sparse erect sponges were present throughout (Figure 21-7). WPT154 Elizabeth Island west The transect was approximately 0.1 km long and ran over depths of m. The substrate was flat shelly sand with sparse erect sponges. Occasional patches of bare shelly sand with fine ripples were also present (Figure 21-8). WPT188 East of Long Point The transect was approximately 0.2 km long and ran over depths of m. The substrate was flat sandy sediment with patchy H. australis and Caulerpa sp. present at depths of around 4 m (Figure 21-9). WPT153 Long Point The transect was approximately 0.2 km long and ran over depths of m. The substrate was primarily bare silt, becoming sandy towards the shallow northern end. Zostera sp. and H. australis were present in depths < 2.3 m (Figure 21-10). WPT152 East Arm The transect was approximately 0.4 km long and ran over depths of m. The substrate was primarily bare shelly sand with fine ripples and occasional areas of silt. Sparse stalked sponges and mixed red algae were present. Small isolated patches of low profile reef were colonised by bryozoans and sponges. WPT187 Coronet Bay 7 The transect was approximately 0.2 km long and ran over depths of m. The substrate was bare silt. WPT147 Coronet Bay 2 The transect was approximately 0.3 km long and ran over depths of m. The substrate was flat silt. The transect was primarily bare but sparse Caulerpa sp, H. australis, sponges and ascidians (Figure 21-11) were present along two small patches. WPT146 Coronet Bay 1 The transect was approximately 0.2 km long and ran over depths of m. The substrate was flat silt. The start and ends were bare, with sparse Caulerpa sp, H. australis, sponges and ascidians colonising the central section (Figure 21-12). WPT148 Coronet Bay 3 The transect was approximately 0.4 km long and ran over depths of m. The substrate was flat silt. The start and ends were bare, with sparse Caulerpa sp, and H. australis colonising the central section (Figure 21-13). WPT149 Coronet Bay 4 The transect was approximately 0.4 km long and ran over depths of m. The substrate was a mixture of bare silt and patchy low profile broken and rubble reef. Areas of reef were colonised by invertebrates including sponges, bryozoans and ascidians (Figure 21-14, 15). 41

50 WPT150 Coronet Bay 5 The transect was approximately 0.4 km long and ran over depths of m. The substrate was primarily bare silt with infauna burrows and occasional sea pens and stalked sponges present. Patches of low and high profile broken and solid reef were present towards the northern third of the transect and were colonised by dense bryozoans and sparse sponges (Figure 21-16, 17). WPT189 Coronet Bay 8 The transect was approximately 0.3 km long and ran over depths of m. The substrate along the eastern three quarters was bare flat silt to a depth of 9 m. The final western quarter was patchy low profile broken reef dominated by sessile invertebrates, in particular bryozoans (Figure 21-18). WPT190 West of Loelia Shoal 1 The transect was approximately 0.4 km long and ran over depths of m. The substrate along the eastern two thirds of the transect was bare flat silt to a depth of 5.5 m. The western third was patchy low profile broken reef dominated by sessile invertebrates, in particular bryozoans (Figure 21-19). WPT191 West of Loelia Shoal 2 The transect was approximately 0.2 km long and ran over depths of m. The substrate was flat silt. Sparse patchy Caulerpa sp. colonised the sediment from the west of the transect to a depth of 4.3 m (Figure 21-20). At depths greater than this the substrate was bare. WPT151 Churchill Island north The transect was approximately 0.3 km long and ran over depths of m. The substrate was flat silt. The deeper eastern end was primarily bare but with occasional sparse patches of Zostera sp at a depth of 2.8 m. The shallower western end was colonised by a mix of H. australis, Zostera sp. and Caulerpa sp. (Figure 21-21). WPT121 Loelia Shoal The transect was approximately 1.0 km long and ran over depths of m. The substrate was soft silt dominated by dense beds of a species of Caulerpa. Sparse H. australis, mixed red algae and sponges were also present throughout the transect (Figure 21-22). Zostera sp. was observed infrequently. WPT122 South of Loelia Shoal The transect was approximately 1.0 km long and ran over depths of m. The substrate was soft silt dominated by dense beds of a species of Caulerpa (Figure 21-23). Sparse H. australis and Zostera sp. were also present throughout the transect (Figure 21-24). WPT82 San Remo The Narrows The transect was approximately 1.2 km long and ran over depths of m. The substrate along the southwest end of the transect was low profile reef dominated by mixed brown algae, mixed red algae and Caulerpa spp.. A dense rhodolith bed became the dominant biota at depths of m (Figure 21-25). To the northeast of the transect H. australis became increasingly common mixed amongst the rhodoliths (Figure 21-26). Dense beds of Zostera sp. were the dominant biota towards the northwest end of the transect from a depth of 3.6 m. WPT123 Homestead Point The transect was approximately 1.3 km long and ran over depths of m. The substrate along the west side of the transect was sandy and dominated by dense A. antarctica and mixed red algae (Figure 21-27). In the central channel the sand became increasingly shelly and the seagrass was replaced by sparse red algae (Figure 21-28). The eastern bank of the channel contained gravel and pebbles with mixed algae (Figure 21-29) and sparse A. antarctica. WPT218 The transect was approximately 0.7 km long and ran over depths of m. The substrate was a mix of sand and low profile broken reef. The reef was dominated by mixed brown algae, Caulerpa sp. and red algae (Figure 21-30). Sponges were present throughout the transect and dominated some areas at its centre (Figure 21-31). Rhodoliths and A. antarctica were also present at places along the transect. WPT219 The transect was approximately 0.3 km long and ran over depths of m. The substrate was primarily shelly sand. Dense rhodoliths mixed with red algae (Figure 21-32) dominated the transect with small patches of Zostera sp., A. antarctica and H. australis were also present. Halophila australis became the dominant species at depths greater than 2.4 m towards the northern end of the transect (Figure 21-33). WPT220 The transect was approximately 0.3 km long and ran over depths of m. The substrate was primarily shelly sand. Zostera sp. and H. australis 42

51 mixed with red algae were present throughout the transect and often in dense patches. Rhodoliths were present at the southern end of the transect and often mixed with Zostera sp. and H. australis (Figure 21-34). WPT221 The transect was approximately 0.6 km long and ran over depths of m. The substrate was primarily shelly sand. Rhodoliths were observed along most of the transect and typically amongst mixed beds of H. australis and Zostera sp. with Caulerpa sp. and red algae (Figure 21-35). Dense rhodoliths largely devoid of other vegetation were located towards the centre of the transect (Figure 21-36). WPT222 The transect was approximately 0.5 km long and ran over depths of m. The substrate was primarily shelly sand with broken reef prominent in the middle of the transect. Rhodoliths (Figure 21-37) were observed along most of the transect apart from the central section where broken reef was present colonised with mixed algae including E. radiata, as well as sponges and ascidians. Amphibolis antarctica (Figure 21-38) and H. australis with Zostera sp. were present growing amongst the rhodoliths. WPT223 The transect was approximately 0.6 km long and ran over depths of m. The substrate was a mix of shelly sand and low profile broken reef. The reef was dominated by mixed brown and red algae, Caulerpa sp. and A. antarctica (Figure 21-39). Rhodoliths were present along most of the transect typically with mixed algae (Figure 21-40) and seagrasses. WPT224 The transect was approximately 0.6 km long and ran over depths of m. The substrate was sandy with dense beds of Zostera sp. (Figure 21-41) and H. australis observed along most of the transect. Rhodoliths were present on the southern two-thirds of the transect amongst the seagrass (Figure 21-42). WPT225 The transect was approximately 0.5 km long and ran over depths of m. The substrate was sandy and dominated by dense beds of Zostera sp. and H. australis interspersed with sparser patches. Rhodoliths were observed at the western end of the transect amongst the Zostera sp. and H. australis (Figure 21-43). 43

52 1. Mixed H. australis and Zostera sp. on sand (WPT156.1). 5. Bare rubble and shells (WPT158.3). 2. Bare sand with drift Zostera sp. material (WPT156.2). 6. Caulerpa sp. and sea pens on flat silt (WPT186.1). 3. Sessile invertebrates on low profile broken reef (WPT158.1). 7. Shelly sand and rubble with erect sponges (WPT155.1). 4. Sessile invertebrates on low profile broken and rubble reef (WPT158.5). 8. Bare shelly sand (WPT154.1). Figure 21. Underwater video still images Rhyll segment (Images 1 8). 44

53 9. H. australis and Caulerpa sp. on sand (WPT188.1). 13. Sparse Caulerpa sp. on silt (WPT148.1). 10. Zostera sp. and H. australis on sand (WPT153.1). 14. Bryozoans and sponges on low profile reef (WPT149.1). 11. Sparse Caulerpa sp., H. australis and sponges on silty substrate (WPT147.1). 15. Bryozoans and sponges on low profile reef (WPT149.2). 12. Sparse Caulerpa sp., H. australis and ascidians on silty substrate (WPT146.1). 16. Bryozoan colony on low profile reef (WPT150.1). Figure 21. Underwater video still images Rhyll segment (Images 9 16). 45

54 17. Dense bryozoan colonies on high profile reef (WPT150.2). 21. Zostera sp. with Caulerpa sp. (WPT151.1). 18. Bryozoan colonies on low profile broken reef (WPT189.1). 22. Caulerpa sp, mixed red algae and sponges on silt (WPT121.1). 19. Bryozoan colonies on low profile broken reef (WPT190.2). 23. Dense Caulerpa sp. on silt (WPT122.1). 20. Sparse Caulerpa sp. on silty (WPT191.1). 24. Caulerpa sp. and Zostera sp. on silt (WPT122.2). Figure 21. Underwater video still images Rhyll segment (Images 17 24). 46

55 25. Dense rhodolith bed (WPT82.3). 29. Gravel and pebbles with mixed red and brown algae (WPT123.3). 26. Dense rhodolith bed with H. australis (WPT82.5). 30. Low profile reef with mixed algae (WPT218.5). 27. Dense A. antarctica and mixed red algae on sand (WPT123.1). 31. Sponges (WPT218.2). 28. Shelly sand and sparse red algae (WPT123.2). 32. Rhodoliths (WPT219.1). Figure 21. Underwater video still images Rhyll segment (Images 25 32). 47

56 33. Halophila australis and rhodoliths (WPT 219.3). 37. Rhodoliths (WPT 222.4). 34. Rhodoliths with Zostera sp. and H. australis (WPT 220.2). 38. Amphibolis antarctica and rhodoliths (WP_T222.3). 35. Halophila australis, Caulerpa sp. and rhodoliths (WPT 221.2). 39. Low profile reef with mixed algae (WP_T223.4). 36. Rhodoliths (WPT 221.7). 40. Rhodoliths and mixed algae (WP_T223.5). Figure 21. Underwater video still images Rhyll segment (Images 33 40). 48

57 41. Dense Zostera sp. (WP_T224.2). 43 Rhodoliths, Zostera sp., H. australis (WPT 225.5). 42. Rhodoliths, Zostera sp. and H. australis (WP_T224.8). Figure 21. Underwater video still images Rhyll segment (Images 41 43). 49

58 Appendix 3. Video Still Image Locations 50

59 Figure 22. Video still locations Western Entrance Segment. Figure 23. Video still locations Lower North Arm Segment. 51

60 Figure 24. Video still locations Upper North Arm and Corinella (north) Segments. Figure 25. Video still locations Rhyll and Corinella (south) Segments (see also Figure 26). 52

61 Figure 26. Video still locations at rhodolith area north of San Remo within Rhyll segment. 53