Victorian Subtidal Reef Monitoring Program - Parks Victoria

Parks Victoria is responsible for managing the Victorian protectedarea network, which ranges from wilderness areas to metropolitanparks and includes both marine and terrestrial components.Our role is to protect the natural and cultural values of the parksand other assets we manage, while providing a great range ofoutdoor opportunities for all Victorians and visitors.A broad range of environmental research and monitoring activitiessupported by Parks Victoria provides information to enhance parkmanagement decisions. This Technical Series highlights some ofthe environmental research and monitoring activities done withinVictoria’s protected area network.Healthy Parks Healthy PeopleFor more information contact the Parks Victoria Information Centreon 13 1963, or visit www.parkweb.vic.gov.auparks victoria technical series • Number 28 Victorian Subtidal Reef Monitoring Program – The Reef Biota in the Port Phillip Bay Marine Sanctuariesp 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 sNumber 28Victorian Subtidal Reef Monitoring ProgramThe Reef Biota in the Port Phillip Bay Marine SanctuariesAuthors: Malcolm Lindsay and Matt EdmundsFebruary 2006

© Parks VictoriaAll rights reserved. This document is subject to the Copyright Act 1968, no part of thispublication may be reproduced, stored in a retrieval system, or transmitted in any form, or byany means, electronic, mechanical, photocopying or otherwise without the prior permission ofthe publisher.First published 2006Published by Parks VictoriaLevel 10, 535 Bourke Street, Melbourne Victoria 3000Opinions expressed by the Authors of this publication are not necessarily those of ParksVictoria, unless expressly stated. Parks Victoria and all persons involved in the preparation anddistribution of this publication do not accept any responsibility for the accuracy of any of theopinions or information contained in the publication.Authors:Malcolm LindsayMatt EdmundsNational Library of AustraliaCataloguing-in-publication dataIncludes bibliography.ISSN 1448-4935CitationLindsay, M. and Edmunds, M. (2006). Victorian Subtidal Reef Monitoring Program: The ReefBiota in the Port Phillip Bay Marine Sanctuaries. Parks Victoria Technical Series No. 28.Parks Victoria, Melbourne.Printed on environmentally friendly paper

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringEXECUTIVE SUMMARYShallow reef habitats cover extensive areas along the Victorian coast and are dominated byseaweeds, mobile invertebrates and fishes. These reefs are known for their high biologicalcomplexity, species diversity and productivity. They also have significant economic valuethrough commercial and recreational fishing, diving and other tourism activities. To effectivelymanage and conserve these important and biologically rich habitats, the VictorianGovernment has established a long-term Subtidal Reef Monitoring Program (SRMP). Overtime the SRMP will provide information on the status of Victorian reef flora and fauna anddetermine the nature and magnitude of trends in species populations and species diversitythrough time.The subtidal reef monitoring program is established throughout Victoria for all relevantmarine protected areas. This study involved the third (2005) survey of the Northern PortPhillip Bay sites associated with the Point Cooke, Jawbone and Ricketts Point MarineSanctuaries.The subtidal reef monitoring program uses standardised underwater visual census methodsto survey algae, macroinvertebrates and fish. For northern Port Phillip Bay, the sites are inshallow water between 2 and 4 m deep. This report aims to:• Provide general descriptions of the biological communities and species populations ateach monitoring site in April 2005;• Identify any unusual biological phenomena such as interesting or unique communities orspecies; and• Identify any introduced species at the monitoring locations.The surveys were done along a 200 m transect line. Each transect was surveyed for:1. Abundance and size structure of large fishes;2. Abundance of cryptic fishes and benthic invertebrates;3. Percentage cover of macroalgae; and4. Density of dominant kelp species.The macroalgae at the northern Port Phillip Bay sites was generally sparse compared to thecoastal regions, reflecting the sheltered bay to estuarine environmental conditions. Most ofthe coverage was by a mixture of carpeting green Caulerpa species, including Caulerpaflexilis, C. brownii, C. geminata, C. longifolia and C. remotifolia. Caulerpa was most abundantat the Point Cooke and Ricketts Point regions, along with a sparse mixture of small brownand red algal species. Other predominant species were encrusting coralline algae, commonkelp Ecklonia radiata and sea lettuce Ulva sp. The algae at Jawbone Marine Sanctuaryconsisted predominantly of filamentous brown algae, characteristic of estuarineenvironments with freshwater and nutrient inputs nearby. Some temporal changes wereapparent between surveys, however the relative similarities and differences between sitesremained the same between the three surveys.The invertebrate fauna at all sites was dominated by the common sea urchin Heliocidariserthrogramma, blacklip abalone Haliotis rubra and seastars. The seastars Patiriella calcar, P.brevispina, Tosia australis, Uniophora granifera and Coscinasterias muricata were prevalentin the Point Cooke and Jawbone regions. The most abundant seastars in the Ricketts Pointregion was Tosia australis, Petricia vernicina and Coscinasterias muricata. Some minorchanges in species abundances were observed between surveys, however the generalassemblage structure of each site remained the same.I

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringThe fish fauna was generally sparse in northern Port Phillip Bay, having low species richnessand low abundances of most species. The fauna at all locations was dominated by thesouthern hulafish Trachinops caudimaculatus, with abundances of this species varyingsubstantially between sites and times. This made it difficult to detect any patterns in thestructure of fish assemblages in each of the marine sanctuary regions with such a short timeseries.Results from the three monitoring surveys describe the reef community structure for a briefsnapshot in time. Reef communities are dynamic over short, medium and long time scales.As monitoring continues and longer-term datasets are accumulated (over multiple years todecades) the program will be able to more adequately reflect trends and changes incommunity or population structure as well as to identify specific ecological patterns occurringin these ecosystems.II

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringCONTENTSEXECUTIVE SUMMARY............................................................................................. ICONTENTS............................................................................................................... IIIINDEX OF FIGURES AND TABLES.......................................................................... V1. INTRODUCTION ................................................................................................... 11.1 Subtidal Reef Ecosystems Of Northern Port Phillip Bay ...................................................11.2 Subtidal Reef Monitoring Program ....................................................................................41.2.1 Objectives....................................................................................................................................41.2.2 Monitoring Protocols and Locations ............................................................................................61.2.3 Monitoring in Port Phillip Bay Marine Sanctuaries .......................................................................62. METHODS............................................................................................................. 72.1 Site Selection and Survey Times ......................................................................................72.2 Census Method .................................................................................................................82.2.1 Transect Layout...........................................................................................................................82.2.2 Method 1 – Mobile Fishes and Cephalopods..............................................................................92.2.3 Method 2 – Invertebrates and Cryptic Fishes .............................................................................92.2.4 Method 3 – Macroalgae and Sessile Invertebrates.....................................................................92.2.5 Method 4 – Macrocystis ...........................................................................................................102.3 Data Analysis ..................................................................................................................112.3.1 Community Structure.................................................................................................................112.3.2 Depiction of Community Differences.........................................................................................112.3.3 Trends in Community Structure.................................................................................................122.3.4 Species Diversity.......................................................................................................................122.3.5 Species Populations..................................................................................................................123. REGIONAL ANALYSIS....................................................................................... 143.1 Biogeography ...................................................................................................................143.2 Macroalgae......................................................................................................................143.3 Invertebrates ....................................................................................................................173.4 Fishes...............................................................................................................................194. POINT COOKE MARINE SANCTUARY............................................................. 214.1 Monitoring Sites................................................................................................................214.2 Macroalgae......................................................................................................................214.4 Invertebrates ...................................................................................................................234.5 Fishes..............................................................................................................................265. JAWBONE MARINE SANCTUARY.................................................................... 285. JAWBONE MARINE SANCTUARY.................................................................... 285.1 Monitoring Sites...............................................................................................................28III

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring5.2 Macroalgae.......................................................................................................................285.3 Invertebrates ...................................................................................................................305.4 Fishes..............................................................................................................................336. RICKETTS POINT MARINE SANCTUARY ........................................................ 356.1 Monitoring Sites...............................................................................................................356.2 Macroalgae.......................................................................................................................356.3 Invertebrates ...................................................................................................................376.4 Fishes..............................................................................................................................397. REFERENCES .................................................................................................... 418. ACKNOWLEDGEMENTS ................................................................................... 42IV

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringINDEX OF FIGURES AND TABLESFIGURESFigure 1.1. Examples of species of invertebrates found on subtidal reefs in northern PortPhillip Bay........................................................................................................................ 3Figure 1.2. Examples of macroalgae found on subtidal reefs in northern Port Phillip Bay...... 4Figure 1.3. Examples of fish species found on subtidal reefs in northern Port Phillip Bay...... 4Figure 1.4 An example plot depicting change in an environmental, population or communityvariable over time (days, months or years). The black circles denote examples ofmonitoring times. ............................................................................................................. 5Figure 2.1. Location of monitoring sites in northern Port Phillip Bay. Marine Sanctuaries areindicated in yellow. .......................................................................................................... 7Figure 2.2. Biologist-diver with transect reel. ....................................................................... 13Figure 2.3. The cover of macrophytes is measured by the number of points intersecting eachspecies on the quadrat grid. .......................................................................................... 13Figure 3.1. MDS plot of algal assemblage structure in northern Port Phillip Bay. Sites arelabelled next to the point representing the first survey at each site. Stress = 0.09. ...... 15Figure 3.2. Trends in algal species richness. ........................................................................ 16Figure 3.3. Trends in algal species diversity. ........................................................................ 16Figure 3.4. MDS plot of invertebrate assemblage structure in northern Port Phillip Bay. Sitesare labelled next to the point representing the first survey at each site. Stress = 0.09. 17Figure 3.5. Trends in invertebrate species richness.............................................................. 18Figure 3.6. Trends in invertebrate species diversity.............................................................. 18Figure 3.7. MDS plot of fishes assemblage structure in northern Port Phillip Bay. Sites arelabelled next to the point representing the first survey at each site. Stress = 0.09. ...... 19Figure 3.8. Trends in fish species richness. .......................................................................... 20Figure 3.9. Trends in fish species diversity. .......................................................................... 20Figure 4.1. Abundances of selected macroalgal species in the Point Cooke region............. 22Figure 4.2. Abundances of selected invertebrates in the vicinity of Point Cooke MarineSanctuary. .....................................................................................................................24Figure 4.3. Abundances of selected invertebrate species in the vicinity of Point Cooke MarineSanctuary. .....................................................................................................................25Figure 4.4. Mean sizes (± 95% confidence intervals) of black lip abalone Haliotis rubra atPoint Cooke Marine Sanctuary and RAAF Base reference site. ................................... 26Figure 4.5. Abundances of southern hulafish Trachinops caudimaculatus and little rockwhiting Neoodax balteatus in the vicinity of Point Cooke Marine Sanctuary. ................ 27Figure 5.1. Abundances of selected macroalgal species in the vicinity of Jawbone MarineSanctuary. .....................................................................................................................29V

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringFigure 5.2 Abundances of selected invertebrate species in the vicinity of Jawbone MarineSanctuary. .....................................................................................................................31Figure 5.3 Abundances of selected invertebrate species in the vicinity of Jawbone MarineSanctuary. .....................................................................................................................32Figure 5.4. Mean sizes (± 95% confidence intervals) of black lip abalone Haliotis rubra atJawbone Marine Sanctuary and Point Gellibrand reference site................................... 33Figure 5.5. Abundances of southern hulafish Trachinops caudimaculatus and little rockwhiting Neoodax balteatus in the vicinity of Point Cooke Marine Sanctuary. ................ 34Figure 6.1. Abundances of selected macroalgal species in the vicinity of Ricketts PointMarine Sanctuary. ......................................................................................................... 36Figure 6.2 Abundances of selected invertebrate species in the vicinity of Ricketts PointMarine Sanctuary. ......................................................................................................... 38Figure 6.3. Mean sizes (± 95% confidence intervals) of black lip abalone Haliotis rubra atRicketts Point Marine Sanctuary and Halfmoon Bay reference site.............................. 39Figure 6.4. Abundances of southern hulafish Trachinops caudimaculatus and little rockwhiting Neoodax balteatus in the vicinity of Ricketts Point Marine Sanctuary............... 40VI

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringTABLESTable 2.1. Subtidal reef monitoring sites in northern Port Phillip Bay ..................................... 8Table 2.2. Mobile fish surveyed in northern Port Phillip Bay using Method 1. ....................... 9Table 2.3 Invertebrates and cryptic fish surveyed in northern Port Phillip Bay using Method 2....................................................................................................................................... 10Table 2.4 Macroalgae surveyed in northern Port Phillip Bay using Method 3....................... 10VII

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring1. INTRODUCTION1.1 Subtidal Reef Ecosystems Of Northern Port Phillip BayRocky reefs in Port Phillip Bay are generally restricted to the near-shore regions ofheadlands and points. Reefs in the northwest of the bay, along the Geelong Arm, arepredominantly near Point Lilias, Point Wilson and Kirks Point. These reefs occur in shortcoastal strips from the intertidal zone to 2-4 m depth, bounded by bare sediment andseagrass habitats a short distance form shore (10s of metres). Occasional small patches ofreef, 10-50 m across, are present further offshore, particularly between Point Wilson andKirks Point. These patch reefs are mostly 1-3 m deep.Along the northern shore of the bay, small patches of shallow reef, interspersed by siltysands, are also present in the vicinity of Point Cooke, western beach (north of Point Cooke),Altona, Jawbone (Williamstown Rifle Range), Point Gellibrand and Point Ormond. Thesereefs are generally no deeper than 4 m. More extensive reef habitat is present fromSandringham to Ricketts Point, extending from the shore 50-100 m and to a depth ofapproximately 6 m.In general the reefs in the northern half of the bay are quite sheltered from the prevailingnorthwesterly to southwesterly weather and are not subject to large waves, strong currents orswell. One exception is Ricketts Point which can be subject to steep, short-period wavesduring southwesterly storms. These reefs are in estuarine conditions and are subject to lowersalinities from coastal runoff, rivers and drains, as well as considerable temperature ranges(as low as 8° C in winter and as high as 23° C in summer). The northern reefs are alsofrequently subject to turbid conditions from phytoplankton blooms and disturbance ofadjacent, moderate to fine sediments.Reefs on the northeastern side of the bay, particularly between Halfmoon Bay and RickettsPoint, are exposed to the prevailing westerly weather across a relatively long fetch of water.Consequently, these reefs are occasionally subject to turbulent wind-driven waves. Thesenortheastern reefs are also influenced, to some extent, by the Yarra River plume and eastcoastdrainages.Reef habitats in the north of Port Phillip Bay are different from the predominant reef habitatsin Victoria, which occur on exposed open coasts. While there are similar species inhabitingboth sheltered reefs in the north of the bay and reefs on more exposed coasts, there aresubstantial and important differences in community structure between the two reefenvironments. Seaweeds are the predominant biological habitat providers in both locationshowever the importance of large canopy forming species such as crayweed Phyllosporacomosa and common kelp Ecklonia radiata is much reduced on reefs in the bay. Smallerspecies of brown algae (10 – 30 cm high) such as Sargassum spp. and Dictyota dichotomaand green algae, particularly in the genus Caulerpa, are often the dominant habitat providerson reefs in the bay (Figure 1.1). Species of Caulerpa can form large, mixed-speciesassemblages creating meadow-like habitat in some locations. Grazed algal turfs and hardencrusting layers of coralline algae are also important species growing directly over the rockysubstratum.Grazing and predatory mobile invertebrates are prominent animal inhabitants of the reef(Figure 1.2). Large grazing species such as the urchin Heliocidaris erythrogramma andblacklip abalone Haliotis rubra can occur in very high densities and are enormouslyproductive components of the bay’s reef communities. These species can significantlyinfluence the growth and survival of habitat forming algal species and so are importantstructuring components of reef communities. Filter feeding species feed on phytoplanktonand detritus and can be important for transferring nutrients and energy from the water1

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoringcolumn to other species directly inhabiting reefs. Filter feeding species on reefs in the northof the bay include aggregations of mussels Mytilus edulis planulatus, ascidians such asHerdmania momus and the introduced European fanworm Sabella spallanzanii. Other filterfeeders are colonial species including sponges, bryozoans and soft corals such asErythropodium hicksoni. Important predatory invertebrates include octopus such as Octopusberrima and seastars including Coscinasterias muricata and Uniophora granifera. Predatorygastropod molluscs (shellfish) include the dogwhelk Dicathais orbita and Pleuroplocaaustralasia.Fish are usually dominant components of reef ecosystems both in terms of biomass andecological function. Reef fish assemblages include predators such as snapper Crysophrysauratus, omnivores including zebrafish Girella zebra, planktivores such as the southernhulafish Trachinops caudimaculatus and picker-feeders such as horseshoe leatherjacketMeuschenia hippocrepis. Schools of small baitfish, particularly herrings, sardines, pilchardsand sprats are common over reef habitats in the north of the bay. Reefs also provideimportant habitat and source of food for juveniles of many fish species including snapperCrysophrys auratus on reefs in the north and east of the bay. Many fish species play asubstantial ecological role in the functioning and structuring of reef ecosystems. Reef fishassemblages in the north of Port Phillip Bay are different to those in exposed coastal whichtend to have higher abundances of wrasses (labrids), cales (odacids) and leatherjackets(monocanthids).Although shallow reef ecosystems in Victoria are dominated, in terms of biomass andproduction, by seaweeds, mobile invertebrates and fishes, there are many other importantbiological components to the reef ecosystem. These include small species of crustaceansand molluscs from 0.1 to 10 mm in size (mesoinvertebrates), occupying various niches asgrazers, predators and detritovores. At the microscopic level, films of microalgae andbacteria on the reef surface are also important.Victoria’s shallow reefs are a very important component of the marine environment becauseof their high biological complexity, species diversity and productivity. Subtidal reef habitatshave important social and cultural values, which incorporate aesthetic, recreational,commercial and historical aspects. Shallow subtidal reefs also have significant economicvalue, through commercial fishing of reef species such as abalone and sea urchins, as wellas recreational fishing, diving and other tourism activities. Reefs in the north of Port PhillipBay are highly accessible components of the marine environment because of their proximityto the large population centres of Melbourne and surrounding suburbs. Consequently, thesereefs are subject to pressures due to human activities.2

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringSea urchin Heliocidaris erythrogrammaBlacklip abalone Haliotis rubraEleven armed seastar Coscinasterias muricataSeastar Uniophora graniferaBiscuit star Tosia australis with filamentousStony coral Plesiastrea versiporagreen and brown algaeFigure 1.1. Examples of species of invertebrates found on subtidal reefs in northern Port Phillip Bay.3

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringGreen algae Caulerpa browniiSpecies of thallose red algae with green algaeCaulerpa brownii, Caulerpa trifaria and Cladophora prolifera.Figure 1.2. Examples of macroalgae found on subtidal reefs in northern Port Phillip BaySouthern hulafish Trachinops caudimaculatusGlobefish Diodon nichthemerusFigure 1.3. Examples of fish species found on subtidal reefs in northern Port Phillip Bay.1.2 Subtidal Reef Monitoring Program1.2.1 ObjectivesAn important aspect of the management and conservation of Victorian marine naturalresources and assets is assessing the condition of the ecosystem and how this changes overtime. Combined with an understanding of ecosystem processes, this information is importantto manage any threats or pressures on the environment to ensure ecosystem sustainability.Consequently, the Victorian Government has established a long-term Subtidal ReefMonitoring Program (SRMP). The primary objective of the SRMP is to provide information onthe status of Victorian reef flora and fauna (focussing on macroalgae, macroinvertebratesand fish). This includes monitoring the nature and magnitude of trends in speciesabundances, species diversity and community structure. This is achieved through regularsurveys at locations throughout Victoria, encompassing both representative and uniquehabitats and communities.Information from the SRMP allows managers to better understand and interpret long-termchanges in the population and community dynamics of Victoria’s reef flora and fauna. As alonger time series of data is collected, the SRMP will allow managers to:4

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring• compare changes in the status of species populations and biological communitiesbetween highly protected marine national parks and marine sanctuaries and otherVictorian reef areas (e.g. Edgar and Barrett 1997, 1999);• determine associations between species and between species and environmentalparameters (e.g. depth, exposure, reef topography) and assess how these associationsvary through space and time (e.g. Edgar et al. 1997; Dayton et al. 1998; Edmunds, Roob& Ferns 2000);• provide benchmarks for assessing the effectiveness of management actions, inaccordance with international best practice for quality environmental managementsystems (Holling 1978; Meredith 1997); and• determine the responses of species and communities to unforeseen and unpredictableevents such as marine pest invasions, mass mortality events, oil spills, severe stormevents and climate change (e.g. Ebeling et al. 1985; Edgar 1998; Roob et al. 2000;Sweatman et al. 2003).A monitoring survey gives an estimate of population abundance and community structure ata small window in time. Patterns seen in data from periodic surveys are unlikely to exactlymatch changes in the real populations over time or definitively predict the size and nature offuture variation. Plots of changes over time are unlikely to match the changes in realpopulations because changes over shorter time periods and actual minima and maxima maynot be adequately sampled (Figure 1.4). Furthermore, because the nature and magnitude ofenvironmental variation is different over different time scales, variation over long periods maynot be adequately predicted from shorter-term data. Sources of environmental variation canoperate at the scale of months (e.g. seasonal variation), years (e.g. el Niño), decades (e.g.extreme storm events) or even centuries (e.g. global warming). Other studies indicate thismonitoring program will begin to adequately reflect average trends and patterns as thesurveys continue over longer periods (multiple years to decades). Results always need to beinterpreted within the context of the time scale over which they have been measureParameterTimeFigure 1.4 An example plot depicting change in an environmental, population or community variableover time (days, months or years). The black circles denote examples of monitoring times. Note howdata from these times may not necessarily reflect patterns over shorter time periods, or true maxima orminima over longer time periods. Note further how data from any window of 2 or 3 consecutivemonitoring times fails to adequately estimate the patterns or variation over the longer time period.5

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring1.2.2 Monitoring Protocols and LocationsThe SRMP uses standardised underwater visual census methods based on an approachdeveloped and applied in Tasmania by Edgar and Barrett (1997). Details of standardoperational procedures and quality control protocols for Victoria’s SRMP are described inEdmunds and Hart (2003).The SRMP was initiated in May 1998 with 15 sites established on subtidal reef habitats in thevicinity of Port Phillip Heads Marine National Park. In 1999 the SRMP was expanded to reefsin the vicinity of the Bunurong Marine National Park, Phillip Island, and Wilsons PromontoryMarine National Park.In 2003 and 2004, the Subtidal Reef Monitoring Program was expanded to include MarineNational Parks and Marine Sanctuaries throughout Victoria.1.2.3 Monitoring in Port Phillip Bay Marine SanctuariesThis report describes the subtidal reef monitoring program and the results of the first twosurveys of reefs in northern Port Phillip Bay, incorporating marine sanctuaries at PointCooke, Jawbone and Ricketts Point. The objectives of this report were to:1. Provide an overview of the methods used for the SRMP;2. Provide general descriptions of the biological communities and species populations ateach monitoring site in April 2004 and to describe changes that have occurred since thefirst monitoring survey in 2003;3. Identify any unusual biological phenomena such as interesting or unique communities orspecies; and4. Identify any introduced species at the monitoring locations.6

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring2. METHODS2.1 Site Selection and Survey TimesSix paired monitoring sites were established on northern Port Phillip Bay subtidal reefs inMarch-April 2003 (Figure 2.1; Table 2.1). One monitoring site was located within, and onesite was located outside, each marine sanctuary. All monitoring sites were located onrepresentative subtidal reef habitat in each location.The second survey of the established monitoring sites on northern Port Phillip Bay reefs wasin April 2004, while the third survey occurred April 2005.Six paired monitoring sites were established on northern Port Phillip Bay subtidal reefs inMarch-April 2003 (Figure 2.1; Table 2.1). One monitoring site was located within, and onesite was located outside, each marine sanctuary. Sanctuary monitoring sites were located onrepresentative subtidal reef habitat within each marine sanctuary, with reference siteslocated on similar habitat nearby. A description of the monitoring sites is given in thefollowing sections for each marine sanctuary. Data from reference monitoring sites will allowanalysis and interpretation of trends or changes in species composition and communitystructure within the marine sanctuaries.5810000Melbourne58050003Williamstown4MGA Northing (m)58000005795000Point CookRAAF Base126Halfmoon BayPort Phillip Bay5Ricketts Point57900005785000300000 305000 310000 315000 320000 325000 330000MGA Easting (m)Figure 2.1. Location of monitoring sites in northern Port Phillip Bay. Marine Sanctuaries are indicatedin yellow.7

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringTable 2.1. Subtidal reef monitoring sites in northern Port Phillip BaySite No. Site Name Sanctuary/Reference Depth (m)Point Cooke Marine Sanctuary4101 Point Cooke Sanctuary 34102 RAAF Base Reference 4Jawbone Marine Sanctuary4103 Jawbone Sanctuary 34104 Point Gellibrand Reference 2Ricketts Point4105 Ricketts Point Sanctuary 34106 Halfmoon Bay Reference 32.2 Census Method2.2.1 Transect LayoutThe visual census methods of Edgar and Barrett (Edgar and Barrett 1997, 1999; Edgar et al.1997) are used for this monitoring program as they are non-destructive and providequantitative data on a large number of species, and the structure of the reef communities.The Edgar-Barrett method is also used in Tasmania, New South Wales and WesternAustralia. The adoption of this method in Victoria provides a systematic and comparableapproach to monitoring reefs in southern Australia. The surveys in Victoria are in accordancewith a standard operational procedure to ensure long-term integrity and quality of the data(Edmunds and Hart 2003).At most monitoring locations in Victoria, surveying along the 5 m depth contour is consideredoptimal because diving times are not limited by decompression schedules and these reefsare of interest to natural resource managers. However, the actual depth that can be surveyedvaries with reef extent, geomorphology and exposure. Monitoring sites along the westerncoast of Victoria are between 3 and 8 m deep.Each site is located using differential GPS and marked with a buoy or the boat anchor. A100 m numbered and weighted transect line is run along the appropriate depth contour eitherside of the central marker. The resulting 200 m of line is divided into four contiguous 50 msections (T1 to T4). The orientation of transect is the same for each survey, with T1 generallytoward the north or east (i.e. anticlockwise along the coast).For each transect, three different census methods were used to obtain adequate descriptiveinformation on reef communities at different spatial scales. These involved the census of: (1)the abundance and size structure of large fishes; (2) the abundance of cryptic fishes andbenthic invertebrates; and (3) the percent cover of macroalgae and sessile invertebrates.Over 100 species were observed during the monitoring program along the western coast ofVictoria (Tables 2.2 - 2.4). The depth, horizontal visibility, sea state and cloud cover arerecorded for each site. Horizontal visibility is gauged by the distance along the transect lineto detect a 100 mm long fish. All field observations are recorded on underwater paper.8

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring2.2.2 Method 1 – Mobile Fishes and CephalopodsThe densities of mobile large fishes and cephalopods are estimated by a diver swimming upone side of a 50 m section of the transect, and then back along the other. The diver recordsthe number and estimated size-class of fish, within 5 m of each side of the line. The sizeclassesfor fish are 25, 50, 75, 100, 125, 150, 200, 250, 300, 350, 375, 400, 500, 625, 750,875 and 1000+ mm. Each diver has size-marks on their underwater slate to enablecalibration of their size estimates. A total of four 10 x 50 m sections of the 200m transect arecensused for mobile fish at each site. The data for easily sexed species are recordedseparately for males and female/juveniles. Such species include the blue-throated wrasseNotolabrus tetricus, herring cale Odax cyanomelas, barber perch Caesioperca rasor, rosywrasse Pseudolabrus psittaculus and some leatherjackets.Table 2.2. Mobile fish surveyed in northern Port Phillip Bay using Method 1.Method 1Trygonorrhina fasciata Pempheris multiradiata Nesogobius sp.Atherinid sp. Girella zebra Acanthaluteres vittigerNeosebastes scorpaenoides Scorpis aequipinnis Meuschenia flavolineataPlatycephalus bassensis Tilodon sexfasciatus Meuschenia freycinetiCaesioperca rasor Enoplosus armatus Meuschenia hippocrepisTrachinops caudimaculatus Parma victoriae Aracana ornataArripis trutta Cheilodactylus nigripes Tetractenos glaberChrysophrys auratus Dactylophora nigricans Diodon nichthemerusUpeneichthys vlaminghii Neoodax balteatus2.2.3 Method 2 – Invertebrates and Cryptic FishesCryptic fishes and megafaunal invertebrates (non-sessile: e.g. large molluscs, echinoderms,crustaceans) are counted along the transect lines used for the fish survey. A diver countsanimals within 1 m of one side of the line (a total of four 1 x 50 m sections of the 200 mtransect). A pole carried by the diver is used to standardise the 1 m distance. The maximumlength of abalone is measured in situ using vernier callipers whenever possible. Selectedspecimens are collected for identification and preservation in a reference collection.2.2.4 Method 3 – Macroalgae and Sessile InvertebratesThe area covered by macroalgal and sessile invertebrate species is quantified by placing a0.25 m 2 quadrat at 10 m intervals along the transect line and determining the percent coverof the all plant species. The quadrat is divided into a grid of 7 x 7 perpendicular wires, giving50 points (including one corner). Cover is estimated by counting the number of times eachspecies occurs directly under the 50 positions on the quadrat (1.25 m 2 for each of the 50 msections of the transect line). Selected specimens are collected for identification andpreservation in a reference collection.9

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring2.2.5 Method 4 – MacrocystisIn addition to macroalgal cover, the density of Macrocystis angustifolia plants is estimated.While swimming along the 200 m transect line, a diver counts all observable plants within5 m either side of the line, for each 10 m section of the transect (giving counts for 100 m 2sections of the transect).Table 2.3 Invertebrates and cryptic fish surveyed in northern Port Phillip Bay using Method 2.Method 2Mollusca Echinodermata PolychaetaPlagusia chabrus Tosia australis Sabella spallanzaniHaliotis rubraTosia magnificaDiodora lineata Petricia vernicina Cryptic FishDicathais orbita Patiriella exigua Aetapcus maculatusPleuroploca australasia Patiriella calcar Vincentia conspersaCeratosoma brevicaudatum Patiriella brevispina Pempheris multiradiataOstrea angasi Coscinasterias muricata Bovichtus angustifronsAsterias amurensisParablennius tasmanianusCrustacea Uniophora granifera Norfolkia clarkeiStrigopagurus strigimanus Amblypneustes sp. Heteroclinus perspicillatusPagurid unidentified Heliocidaris erythrogramma Nesogobius sp.Nectocarcinus tuberculatusBrachaluteres jacksonianusTable 2.4 Macroalgae surveyed in northern Port Phillip Bay using Method 3.Method 3Chlorophyta (green) Phaeophyta (brown) Rhodophyta (red algae)Ulva spp Leathesia difformis Haliptilon roseumCladophora prolifera Splachnidium rugosum Encrusting corallinesCladophora spp Dictyota dichotoma Gigartina sp.Caulerpa remotifolia Dilophus marginatus Callophyllis rangiferinaCaulerpa longifolia Lobospira bicuspidata Plocamium angustumCaulerpa brownii Distromium flabellatum Dictymenia harveyanaCaulerpa flexilis Zonaria turneriana Laurencia filiformisCaulerpa geminata Colpomenia peregrina Laurencia tumidaCaulerpa simpliciusculaEcklonia radiataCodium spp Caulocystis cephalornithos Sessile InvertebratesFilamentous greens Acrocarpia paniculata Other spongesCystophora moniliformis Plesiastrea versiporaCystophora retroflexaAmathia sp.Cystophora subfarcinata Unidentified colonial ascidianSargassum linearifolium Erythropodium hicksoniiSargassum spinuligerumSargassum spp10

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring2.3 Data AnalysisTo identify changes and trends within marine protected areas, sites from inside each MPAwill be compared to paired reference sites outside each MPA. For the first survey, data fromall sites is compared together. This allows an assessment of biota at each site to be placedin a bioregional context. Descriptions of the biota and community structure at each site arealso provided.2.3.1 Community StructureCommunity structure is a function of both the species present and the abundance of eachspecies. The community structure between pairs of samples was compared using the Bray-Curtis dissimilarity coefficient. This index compares the abundance of each species betweentwo samples to give a single value of the difference between the samples, expressed as apercentage (Faith et al. 1987; Clarke 1993).Prior to analysis, the data were log transformed to weight down the influence of highlyabundant species in describing community structure, giving a more even weighting betweenabundant and rarer species (following abundance transformations by Sweatman et al. 2000).The Bray-Curtis dissimilarity index was calculated for all possible combinations of sites. Thisresulted in a matrix of pair-wise comparisons known as a dissimilarity matrix. Thedissimilarity matrix is also termed a distance matrix as it effectively represents distancesbetween samples in hyper-dimensional space. The dissimilarity matrix was used for allanalyses of community structure in this study.2.3.2 Depiction of Community DifferencesThe hyper-dimensional information in the dissimilarity matrix was simplified and depictedusing non-metric multidimensional scaling (MDS; Clarke 1993). This ordination method findsthe representation in fewer dimensions that best depicts the actual patterns in the hyperdimensionaldata (i.e. reduces the number of dimensions while depicting the salientrelationships between the samples). The MDS results were then depicted graphically to showdifferences between the replicates at each location. The distance between points on the MDSplot is representative of the relative difference in community structure.Kruskall stress is an indicator statistic calculated during the ordination process and indicatesthe degree of disparity between the reduced dimensional data set and the original hyperdimensionaldata set. A guide to interpreting the Kruskall stress indicator is given by Clarke(1993): (< 0.1) a good ordination with no real risk of drawing false inferences; (< 0.2) canlead to a usable picture, although for values at the upper end of this range there is potentialto mislead; and (> 0.2) likely to yield plots which can be dangerous to interpret. Theseguidelines are simplistic and increasing stress is correlated with increasing numbers ofsamples. Where high stress was encountered with a two-dimensional data set, threedimensionalsolutions were sought to ensure an adequate representation of the higherdimensionalpatterns.11

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring2.3.3 Trends in Community StructureTrends in community structure will be examined quantitatively when further surveys havebeen completed at each location.2.3.4 Species DiversitySpecies diversity involves the consideration of two components: species richness andevenness. Species richness is the number of species present in the community whileevenness is the degree of similarity of abundances between species. If all species in acommunity have similar abundances, then the community has a high degree of evenness. Ifa community has most of the individuals belonging to one species, it has low evenness.Species diversity is a combination of species richness and the relative abundance of eachspecies, and is often referred to as species heterogeneity. Measures of diversity give anindication of the likelihood that two individuals selected at random from a community aredifferent species.Species richness (S) was enumerated by the total species count per site. This value wasused for calculation of evenness and heterogeneity statistics. Species diversity (i.e.heterogeneity among species) was described using the reciprocal of Simpson’s index(1/D Simpson = Hill’s N 2 ). This value describes species diversity as a combination of speciesrichness (i.e. the number of species) and species evenness (i.e. the equitability of theabundances of the species). The value varies between 1 and s (i.e. the total number ofspecies in the sample) with higher values indicating higher diversity. In general, Hills N 2gives an indication of the number of dominant species within a community. Hills N 2 providesmore weighting for common species, in contrast to indices such as the Shannon-WeinerIndex (Krebs 1999), which weights the rarer species. The weighting of common species wasconsidered more appropriate for this study because the sampling regime is designed totarget the more common species.2.3.5 Species PopulationsThe abundance of each species was summarised by calculating total counts of fish andinvertebrates and total percentage cover of macroalgae, for each site. Specific analyses oftrends in species abundances over time will be examined when additional monitoring surveyshave been completed. Except for small species (e.g. Trachinops caudimaculatus), fishabundances were generally low at sites in northern Port Phillip Bay. This meant theassessment of population size structures of fishes was not appropriate for this region. Thepopulation size structure for blacklip abalone Haliotis rubra was assessed by calculatingmean lengths and size frequency curves.12

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringFigure 2.2. Biologist-diver with transect reel.Figure 2.3. The cover of macrophytes is measured by the number of points intersecting each specieson the quadrat grid.13

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring3. REGIONAL ANALYSIS3.1 BiogeographyVictoria’s marine environment has been classified into five bioregions. These bioregionsreflect differences in physical processes such as ocean currents and geology, which in turninfluence the distribution of ecosystems and diversity over scales of 100-1000 km. PointCooke, Jawbone and Ricketts Point Marine Sanctuaries are in the Victorian Embaymentsbioregion, which includes Port Phillip Bay, Westernport Bay and Corner Inlet.The reef habitats in the northern half of the bay are quite sheltered from the prevailingnorthwesterly to southwesterly weather and are not subject to large waves, strong currents orswell. However, these reefs are in estuarine conditions and are subject to lower salinitiesfrom coastal runoff, rivers and drains (35-31 PSU), as well as considerable temperatureranges (as low as 8° C in winter and as high as 23° C in summer). The northern reefs arealso frequently subject to turbid conditions, from phytoplankton blooms, coastal dischargesand disturbance of nearby fine sediments.Reefs on the northeastern side of the bay, particularly between Halfmoon Bay and RickettsPoint, are exposed to the prevailing westerly weather across a relatively long fetch of water.Consequently, these reefs are occasionally subject to turbulent wind-driven waves. Thesenortheastern reefs are also influenced, to some extent, by the Yarra River plume and eastcoastdrainages.These environmental differences are reflected in the floral and faunal assemblages, with thesubtidal reef biota of northern Port Phillip Bay being quite different to those of the coastalCentral Victoria bioregion reefs (Edmunds et al. 2003a and 2003b). Analyses of the ParksVictoria monitoring data for the indicated the principal differences between these bioregionswere:• A lack of kelps and other large seaweeds on the northern reefs, having a higherpredominance of smaller algae such as Caulerpa species, Dictyota dichotoma and Ulvasp;• Higher abundances in the north of the sea urchin Heliocidaris erythrogramma, seastarsPatiriella brevispina, P. calcar and Coscinasteria muricata and the featherworm Sabellaspallanzanii – the Heads region having higher abundances of the crinoid Cenoliatrichoptera, warrener (periwinkle) Turbo undulatus, greenlip abalone Haliotis laevigataand seastars of the Nectria genus; and• Higher abundances of hulafish Trachinops caudimaculatus, moonlighter Tilodonsexfasciatus and salmon Arripis sp in the north with a predominance of labrids (wrasses),Odax spp (cales) and monacanthids (leatherjackets) in the Heads region (Edmunds et al.2003a and 2003b).3.2 MacroalgaeWithin the north of the bay, the two most northern sites Jawbone and Point Gellibrand werethe most different from the northwestern (Point Cooke) and northeastern (Ricketts Point)regions of the Bay (Figure 3.1). This was largely because of the absence of the carpetinggreen Caulerpa algae and a predominance of filamentous brown turfs at the northern sites.Temporal changes in assemblage structure appeared to be greater in the Point Cooke andJawbone region, especially at Point Gellibrand (Site 4). This was largely because the totalabundances of algae are low in these sites so minor abundance changes have a relatively14

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoringgreater effect on the overall community structure. In general, the relative differences betweenareas in northern Port Phillip Bay were maintained between 2003 and 2005 (Figure 3.1).The species richness and diversity of algal assemblages in the Ricketts Point region wasgenerally higher than elsewhere in Port Phillip Bay, with Point Cooke and Jawbone siteshaving the lowest species richness and slightly lower diversity (Figures 3.2 and 3.3).S1S2S6S4S5S3Figure 3.1. MDS plot of algal assemblage structure in northern Port Phillip Bay. Sites are labelled nextto the point representing the first survey at each site. Stress = 0.09.15

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringPoint Cooke MS Jawbone MS Ricketts Point MS303030Site 1 Site 3 Site 5SanctuarySitesSpecies Count201020102010000303030Site 2 Site 4 Site 6ReferenceSitesSpecies Count20102010201002003 2004 2005 2006Year02003 2004 2005 2006Year02003 2004 2005 2006YearFigure 3.2. Trends in algal species richness.Point Cooke MS Jawbone MS Ricketts Point MS151515Site 1 Site 3 Site 5101010SanctuarySitesHills N2555000151515Site 2 Site 4 Site 6ReferenceSitesHills N210101055502003 2004 2005 2006Year02003 2004 2005 2006Year02003 2004 2005 2006YearFigure 3.3. Trends in algal species diversity.16

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring3.3 InvertebratesWithin the north of the bay, the invertebrate assemblages were different between thenorthwest (Point Cooke), northern (Jawbone) and northeastern (Ricketts Point) regions of theBay (Figure 3.4). The main differences between these regions were largely because ofvariations in the abundance of blacklip abalone Haliotis rubra, common sea urchinHeliocidaris erythrogramma and seastars Patiriella calcar and P. brevispina.Although slight differences in invertebrate assemblage structure was apparent betweenyears, the relative differences between regions and sites was maintained (Figure 3.4).The species richness of the invertebrate assemblages were similar between sites andregions in northern Port Phillip Bay, although a higher species richness was observed atPoint Cooke during the first survey (Figure 3.5). The diversity at most sites was relatively lowbecause of a dominance of only two species: Heliocidaris erythrogramma and Haliotis rubra(Figure 3.6). The invertebrate species diversity was slightly higher at Point Cooke andJawbone.S1S2S4S3S6S5Figure 3.4. MDS plot of invertebrate assemblage structure in northern Port Phillip Bay. Sites arelabelled next to the point representing the first survey at each site. Stress = 0.09.17

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringPoint Cooke MS Jawbone MS Ricketts Point MS303030Site 1 Site 3 Site 5SanctuarySitesSpecies Count201020102010000303030Site 2 Site 4 Site 6ReferenceSitesSpecies Count20102010201002003 2004 2005 2006Year02003 2004 2005 2006Year02003 2004 2005 2006YearFigure 3.5. Trends in invertebrate species richness.Point Cooke MS Jawbone MS Ricketts Point MS1081010Site 1 Site 3 Site 588SanctuarySitesHills N2646464222000ReferenceSitesHills N2108641010Site 2 Site 4 Site 688664422202003 2004 2005 2006Year02003 2004 2005 2006Year02003 2004 2005 2006YearFigure 3.6. Trends in invertebrate species diversity.18

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring3.4 FishesMost species were very low in density, apart from one or two species in high abundancesthat dominated the community structure. The southern hulafish Trachinops caudimaculatuswas the most dominant species, but was highly variable in abundances between times withinsites, making it difficult to make regional comparisons in assemblage structure. The highvariability in the dominant Trachinops cuadimaculatus contributes to the high variation of allsites through time, in particular Point Cooke and Point Gellibrand (Site 1 and 4; Figure 3.7).The species richness was relatively higher at the northeastern Bay sites (Ricketts Pointregion) with the lowest numbers of species at the northern sites (Jawbone region; Figure3.8). The dominance in number of Trachinops caudimaculatus was reflected in the diversitystatistics, with all sites having low fish species diversity (Figure 3.9). However, in the lastsurvey higher species diversity was recorded at both sites in the Point Cooke region, inparticular at the RAAF Base (Site 2).S3S1S5S6S4S2Figure 3.7. MDS plot of fishes assemblage structure in northern Port Phillip Bay. Sites are labellednext to the point representing the first survey at each site. Stress = 0.09.19

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringPoint Cooke MS Jawbone MS Ricketts Point MS303030Site 1 Site 3 Site 5SanctuarySitesSpecies Count201020102010000303030Site 2 Site 4 Site 6ReferenceSitesSpecies Count20102010201002003 2004 2005 2006Year02003 2004 2005 2006Year02003 2004 2005 2006YearFigure 3.8. Trends in fish species richness.Point Cooke MS Jawbone MS Ricketts Point MS1081010Site 1 Site 3 Site 588SanctuarySitesHills N2646464222000ReferenceSitesHills N2108641010Site 2 Site 4 Site 688664422202003 2004 2005 2006Year02003 2004 2005 2006Year02003 2004 2005 2006YearFigure 3.9. Trends in fish species diversity.20

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring4. POINT COOKE MARINE SANCTUARY4.1 Monitoring SitesPoint Cooke Marine Sanctuary is close to Werribee on the northwestern shore of the bay.The subtidal reef at Point Cooke consists of low-relief, textured basalt reef interspersed withpatches of sand and mud. The Point Cooke monitoring site (Site 4101) was positioned alongthe 3-4 m depth contour over the reef and patches of sand.A reference monitoring site was located offshore from the RAAF Base at Laverton (RAAFBase; Site 4102), approximately 3 km southwest of Point Cooke Marine Sanctuary. The reefat RAAF Base is similar to Point Cooke. It consists mostly of low-relief reef but with lessextensive patches of sand and mud. The RAAF Base monitoring site is at 3-4 m depth.4.2 MacroalgaeThe reef at Point Cooke (Site 4101) was patchy and interspersed with large areas of baresediment. This was reflected in the patchy distribution and cover of algae at this site. Thedominant species was common kelp Ecklonia radiata, but this occurred in low abundance.Smaller species in low abundance during the first survey, but much higher in abundanceduring the second survey included the green algae Ulva sp. and Caulerpa remotifolia. Otherspecies present included brown algae Dilophus marginatus and Dictyota dichotoma andthallose red algae such as Gigartina sp.The RAAF Base (Site 4102) was predominantly a Caulerpa bed assemblage dominated byCaulerpa flexilis, but also included C. longifolia, C. brownii, C. remotifolia, and C.simpliciuscula. Ecklonia radiata and patches of encrusting corallines were also present at thissite. In general, there was a higher total cover of algae at RAAF Base than at Point Cooke.Changes in species cover were observed between the three surveys. The green carpetingalga Caulerpa remotifolia increased its cover at Point Cooke, and at RAAF Base (Figure 4.1).There was also an apparent decline in the cover of the common kelp Ecklonia radiata at theRAAF Base and the cover of pink encrusting coralline at both sites (Figure 4.1).21

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring30Point Cooke MSEcklonia radiata30RAAF BasePercent Cover201020100300Encrusting corallines30Percent Cover201020100300Caulerpa remotifolia30Percent Cover201020100030Ulva sp.30Percent Cover2010201002003 2004 2005 2006Year02003 2004 2005 2006YearFigure 4.1. Abundances of selected macroalgal species in the Point Cooke region.22

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring4.4 InvertebratesThe invertebrate assemblages at Point Cooke and RAAF Base were dominated byechinoderms, with similar species at both sites. Heliocidaris erythrogramma was highlyabundant, with generally 320 individuals per 200 m 2 at Point Cooke and 800-1000 per 200m 2 at RAAF Base. The seastars Patiriella brevispina, Coscinasterias muricata, Uniophoragranifera and Tosia australis were abundant at these sites. Tosia australis, Pateriellabrevispina and Coscinasterias muricata were the predominant assemblage components. Theseastar Patiriella calcar was present in moderate abundances at Point Cooke (70-90 per 200m 2 ), but was not observed at the RAAF Base site. The blacklip abalone Haliotis rubra washighly abundant at each site, with 330-380 individuals per 200 m 2 at Point Cooke and 100-210 per 200 m 2 at RAAF Base (Figure 4.2).Between the three surveys, there was a relatively large decrease in the abundance ofblacklip abalone H. rubra, the sea urchin Heliocidaris erythrogramma and the seastar Tosiaaustralis (Figure 4.2). Other species showed little change or high variability between thethree survey periods (Figures 4.2 and 4.3).The mean size of blacklip abalone Haliotis rubra ranged between 84 and 91 mm. There wereno marked differences between sites and times in the vicinity of the Point Cooke MarineSanctuary (Figure 4.4). Smaller individuals were more frequent at RAAF Base during the firstsurvey.23

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring500Point Cooke MSHaliotis rubra500RAAF Base400400Abundance300200300200100100001200Heliocidaris erythrogramma1200Abundance80040080040001100Patiriella brevispina1108888Abundance6644664422220060Tosia australis60Abundance4020402002003 2004 2005 2006Year02003 2004 2005 2006YearFigure 4.2. Abundances of selected invertebrates in the vicinity of Point Cooke Marine Sanctuary.24

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring50Point Cooke MSRAAF BaseCoscinasterias muricata504040Abundance3020302010100500Uniophora granifera504040Abundance302030201010030Petricia vernicina030Abundance2010201002003 2004 2005 2006Year02003 2004 2005 2006YearFigure 4.3. Abundances of selected invertebrate species in the vicinity of Point Cooke MarineSanctuary.25

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring120Pt Cooke120RAAF Base110110Length (mm)100908010090807070602003 2004 2005 2006Time602003 2004 2005 2006TimeFigure 4.4. Mean sizes (± 95% confidence intervals) of black lip abalone Haliotis rubra at Point CookeMarine Sanctuary and RAAF Base reference site.4.5 FishesThe southern hulafish Trachinops caudimaculatus was one of the most abundant fishspecies at Point Cooke and RAAF Base. Other typical species were little rock whitingNeoodax balteatus, southern goatfish Upeinichthys vlaminghii and small unidentified fishes(probably post-larval stages). There were occasional sightings of banjo ray Trygonorrhinafasciata, zebrafish Girella zebra, moonlighter Tilodon sexfasciatus, dusky morwongDactylophora nigricans and globefish Diodon nichthemerus.During the first survey large numbers of the southern hulafish, Trachinops caudimaculatus,were observed at both sites, however in the subsequent surveys few individuals were seen(Figure 4.5). There was a low number of little rock whiting Neoodax balteatus observedduring the first survey and higher numbers seen in subsequent surveys (Figure 4.5).26

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring250Point Cooke MSRAAF BaseTrachinops caudimaculatus250200200Abundance1501001501005050050Neoodax balteatus0504040Abundance30203020101002003 2004 2005 2006Year02003 2004 2005 2006YearFigure 4.5. Abundances of southern hulafish Trachinops caudimaculatus and little rock whitingNeoodax balteatus in the vicinity of Point Cooke Marine Sanctuary.27

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring5. JAWBONE MARINE SANCTUARY5.1 Monitoring SitesJawbone Marine Sanctuary is situated between Altona and Williamstown in the north of thebay. The subtidal reef at Jawbone Marine Sanctuary is in shallow water (< 4 m) and consistsof large basalt boulders sloping steeply to sand at the toe of the reef. The Jawbonemonitoring site (Site 4103) is close to shore and is on the 2-3 m isobath.A reference monitoring site was located approximately 2 km east of Jawbone MarineSanctuary at Point Gellibrand (Site 4104), Williamstown. Reef structure at this site wassimilar to the Jawbone reef, consisting predominantly of large basalt boulders, but wasgenerally flatter with more sand among reef patches. The monitoring site at Point Gellibrandwas at 2 m depth.5.2 MacroalgaeThe algal assemblage at Jawbone Marine Sanctuary (Site 4103) was not very diverse,consisting predominantly of filamentous brown algae (Ectocarpales), 19-42 % and a lowcover of encrusting coralline algae and occasional plants of Ecklonia radiata, Sargassum sppand Dictyota dichotoma. Other distinctive reef covering organisms were the coral Plesiastraversipora and sponges, but these had less than 10 % cover.The Point Gellibrand (Site 4104) was also characterised by a low abundance of algalspecies, the predominant consistent cover being by encrusting coralline algae, with a coverof approximately 10 %, Ulva with 6-14 % cover and Ecklonia radiata with 2 % cover. Otherspecies present included sparse coverings of green algae Caulerpa geminata and Codiumsp, the medium-sized brown algae Cystophora moniliformis, Cystophora retroflexa,Sargassum fallax and Sargassum spinuligerum, filamentous brown algae (Ectocarpales) andsmall red algae such as Laurencia spp.The assemblage structures at Jawbone and Point Gelibrand appear to reflect the strongerestuarine influence in this region. The lower abundances of larger brown algae and higherabundances Ectocarpales spp. are an indicator of high nutrient concentrations and lowersalinities.The sparse, patchy nature of the macroalgae within and near the Jawbone Marine Sanctuarymakes it difficult to intrepret time trends after only three surveys. This will be assessed morethoroughly as future surveys provide a better picture of temporal and spatial variations inabundances. Of note was a reduction in the coverage of filamentous brown algal turfs, anincrease in Ecklonia radiata at both sites as well as a decrease in encrusting coralline algalcover at Point Gellibrand (Figure 5.1).28

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring30Jawbone MSEcklonia radiata30Point GellibrandPercent Cover201020100018Encrusting corallines18Percent Cover1261260050Filamentous browns504040Percent Cover3020103020100024Ulva sp.24Percent Cover16816802003 2004 2005 2006Year02003 2004 2005 2006YearFigure 5.1. Abundances of selected macroalgal species in the vicinity of Jawbone Marine Sanctuary.29

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring5.3 InvertebratesThe mobile invertebrate assemblages at Jawbone and Point Gellibrand were composedlargely of the sea urchin Heliocidaris erythrogramma and the seastars Patiriella brevispina,Patiriella calcar and Coscinasterias muricata. The abundance of H. erythrogramma washigher at Point Gellibrand, 230-330 compared to 100-150 per 200 m 2 at Jawbone.Abundances of blacklip abalone Haliotis rubra were moderate to low at both sites with 10-40per 200 m 2 . The seastars Tosia australis and Uniophora granifera were also common atthese sites (Figure 5.3).Some species, such as Patiriella calcar, Coscinasterias muricata and Uniophora graniferaappear quite variable through time at both sites (Figures 5.2 and 5.3). Other species, suchas Heliocidaris erythrogramma, Patiriella brevispina and Tosia australis appear to follow atrend. There was a decreasing trend in Heliocidaris erythrogramma, particularly clear atJawbone. Similarly there was also a general decreasing trend in Patiriella brevispina at bothsites (Figure 5.2) and Tosia australis at Jawbone (Figure 5.3). Abundance of Tosia australisat Point Gellibrand was very similar throughout the 3 surveys (Figure 5.3). However, furthersurveys are needed to elucidate any major patterns.The size structure of the Haliotis rubra was difficult to determine for Jawbone and PointGellibrand during the first survey because only a small number of individuals were observedand measured. During the second survey, abundances were greater and the average lengthwas 75-83 mm, with more smaller individuals observed at Jawbone. Larger abundances andmean sizes were recorded during the third survey, with mean lengths of 85 mm for JawboneMS and 86 mm for Point Gellibrand (Figure 5.4).30

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring50Jawbone MSHaliotis rubra50Point Gellibrand4040Abundance30203020101000Heliocidaris erythrogramma400400300300Abundance2001002001000090Patiriella brevispina90Abundance6030603000Patiriella calcar120120Abundance8040804002003 2004 2005 2006Year02003 2004 2005 2006YearFigure 5.2 Abundances of selected invertebrate species in the vicinity of Jawbone Marine Sanctuary.31

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring50Jawbone MSPoint GellibrandCoscinasterias muricata504040Abundance3020302010100210Uniophora granifera21Abundance147147021Tosia australis021Abundance14714702003 2004 2005 2006Year02003 2004 2005 2006YearFigure 5.3 Abundances of selected invertebrate species in the vicinity of Jawbone Marine Sanctuary.32

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring120Jawbone120Point Gellibrand110110Length (mm)100908010090807070602003 2004 2005 2006Time602003 2004 2005 2006TimeFigure 5.4. Mean sizes (± 95% confidence intervals) of black lip abalone Haliotis rubra at JawboneMarine Sanctuary and Point Gellibrand reference site.5.4 FishesAt Jawbone and Point Gellibrand, nearly all fish observed were southern hulafish Trachinopscaudimaculatus. Other species, present in very low densities, were zebrafish Girella zebra,dusky morwong Dactylophora nigricans and little rock whiting Neoodax balteatus. During thefirst survey, the density of T. caudimaculatus at Jawbone was exceptionally high, 2200 per200 m 2 , with a major decrease observed in the subsequent surveys (Figure 5.5). Neoodaxbalteatus was first observed during the second survey. During the third survey lowernumbers were observed at both sites (Figure 5.5).33

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring2200Jawbone MSPoint GellibrandTrachinops caudimaculatus220016501650Abundance11005501100550015Neoodax balteatus015Abundance10510502003 2004 2005 2006Year02003 2004 2005 2006YearFigure 5.5. Abundances of southern hulafish Trachinops caudimaculatus and little rock whitingNeoodax balteatus in the vicinity of Point Cooke Marine Sanctuary.34

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring6. RICKETTS POINT MARINE SANCTUARY6.1 Monitoring SitesRicketts Point Marine Sanctuary is near Beaumaris on the north-eastern shore of the bay.The reef at Ricketts Point is low relief sandstone reef with occasional steps and crevices,erosion holes and small rubble fields. The Ricketts Point monitoring site (Site 4105) was at3 m depth, approximately 70 m offshore from the intertidal rock platform.A reference monitoring site (Halfmoon Bay; Site 4106) was located approximately 3 km northof Ricketts Point at Halfmoon Bay. The reef at Halfmoon Bay is low to medium relief (to 1 m)reef with occasional ledges and overhangs, but also having patches of flat, rubbly reef inplaces. This site was at 3 m depth.The reef habitats at Ricketts Point Marine Sanctuary and Halfmoon Bay have less estuarineinfluence than the other northern Port Phillip Bay reefs and are also more exposed to wavesduring prevailing westerly and southwesterly weather.6.2 MacroalgaeRicketts Point (Site 4105) and Halfmoon Bay (Site 4106) were predominantly Caulerpa bedassemblages. At Ricketts Point, Caulerpa geminata was the dominant Caulerpa species,with Ecklonia radiata, Ulva, Cystophora spp, Sargassum spp and encrusting corallines alsobeing common components of the flora. Most of the substratum cover was by C. geminata(25 %), E. radiata (1-10 %) and encrusting corallines (5 %). All other algal species weregenerally less than 5 % in cover. The stony coral Plesiastrea versipora was also apredominant of the substratum cover at Ricketts Point.At Halfmoon Bay, the assemblage was dominated by a mixture of Caulerpa remotifolia (9 %cover), C. longifolia (3-10 %), C. brownii (9-21 %) and C. geminata (11-27 %), with C.simpliciuscula also being present (0-8 % Cover). Ecklonia radiata and a variety of smallthallose red algae, such as Laurencia filiformis and Anotrichium spp, were other predominantcomponents of the assemblage at Halfmoon Bay.Some species, incuding Ecklonia radiata and Caulerpa remotifolia at Ricketts Point werevariable in abundance over the three surveys (Figure 6.1). The largest changes inabundances observed between the three surveys were for Caulerpa geminata at bothRicketts Point and Halfmoon Bay (Figure 6.1). These changes are not considered biologicallysignificant but will be assessed more closely as more time-series data is collected.Abundances of Ecklonia radiata and Caulerpa remotifolia at Halfmoon Bay both appearedrelatively constant over the 3 surveys. E.radiata showing a slight increase and C. remotifoliashowing a slight decrease in abundance.35

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring30Ricketts PointEcklonia radiata30Halfmoon BayPercent C over201020100024Laurencia filiformis24Percent Cover1681680024Caulerpa remotifolia24Percent Cover1681680050Caulerpa geminata504040Percent C over30201030201002003 2004 2005 2006Year02003 2004 2005 2006YearFigure 6.1. Abundances of selected macroalgal species in the vicinity of Ricketts Point MarineSanctuary.36

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring6.3 InvertebratesThere were relatively few invertebrate species at Ricketts Point and Halfmoon Bay, with theassemblage structure being similar at both sites. The assemblages were dominated by veryhigh abundances of the sea urchin H. erythrogramma, with 900-960 per 200 m 2 at RickettsPoint and 480-550 per 200 m 2 at Halfmoon Bay. Other predominant species were blacklipabalone Haliotis rubra, biscuit star Tosia australis, eleven armed seastar Coscinasteriasmuricata and velvet star Petricia vernicina.Fewer common urchins Heliocidaris erythrogramma were observed at both sites during thethird survey, representing a decrease over the three periods (Figure 6.2). Similarly, Tosiaaustralis showed a decrease at Ricketts Point. There were no major changes in abundanceobserved for other species (Figure 6.3).The average blacklip abalone length at Ricketts Point increased from 77 mm to 92 mm, whilethe average length at Halfmoon Bay decreased from 88 mm to 85 mm (Figure 6.4).37

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring200Ricketts Point MSHaliotis rubra200Halfmoon Bay150150Abundance1005010050001200Heliocidaris erythrogramma1200Abundance8004008004000210Coscinasterias muricata21Abundance147147020Tosia australis0201515Abundance10510502003 2004 2005 2006Year02003 2004 2005 2006YearFigure 6.2 Abundances of selected invertebrate species in the vicinity of Ricketts Point MarineSanctuary.38

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring120Ricketts Point120Halfmoon Bay110110Length (mm)100908070602003 2004 2005 2006Time100908070602003 2004 2005 2006TimeFigure 6.3. Mean sizes (± 95% confidence intervals) of black lip abalone Haliotis rubra at RickettsPoint Marine Sanctuary and Halfmoon Bay reference site.6.4 FishesFish assemblages were more diverse, and larger species were more abundant, at RickettsPoint and Halfmoon Bay than at other sites in northern Port Phillip Bay. At both sites, the fishassemblage was numerically dominated by the southern hulafish Trachinopscaudimaculatus. During the first survey, transient species including a school of Australiansalmon Arripis trutta and several subadult male snapper Chrysophrys auratus were observedat Ricketts Point. Other prominent large species of fish included zebra fish Girella zebra,horseshoe leatherjacket Meuschenia hippocrepis and moonlighter Tilodon sexfasciatus.Species of leatherjacket included toothbrush leatherjacket Acanthaluteres vittiger, yellowtailed leatherjacket Meuschenia flavolineata and six spined leatherjacket Meuscheniafreycineti. There were lower abundances of fish at Halfmoon Bay than at Ricketts Point,although the assemblage was composed of similar species. Species at this site includedsnapper Crysophrys auratus, zebra fish Girella zebra, moonlighter Tilodon sexfasciatus,toothbrush leatherjacket Acanthaluteres vittiger and horseshoe leatherjacket Meuscheniahippocrepis.Both Trachinops caudimaculatus and Neoodax balteatus were variable in abundancebetween the three surveys. There was an increasing trend in Neoodax balteatus at HalfmoonBay, and a stong decreasing trend in trachinops caudimaculatus at Ricketts Point (Figure6.4).39

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringAbundance7006005004003002001000Ricketts Point MSHalfmoon BayTrachinops caudimaculatus700600500400300200100030Neoodax balteatus30Abundance2010201002003 2004 2005 2006Year02003 2004 2005 2006YearFigure 6.4. Abundances of southern hulafish Trachinops caudimaculatus and little rock whitingNeoodax balteatus in the vicinity of Ricketts Point Marine Sanctuary.40

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef Monitoring7. REFERENCESClarke K. R. (1993) Non-parametric multivariate analyses of changes in community structure.Australian Journal of Ecology 18: 117-143.Dayton P. K., Tegner M. J., Edwards P. B. and Riser K. L. (1998) Sliding baselines, ghosts,and reduced expectations in kelp forest communities. Ecological Applications 8: 309-322.Ebeling A. W., Laur D. R. and Rowley R. J. (1985) Severe storm disturbances and reversalof community structure in a southern California kelp forest. Marine Biology 84: 287-294.Edgar G. J. (1998) Impact on and recovery of subtidal reefs. In: Iron Barron Oil Spill, July1995: Long Term Environmental Impact and Recovery. Tasmanian Department of PrimaryIndustries and Environment, Hobart, pp273-293.Edgar G. J., Barrett N. S. (1997) Short term monitoring of biotic change in Tasmanian marinereserves. Journal of Experimental Marine Biology and Ecology 213: 261-279.Edgar G. J. and Barrett N. S. (1999) Effects of the declaration of marine reserves onTasmanian reef fishes, invertebrates and plants. Journal of Experimental Marine Biology andEcology 242: 107-144.Edgar G. J., Moverly J., Barrett N. S., Peters D., and Reed C. (1997) The conservationrelatedbenefits of a systematic marine biological sampling program: the Tasmanian reefbioregionalisation as a case study. Biological Conservation 79: 227-240.Edmunds M. and Hart S. (2003) Parks Victoria Standard Operating Procedure: BiologicalMonitoring of Subtidal Reefs. Parks Victoria Technical Series No. 9, Parks Victoria,Melbourne.Edmunds M., Hart S., Jenkins S. and Elias J. (2003a) Victorian Subtidal Reef MonitoringProgram – The reef biota at Wilsons Promontory Marine National Park. Parks VictoriaTechnical Series No. 6, Parks Victoria, Melbourne.Edmunds M, Hart S, Elias J and Power B (2003b) Port Phillip Bay Channels DeepeningEnvironmental Effects Statement – Marine Ecology Specialist Studies. Volume 6: ShallowReef Biota. Report to Port of Melbourne Corporation and Parsons Brinckerhoff. AustralianMarine Ecology Report 163, Melbourne, 139 pp.Edmunds E, Roob R. and Ferns L. (2000) Marine Biogeography of the Central Victoria andFlinders Bioregions – a Preliminary Analysis of Reef Flora and Fauna. In: L. W. Ferns and D.Hough (eds). Environmental Inventory of Victoria’s Marine Ecosystems Stage 3 (Volume 2).Parks, Flora and Fauna Division, Department of Natural Resources and Environment, EastMelbourne. Australia.Faith D., Minchin P. and Belbin L. (1987) Compositional dissimilarity as a robust measure ofecological distance. Vegetation 69: 57-68.Holling C. S. (1978) Adaptive Environmental Assessment and Management. Wiley,Chichester.Krebs C. J. (1999) Ecological Methodology, Second Edition. Benjamin/Cummings, MenloPark.Meredith C. (1997) Best Practice in Performance Reporting in Natural ResourceManagement. Department of Natural Resources and Environment, Melbourne.41

Parks Victoria Technical Series No. 28PPB Sanctuaries Subtidal Reef MonitoringRoob R., Edmunds M. and Ball D. (2000) Victorian Oil Spill Response Atlas: Biologicalresources. Macroalgal Communities in Central Victoria. Unpublished report to AustralianMarine Safety Authority, Australian Marine Ecology Report No. 19, Melbourne.H. Sweatman, D. Abdo, S. Burgess, A. Cheal, G. Coleman, S. Delean, M. Emslie, I. Miller,K. Osborne, W. Oxley, C. Page, A. Thompson. (2003) Long-term Monitoring of the GreatBarrier Reef. Status Report Number 6. Australian Institute of Marine Science, Townsville.8. ACKNOWLEDGEMENTSThis project was funded by Parks Victoria and supervised by Dr Anthony Boxshall.We are grateful for the field assistance of Jeff Giddins of Scuttlebut Scuba and FishingCharters.42