Parks Victoria Technical Series No. 11 - Intertidal Reef Monitoring

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringExecutive SummaryIntertidal reefs support unique suites of species specially adapted to living under the constantinfluence of incoming and outgoing tides. Intertidal reef assemblages include largemacroalgal species, herbivorous and carnivorous invertebrates such as gastropods andseastars as well as many suspension feeding species. Biological communities on intertidalreefs are particularly susceptible to change and impacts caused by human activities becausethey are in close proximity to land-based activities and are easily accessible to visitors.In Victoria, a number of intertidal reefs are protected within a system of Marine NationalParks and Marine Sanctuaries. To effectively manage and conserve these important andbiologically rich habitats, the Victorian Government has established a long-term biologicalmonitoring program for intertidal reefs. Biological monitoring is done to characterisemacrobenthic intertidal reef communities, identify important spatial variation in populationsand communities across reefs, to determine the nature and magnitude of natural changes inspecies populations and communities over time and to detect impacts on speciespopulations and communities through comparison with appropriate reference sites.Intertidal reef monitoring at locations along Port Phillip Bay and central Victoria began in April2003. Locations ranged from Point Addis Marine National Park near Anglesea to MushroomReef Marine Sanctuary near Flinders.This report aims to:• provide general descriptions of the biological communities and species populations ateach monitoring site in April 2003ñJuly 2003,• identify any unusual biological phenomena such as interesting or unique communities orspecies, and• identify any introduced species at the monitoring locations.Quadrats positioned randomly within a 10 x 20 m survey area at each site were surveyed for:• mobile invertebrates, and• macroalgae and sessile (attached) invertebrates.Exploratory data analysis techniques were used to provide general descriptions andcomparisons of intertidal populations and communities in the Port Phillip Bay and centralVictorian coastal regions. Community structure, species diversity and species abundanceswere analysed.II

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringContentsExecutive Summary ............................................................................................................IIIndex of Figures and Tables ............................................................................................. VI1 Introduction .....................................................................................................................11.1 INTERTIDAL REEF ECOSYSTEMS OF VICTORIA ..................................................................11.2 INTERTIDAL REEF MONITORING PROGRAM.........................................................................22 Methods............................................................................................................................52.1 SURVEY SITES AND TIMES......................................................................................................52.2 CENSUS METHODS ................................................................................................................122.3 DATA ANALYSIS ......................................................................................................................193 Results ...........................................................................................................................213.1 MOBILE INVERTEBRATES (METHOD A) ...............................................................................213.2 SESSILE PLANTS AND ANIMALS (METHOD B) ....................................................................344 Discussion .....................................................................................................................42References.........................................................................................................................43Acknowledgements...........................................................................................................44V

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringIndex of Figures and TablesFIGURESFigure 1. An example plot depicting change in an environmental, population or communityvariable over time (days, months or years). ...................................................................3Figure 2. Parks Victoria Ranger, Dale Appleton, working with marine biologist duringintertidal reef monitoring surveys. ..................................................................................4Figure 3. Location of intertidal sampling sites in central Victoria and Port Phillip Bay. .........11Figure 4. Configuration of survey lines and tape measures for the geographic positioning ofrandom transects. ........................................................................................................13Figure 5. A marine biologist using tape-intersect measures to place quadrat on reef; and theìPocket PCî used to determined quadrat positions and record data.............................13Figure 6. Quadrat with the alga Hormosira banksii and snail Bembicium nanum. ................16Figure 7. Marine biologists counting invertebrates within quadrats during intertidal reefmonitoring surveys.......................................................................................................16Figure 8. Example of random quadrat positions for four sites. .............................................17Figure 9. MDS plot of intertidal invertebrate assemblages (Kruskall stress = 0.09)..............21Figure 10. Dominance-diversity curves for mobile invertebrates at each site. ......................26Figure 11. Box plots of common intertidal gastropod abundances (per 0.25 m 2 )..................28Figure 12. Size frequencies of limpet Cellana tramoserica shell length (mm). .....................30Figure 13. Size frequencies of gastropod Austrocochlea constricta shell length (mm). ........31Figure 14. Size frequencies of gastropod Bembicium nanum shell length (mm). .................32Figure 15. Examples of typical flora and fauna on intertidal reefs. .......................................33Figure 16. Box plots of seaweed abundances (% cover). ....................................................37Figure 17. Size frequencies of Neptuneís necklace Hormosira banksii frond length (mm). ..38Figure 18. Box plots of sessile animal abundances (% cover). ............................................39Figure 19. Example of spatial differences in abundances for selected species based onquadrat locations at Mushroom Reef (Site 2907). ........................................................40Figure 20. Example of spatial differences in abundances for selected species based onquadrat locations at Ricketts Point (Site 4111).............................................................41VI

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringTABLESTable 1. Intertidal reef monitoring sites in central Victoria and Port Phillip Bay. ...................10Table 2. Survey dates and start times for each intertidal survey site....................................11Table 3. Intertidal taxa censused during the first survey in the Port Phillip Bay and CentralVictoria regions............................................................................................................18Table 4. Mean abundances (per 0.25 m 2 ) of intertidal animals in the western region, PointAddis to Barwon Heads (n = 18). .................................................................................22Table 5. Mean abundances (per 0.25 m 2 ) of intertidal animals in the Port Phillip Bay region,Point Cooke to Flinders (n = 18). .................................................................................23Table 6. Diversity indices for pooled data for mobile invertebrates (n = 18) for each site. ....25Table 7. Mean abundances (% Cover) of sessile plants and animals in the western region,Point Addis to Barwon Heads (n = 18 quadrats). .........................................................35Table 8. Mean abundances (% Cover) of sessile plants and animals in the Port Phillip Bayregion (n = 18 quadrats)...............................................................................................36VII

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring1 Introduction1.1 INTERTIDAL REEF ECOSYSTEMS OF VICTORIARocky intertidal reefs are restricted to a narrow fringe between fully terrestrial environmentson land and fully submerged subtidal environments further offshore. Intertidal reefs in Victoriaare generally restricted to headlands and points and are often isolated from each other bystretches of sandy beach. Victorian intertidal reefs vary in structure from steep sloping rockfaces to relatively flat or gently sloping boulder fields and rock platforms. Weathering createsfeatures on intertidal reefs including cobble fields, vertical steps, undulations in the reef,crevices, patches of sand, and rock pools. The influence of the regular tidal cycle is the mostimportant determinant of the types of biota inhabiting rocky reefs. Intertidal reefs tend toexperience rapid changes and extremes in environmental conditions including temperature,salinity and exposure to air causing desiccation stress.Typical algal species on intertidal reefs include the mat forming brown algae Neptuneísnecklace Hormosira banksii and the green algae sea lettuce Ulva spp. Coralline algae andfilamentous brown algal turfs are also often present. Less conspicuous is a thin layer ofmicroscopic algae growing directly on the surface of the reef, which is an important foodsource for species of grazing molluscs.Molluscs tend to be the dominant faunal component on intertidal reefs. Herbivorous speciesinclude the limpets Cellana tramoserica and Siphonaria diemensis, as well as other speciessuch as Austrocochlea constricta and Bembicium nanum. Molluscan predators includeDicathais orbita and Lepsiella vinosa. The small mussel Xenostrobus pulex and tubewormssuch as Galeolaria caespitosa create encrusting mats on the surface of the reef. Otherinvertebrates on intertidal reefs include small crustaceans such as crabs and amphipods, aswell as sessile animals including anemones. Fishes move in over the reef as the tide risesand can be important structuring components of intertidal reef communities.Intertidal reefs are the most accessible component of marine environments and consequentlythese habitats have important social and cultural values. Intertidal reefs are sometimessubject to human pressures, including collection of animals for food and fishing bait,trampling and pollution from catchment discharges.1

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring1.2 INTERTIDAL REEF MONITORING PROGRAM1.2.1 ObjectivesAn important aspect in 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 can be usedto manage threats or pressures on the environment to ensure ecosystem sustainability.Consequently, the Victorian Government has established an Intertidal Reef MonitoringProgram (IRMP). The primary objective of the IRMP is to provide information on the status ofVictorian reef flora and fauna. This includes monitoring the nature and magnitude of trends inspecies abundances, species diversity and community structure. This will be achievedthrough a solid baseline of information and future surveys at locations throughout Victoria,encompassing both representative and unique habitats and communities.Information from the IRMP will allow managers to better understand and interpret long-termchanges in the population and community dynamics of Victoriaís reef flora and fauna. As alonger time series of data is collected, the IRMP will allow managers to:• compare changes in the status of species populations and biological communitiesbetween highly protected marine national parks and marine sanctuaries and otherVictorian reefs,• determine associations between species and between species and environmentalparameters (e.g., exposure, reef topography) and assess how these associations varythrough space and time,• provide benchmarks for assessing the effectiveness of management actions, inaccordance with international best practice for quality environmental managementsystems, 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.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 matchchanges in the real populations over time exactly or predict the size and nature of futurevariation definitively. 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). Furthermore, because the nature and magnitude ofenvironmental variation is different over different time scales, variation over long periods may2

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoringnot 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 NiÒo), 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 measured.ParameterTimeFigure 1. An example plot depicting change in an environmental, population orcommunity variable over time (days, months or years).The black circles denote examples of monitoring times. Note how data from these timesmay not necessarily reflect patterns over shorter time periods, or true maxima or minimaover 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 timeperiod.3

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring1.2.2 Monitoring Protocols and LocationsThe IRMP uses visual census methods developed prior to the survey and detailed in Section2.2. Following this first set of surveys, the method and data will be reviewed to provide adefinitive procedure for all future surveys, to ensure a consistent and comparable time-seriesof data can be maintained.The IRMP was initiated in April 2003 with 14 sites established on intertidal reef habitatswithin, and in the vicinity of, the following marine protected areas:• Point Addis Marine National Park• Point Danger Marine Sanctuary• Barwon Heads Marine Sanctuary• Point Cooke Marine Sanctuary• Jawbone Marine Sanctuary• Ricketts Point Marine Sanctuary• Mushroom Reef Marine SanctuaryFigure 2. Parks Victoria Ranger, Dale Appleton, working with marine biologist duringintertidal reef monitoring surveys.4

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring2 Methods2.1 SURVEY SITES AND TIMES2.1.1 Site EstablishmentIntertidal survey sites were established on intertidal reefs within seven marine protectedareas in the central Victoria and Port Phillip Bay regions:• Point Addis Marine National Park• Point Danger Marine Sanctuary• Barwon Heads Marine Sanctuary• Point Cooke Marine Sanctuary• Jawbone Marine Sanctuary• Ricketts Point Marine Sanctuary• Mushroom Reef Marine SanctuaryA reference site was established in association with each of these marine protected areas(Table 1; Figure 3). The date and time of commencement of each survey is given in Table 2.Each site was given a number in accordance with the Department of Sustainability andEnvironment database system for marine monitoring.At each reef, a site was established on the basis of:• large (10 x 20 m) area of relatively similar habitat (microhabitats) throughout andgenerally free of rock pools,• generally representative of the habitat(s) throughout that locality, and• accessible for a reasonable period at low tide.2.1.2 Site DescriptionsPoint Addis Marine National Park (Site 3109)The main intertidal reef at Point Addis is a large and prominent tongue of intertidal platformthat extends east from the base of cliffs northeast of Point Addis. This reef is long and isundulating in places. Large areas of this reef remain inundated during many tidal cycles andthis reef appears to be exposed to high wave action. The survey site is on a smaller patch ofreef that directly fringes the smaller coastal cliffs. It is a low-relief, uneven reef that dropsmore steeply at its edge to the subtidal zone. Undulations in the reef caused by weatheringcreate patches of standing water.5

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringThe intertidal reefs are exposed to the south and east. The Point Addis headland providessome protection from southwest winds and swell, although large waves from the southwestcan wrap around Point Addis onto these reefs.Winkipop (Site 3902)The intertidal area at Winkipop is a very low-relief, gently sloping reef. The area exposed atlow tide is between 30 to 50 m wide. This area is exposed to large southerly swell. Theintertidal reef however may be relatively sheltered from most of the wave energy because ofits gently sloping nature well out into the subtidal zone. There is a narrow band of sandybeach on the landward side of the reef. Undulations in the reef surface due to weatheringcreate patches of standing water. This reef may be periodically subject to some sandinundation.Winkipop is a reference site for Point Addis Marine National Park.Point Danger Marine Sanctuary (Site 4102)The intertidal area at Point Danger is a large sandstone reef platform that is an extension ofthe Point Danger headland. The reef is exposed to the north, east and south, however mostof the prevailing weather and waves are from the south and southwest. Most of the intertidalarea is relatively sheltered from large waves due to the large size of the platform. There arelarge areas of sandy beach to the west and north of the platform. Most of the reef is affectedby sand inundation, with a thin layer of sand being present in many quadrats. The survey siteis in the nearshore region of the platform.Point Danger Reference (Site 4101)Point Danger Reference is separated from the Point Danger intertidal platform by a shortsection of sandy beach. This intertidal area is a low-relief sandstone reef that has beenweathered to create an uneven surface at the scale of tens of centimetres. This reef has asoutherly aspect and is probably more exposed to waves than the Point Danger platform.This reef is subject to significant sand inundation because of its proximity to high energysandy beaches.Point Danger Reference is a reference site for Point Danger Marine Sanctuary.6

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringBarwon Bluff Marine Sanctuary (Site 4104)The intertidal reef at Barwon Bluff is composed of sections of sandstone and basalt reef. Theintertidal rock platform extends from the end of Barwon Bluff as a pincer-shaped reef. Thenortheastern section of the pincer is a basalt platform and boulder reef. This section of thereef is relatively protected from swell but has a large estuarine influence from the adjacentmouth of the Barwon River. The southwestern section of the pincer is a relatively flatsandstone reef, which is more exposed to large swells and sand inundation due to itsexposure towards the south and proximity to an adjacent surf beach and strong longshorecurrents. The survey site is on the sandstone section of the reef.Barwon Beach (Site 4103)To the west of the intertidal platform at Barwon Bluff there are several smaller isolatedpatches of intertidal sandstone reef. These reefs are directly exposed to large southerlyswells and sand inundation due to their proximity to the adjacent surf beach and stronglongshore currents. The reef surface has been weathered to create an uneven surface at thescale of tens of centimetres. The reference site for Barwon Bluff Marine Sanctuary ispositioned on one of these large isolated patches of reef.Point Cooke Marine Sanctuary (Site 4107)The intertidal area at Point Cooke is a relatively flat and extensive basalt rock platform andboulder field. Patches of sand and intertidal seagrass occur in some sections of the intertidalarea which extends from Point Cooke several hundred metres to the west. The survey sitewas positioned on the largest continuous area of reef to the west of Point Cooke.A suitable reference site, with intertidal habitat similar to that at Point Cooke could not befound. However, the intertidal areas at Altona and Williamstown will be used as referenceareas for Point Cooke Marine Sanctuary.Altona (Site 4108)The intertidal area at Altona consists of a basalt boulder field. The large basalt boulderscreate considerable structure in the reef by providing large areas of vertical rock face andcrevices. This intertidal area has an estuarine influence due to the proximity of KororoitCreek.The intertidal reef at Altona is a reference area for Jawbone Marine Sanctuary as well asPoint Cooke Marine Sanctuary.7

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringJawbone Marine Sanctuary (Site 4109)There is an extensive area of fractured basalt reef and boulder field at Jawbone MarineSanctuary. The reef forms a band up to 30 m wide and extends for several hundred metresfrom the point at Jawbone to the boundary of the sanctuary. The large basalt boulders createmedium to high relief intertidal reef with considerable structure due to the provision of largeareas of vertical faces and crevices. The intertidal reef at Jawbone Marine Sanctuary has alarge estuarine influence due to the proximity of Kororoit Creek and there is an area ofmangrove and saltmarsh habitat at the eastern end of the sanctuary. This area abuts aRAMSAR site and is an important habitat for migratory shorebirds.Williamstown (Site 4110)The intertidal area at Point Gellibrand, Williamstown is similar to Jawbone Marine Sanctuaryin being composed of a fractured basalt reef and boulder field. However, there is less verticalstructure and fewer crevices at Williamstown. The intertidal reef at Williamstown also has asouthwesterly aspect.The intertidal reef at Williamstown is a reference site for Jawbone Marine Sanctuary as wellas Point Cooke Marine Sanctuary.Ricketts Point Marine Sanctuary (Site 4111)The intertidal reef at Ricketts Point Marine Sanctuary is a low relief basalt rock platform.There are some relatively small isolated rock outcrops and patches of cobbles and smallboulders. The reef has a southwesterly aspect and can be subject to steep, short periodwaves during southwesterly storms. The survey site was positioned on the area of intertidalreef that is an extension of Ricketts Point itself.Halfmoon Bay (Site 4112)The intertidal area is less extensive at Halfmoon Bay than at Ricketts Point. At Halfmoon Baythere are areas of low-relief fractured basalt reef and cobble fields, as well as some intertidalseagrass. The reef has a southwesterly aspect. The survey site was located on low-relieffractured basalt reef north of the jetty at Halfmoon Bay.The intertidal reef at Halfmoon Bay is a reference site for Ricketts Point Marine Sanctuary.Mushroom Reef Marine Sanctuary (Site 2907)Mushroom Reef is a basalt intertidal reef that is in the shape of a mushroom when observedfrom the air. There is a large intertidal isthmus (the stem of the mushroom) that is composedof basalt pebbles and boulders. Sections of the isthmus tend to inundate with water soonafter the tide begins to rise. The head of the mushroom is low-relief but uneven basalt reefwith some pebbles and boulders. The highest section of the reef is the centre of the head of8

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoringthe mushroom. This area slopes away gently to the subtidal at its outer edge. MushroomReef is exposed on all sides, but is protected from large swell by shallow reef furtheroffshore. The survey site at Mushroom Reef was positioned at the south eastern side of thehead of the mushroom.West Flinders (Site 2908)The intertidal area at West Flinders is a low-relief gently sloping basalt reef with occasionalvertical steps and boulder outcrops. Patches of sand covered areas at the lowest reef extent.The intertidal reef at Flinders back beach has a southeasterly aspect and is moderatelysheltered from wind and waves from the southwest.West Flinders is a reference site for Mushroom Reef Marine Sanctuary.9

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring2.1.3 Survey TimesTable 1. Intertidal reef monitoring sites in central Victoria and Port Phillip Bay.Site Site Name A Position (MGA) B Position (MGA) Tape Dist OffsetEasting Northing Easting Northing X 1 X 2 X 1 X 23901 Point Addis 260118 5747082 260126 5747054 5 25 0 10(MNP)3902 Winkipop 262814 5749936 262804 5749912 5 25 0 104001 Pt Danger West 266069 5752994 266043 5752986 1 21 0 104002 Point Danger 266393 5753097 266387 5753065 9 29 0 10(MS)4003 Barwon West 280802 5759026 280785 5759036 5 25 0 104004 Barwon Heads 281279 5758946 281258 5758935 5 25 0 10(MS)4107 Pt Cooke (MS) 305905 5799930 305859 5799928 5 25 0 104108 Altona 310000 5806252 309978 5806240 5 25 0 104109 Jawbone (MS) 313144 5806988 313124 5807018 5 25 0 104110 Williamstown 315629 5806250 315616 5806232 3 23 0 1004111 Ricketts Point 326638 5793384 326615 5793400 5 25 0 10(MS)4112 Halfmoon Bay 325065 5795754 325051 5795768 5 20 0 102907 Mushroom (MS) 327106 5738441 327111 5738419 5 25 0 102908 West Flinders 326436 5739005 326420 5738985 5 25 0 10Marine National Park (MNP); Marine Sanctuary (MS).10

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringTable 2. Survey dates and start times for each intertidal survey site.Site Site Name Date Start Time3901 Point Addis 25-06-03 12033902 Winkipop 24-06-03 12034001 Pt Danger West 9-07-03 12004002 Point Danger 8-07-03 11114003 Barwon West 24-04-03 12264004 Barwon Heads 24-04-03 09304107 Pt Cooke 21-04-03 11194108 Altona 21/23-04-03 14214109 Jawbone 19-04-03 11034110 Williamstown 23-04-03 14004111 Ricketts Point 20-04-03 10454112 Halfmoon Bay 20-04-03 12502907 Mushroom Reef 25-04-03 09572908 West Flinders 25-04-03 12275810000Altona5800000Point Cooke410757900004108 4109 4110 41124111Ricketts PointMGA Northing (m)578000057700005760000GeelongBarwon RiverPort Phillip BayPoint Danger40024003 400457500004001Point Addis 390239015740000FlindersBass Strait2908 2907240000 250000 260000 270000 280000 290000 300000 310000 320000 330000MGA Easting (m)Figure 3. Location of intertidal sampling sites in central Victoria and Port Phillip Bay.11

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring2.2 CENSUS METHODS2.2.1 Standard Operational ProcedureA draft intertidal monitoring method was developed prior to the fieldwork. The objective ofthis method was to ensure quality and comparability of datasets between locations and overtime. The method will be reviewed following these surveys to produce a Standard OperatingProcedure for use in Victorian intertidal reefs.The method details a step-by-step process for field preparations, obtaining field data, postfieldprocedures for managing data and procedures for training scientific observers. It wasdesigned to minimise observer biases and error associated with visual census techniques, aswell as to comply with quality and occupational health and safety policies and procedures.2.2.2 Transect Layout and Quadrat PlacementAt each site, a base-line, 20ñ30 m long, was established along the shoreward margin of thesurvey area. Where possible, the line was placed between two distinctive features on thesubstratum, such as large boulders or rock outcrops. Global positioning coordinates weredetermined for the ends of the baseline: Position A on the left facing the sea; and Position Bon the right facing the sea (Figures 4 & 5).Two weighted measuring tapes were placed on the base-line, 20 m apart, and their positionsnoted (usually at 5 m and 25 m). The measuring tapes were denoted Tape A (lefthand,facing seaward) and Tape B (righthand, facing seaward).Software (IQPOS: Intertidal Quadrat Positioning System), running on a pocket personalcomputer, was used to determine random coordinates for quadrat placements (Figure 5).This software requires the UTM coordinates for positions A and B (northings and eastings forA and B), the positions of Tape A and Tape B on the baseline (X 1 and X 2 , normally set as 5,25) and the offset coordinates to define the down-shore sampling region (Y 1 and Y 2 , normallyset as 0, 10). The survey area was 20 x 10 m at all sites. The output of IQPOS included x, ypositions of each quadrat from the baseline, as well as tape-intersection distances and UTMcoordinates.The position of each quadrat in the survey area was then marked by a numbered weight,using the intersection coordinates for the two tape measures (Figures 4 & 5).12

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringY 220 x 10 m Survey Areayx, yTape ALengthTape BLengthY 1A N, EX 1 xX 2BaselineB N, EFigure 4. Configuration of survey lines and tape measures for the geographic positioningof random transects.The position of each quadrat was determined by the intersection distances of two tapemeasures extending from either end of a baseline.Figure 5. A marine biologist using tape-intersect measures to place quadrat on reef; andthe ìPocket PCî used to determined quadrat positions and record data.13

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring2.2.3 Method A ñ Mobile InvertebratesThe density of non-sessile invertebrates, such as gastropods and sea stars, was measuredby counting individuals within 0.5 x 0.5 m quadrats (Figures 6 & 7). The observer counted allobservable individuals on the rock surface or within crevices and algal fronds. To ensure themonitoring has minimal impact over time, rocks were not overturned or disturbed. Selectedspecimens were collected for identification and preservation in a reference collection.The shell length of 50ñ100 abundant gastropod species were measured at each site.Individuals were selected randomly by selecting the first ten individuals (of each species)encountered in or immediately adjacent to each quadrat. At the end of the quadrat sampling,additional size measurements were taken from all individuals within aggregations nearest tothe observer. Size measurements were taken for Bembicium nanum, Austrocochleaconstricta and Cellana tramoserica.2.2.4 Method B ñ Macroalgae and Sessile InvertebratesThe abundance of algae and highly aggregated sessile invertebrates, such as tubewormsand mussels, was measured as proportional cover of the substratum. This was done using apoints-intersection method. A 0.5 x 0.5 m quadrat was divided into a grid of 7 x 7perpendicular wires, giving 50 regularly spaced points (including one corner). Cover wasestimated by the number of points directly above each species (Figures 6 & 7). Selectedspecimens were collected for identification and preservation in a reference collection.Where Hormosira banksii was present, the maximum frond length of 50ñ100 plants wasmeasured at each site. Individuals are selected randomly by selecting the first tenencountered within each quadrat. At the end of the quadrat sampling, additional lengthmeasurements were taken by measuring all individuals in the patches nearest to theobserver.To ensure comparability with Fox et al. (2000), the presence-absence of selected specieswithin each quadrat was recorded (if not detected under any points). These species includedthe algae Ulva rigida, Cladophora subsimplex, Capreolia implexia, Ceramium flaccidum,Corallina officinalis, Hormosira banksii; and the tubeworm Boccardia proboscidea. Thesespecies are considered to be important for assessing ecological impacts at other locii on theVictorian coastline (Fox et al. 2000).14

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring2.2.5 Video/Photo QuadratsWhenever weather conditions permitted, a digital photograph was taken of the substratumand biota at each quadrat position. This was done to provide a permanent qualitative recordof the biota and microhabitat conditions.2.2.6 Qualitative ObservationsAt each site, observers made general observations of topography, reef structure (rugosity,relief, boulder sizes, etc.), biogenic habitat structure (Hormosira, algal turfs) and a generaldescription of the flora and fauna. Video and photographic records were also taken at eachsite.For each quadrat, the substratum microhabitats present were recorded. These wereclassified as:(h) horizontal surface, flat, rock top(p) rock pool(r) rocky rubble or cobble(s) sand(v) vertical surface, rock side, crevice (e.g., Figure 8)15

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringFigure 6. Quadrat with the alga Hormosira banksii and snail Bembicium nanum.The abundance of each gastropod is counted within the quadrat. The cover ofmacrophytes and highly aggregated animals is measured by the number of pointsintersecting each species on the quadrat grid.Figure 7. Marine biologists counting invertebrates within quadrats during intertidal reefmonitoring surveys.16

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoringrrrrrrrrrrrrrhhhr4107 Pt Cookerrhhhhhh h4108 Altonahhhhhhhhhhhhhhhhhhhphhh h hhhh4109 Jawbonehvhhhhhhhhhhhhhhhhhhhhhh4110 WilliamstownFigure 8. Example of random quadrat positions for four sites.Marks indicate 2 m intervals. Legend: (h) horizontal rock surface, flat; (p) rock pool; (r)rubble, cobble (v) vertical surface, crevice.17

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringTable 3. Intertidal taxa censused during the first survey in the Port Phillip Bay and CentralVictoria regions.Counts per Quadrat Counts per Quadrat Points CoverAnemones Limpets Blue-green AlgaeActinia tenebrosa Patella chapmanii RivulariaOulactis muscosaCellana tramosericaAulactinia veratra Patelloida latistrigata SeaweedsUnidentified anemone Patelloida alticostata Algal turfNotoacmea mayiEnteromorpha spp.Flatworms Notoacmea spp. Ulva spp.Unidentified platyhelminth Unidentified limpet EctocarpalesSiphonaria diemenensisHormosira banksiiBarnacles Siphonaria zelandica Thallose brown algaeChthamalus antennatusCorallina officinalisTetraclitella purpurascens Other Gastropods Gracilaria spp.Tesseropora rosea Austrocochlea constricta Thallose red algaeAustrocochlea odontisOther Crustaceans Turbo undulatus Sessile animalsUnidentified isopod Nerita atramentosa Galeolaria caespitosaUnidentified crab Bembicium nanum Boccardia proboscidiaNodilittorina unifasciataXenostrobus pulexChitonsPlaxiphora albidaUnidentified chitonDicathais orbitaLepsiella vinosaCominella lineolataOnchidella patelloidesBivalvesMytilus edulisSeastarsPatiriella exigua18

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring2.3 DATA ANALYSIS2.3.1 Analysis StrategyExploratory data analysis techniques were used to provide general descriptions andcomparisons of intertidal populations and communities in the Port Phillip Bay and centralVictorian coastal regions.2.3.2 Community StructureCommunity structure is a multivariate function of both the type of species present and theabundance of each species. The community structure between pairs of samples wascompared using the Bray-Curtis dissimilarity coefficient. This index compares the abundanceof each species between two samples to give a single value of the difference between thesamples, expressed as a percentage (Faith et al. 1987; Clarke 1993).Prior to analysis, the data were log transformed to reduce the weight given to highlyabundant species in describing community structure, giving a more even weighting betweenabundant and rarer species (following abundance transformations by Sweatman et al.,2000).The mulitvariate information in the dissimilarity matrix was simplified and depicted using nonmetricmultidimensional scaling (MDS; Clarke 1993). This ordination method finds therepresentation in fewer dimensions that best depicts the actual patterns in higherdimensions. The MDS results were then depicted graphically to show differences betweenthe replicates at each location. The distance between points on the MDS plot isrepresentative 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 Kruskal stress indicator is given by Clarke(1993): (< 0.1) is 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) is likely to yield plots which can be dangerous to interpret.2.3.3 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 each19

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoringspecies, 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 Simpsonís index(1/D Simpson = Hillís N 2 ). This index provides more weighting for common species, as opposedto the weighting of rarer species such as by the Shannon-Weiner Index (Krebs 1999). Theweighting of common species was considered more appropriate for this study, the samplingbeing directed more towards the enumeration of common species rather than rarer ones.The dominance-diversity structure of the distribution of individuals among species wasexamined more explicitly using k-dominance curves (Clarke 1990).2.3.4 Species PopulationsThe abundances of each species were summarised by calculating mean abundances foreach site. The variability in abundance between quadrats was examined visually using boxplots. The edges of box plots indicate the inter-quartile range and the medium is indicatedwithin the box. The whiskers on the boxes indicate values encompassing 1.5 times theinterquartile range, either side of the median. Outliers are indicated by circles.Examples of geographic differences in abundance within a site were given using bubbleplots.20

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring3 Results3.1 MOBILE INVERTEBRATES (METHOD A)3.1.1 Community StructureTwo predominant assemblage types of mobile intertidal invertebrates were identified: a PortPhillip Bay group, but including Mushroom Reef (cluster to left of Figure 9); and an opencoast group (cluster to right of Figure 9).The differences between these two groups were primarily because of a higher abundance ofthe limpets Patelloida alticostata, Notoacmea mayi and Siphonaria diemenensis and thegastropod Bembicium nanum at the coastal sites. In contrast, the limpet Cellana tramosericaand gastropod Austrocochlea constricta were more abundant in Port Phillip Bay (Tables 4 &5). Mushroom Reef (Site 2907) was similar to the Port Phillip Bay sites because of arelatively high abundance of Austrocochlea constricta, but had affinities with the other coastalsites, primarily in a relatively high abundance of Bembicium nanum (Table 5).Point Cooke (Site 4107) was the least similar to other sites in Port Phillip Bay, largelybecause it had markedly low densities of all species (Figure 9 & Table 6). Barwon HeadsWest (Site 4003) differed from the other coastal sites in having higher abundances of thebarnacle Tesseropora rosea, gastropod Nodolittorina unifasciata and small, unidentifiednotoacmeid limpets (Figure 9).S4002S4111S4108S2907S4112S4110S4109S3902S3901S2908 S4001S4004S4107S4003Figure 9. MDS plot of intertidal invertebrate assemblages (Kruskall stress = 0.09).21

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringTable 4. Mean abundances (per 0.25 m 2 ) of intertidal animals in the western region, PointAddis to Barwon Heads (n = 18).SpeciesSite3901 3902 4001 4002 4003 4004Actinia tenebrosa 0.44Oulactis muscosa 0.06 0.11Aulactinia veratra 0.17 0.06 0.44 1.50Unidentified anemone 0.06Unidentified platyhelminth 0.06Chthamalus antennatus 0.89Tetraclitella purpurascensTesseropora rosea 14.83Unidentified isopod 0.28Unidentified crab 0.11Plaxiphora albidaUnidentified chiton 0.06Patella chapmaniiCellana tramoserica 1.00 1.78 0.50 6.06 0.78Patelloida latistrigata 0.39Patelloida alticostata 1.11 0.22 0.39 0.78 1.28 0.50Notoacmea mayi 24.33 2.33 10.17 0.06 50.89Notoacmea spp. 25.72 0.11Unidentified limpet 0.06Austrocochlea constricta 0.17 1.61 0.06 0.28 0.11Austrocochlea odontis 0.06 0.11 0.06Turbo undulatus 0.17 0.17Nerita atramentosaBembicium nanum 6.17 4.89 7.33 15.11 1.50Nodilittorina unifasciata 12.67 90.83Dicathais orbita 0.06 0.06 0.17 0.56 0.17 0.44Lepsiella vinosa 0.06 0.22 0.11 1.61 0.1122

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringTable 4 (continued).SpeciesSite3901 3902 4001 4002 4003 4004Cominella lineolata 0.06 0.50 0.17 0.17 0.83Siphonaria diemenensis 32.11 17.78 21.39 0.78 26.17 53.39Siphonaria zelandica 2.39 8.11 11.94 0.28 3.11 4.61Onchidella patelloides 0.06 1.28Mytilus edulisPatiriella exigua 0.17Table 5. Mean abundances (per 0.25 m 2 ) of intertidal animals in the Port Phillip Bayregion, Point Cooke to Flinders (n = 18).SpeciesSite4107 4108 4109 4110 4111 4112 2907 2908Actinia tenebrosaOulactis muscosaAulactinia veratra 1.50 0.83Unidentified anemoneUnidentified platyhelminthChthamalus antennatus 0.06 0.06Tetraclitella purpurascens 0.06Tesseropora roseaUnidentified isopodUnidentified crabPlaxiphora albida 0.11Unidentified chiton 0.33Patella chapmanii 0.06Cellana tramoserica 3.50 12.44 10.61 0.11 8.89 1.00 0.50Patelloida latistrigataPatelloida alticostata 0.44 0.17Notoacmea mayiNotoacmea spp. 0.89Unidentified limpet 0.0623

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringTable 5 (continued).SpeciesSite4107 4108 4109 4110 4111 4112 2907 2908Austrocochlea constricta 3.39 27.67 5.06 6.11 42.56 3.44 25.06 0.22Austrocochlea odontisTurbo undulatus 0.50 0.06 0.06 0.83 0.06Nerita atramentosa 0.06 0.06 2.06 1.78Bembicium nanum 0.22 0.83 0.83 0.50 1.50 8.39 1.00Nodilittorina unifasciataDicathais orbita 0.06Lepsiella vinosa 0.17 0.17 0.06 0.39 0.39 0.94 1.00 0.61Cominella lineolata 0.17 0.06Siphonaria diemenensis 0.17 0.67 10.67Siphonaria zelandica 1.56Onchidella patelloides 0.06Mytilus edulis 1.33 0.06Patiriella exigua 0.33 0.063.1.2 Dominance and DiversityThe species richness of mobile invertebrates was generally lower within the Port Phillip Bayregion compared to the open coast. Most sites in Port Phillip Bay had 5ñ6 species over 18quadrats, except Jawbone and Halfmoon Bay, which had 10 species over 18 quadrats.Species richness on the open coast ranged from 9 to 16 species over 18 quadrats (Table 6).Differences in diversity and evenness did not reflect differences in species richness becauseof a high dominance of only a few species at some sites (Table 6). Diversity was more easilycompared using dominance-diversity plots (Figure 10). Diversity was lowest at Altona andRicketts Point (Sites 4108 & 4111), where most of the individuals in the community wereAustrochlea constricta (Figure 10 & Table 6). Jawbone and Williamstown (Sites 4109 &4110) also had relatively low diversity, with a numerical dominance of only two species:Cellana tramoserica and A. constricta. Sites with relatively higher species diversity (moresigmoidal-shaped dominance curve) were Point Danger and Point Danger West (Sites 4001& 4002), Point Cooke and Halfmoon Bay (Sites 4107 & 4112) and West Flinders (Site 2908;Figure 10).24

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringTable 6. Diversity indices for pooled data for mobile invertebrates (n = 18) for each site.Site Site Name N S N 2 E Simpson3901 Point Addis 1217 13 2.74 0.213902 Winkipop 658 14 3.23 0.234001 Pt Danger West 1219 16 4.97 0.314002 Point Danger 366 12 1.78 0.154003 Barwon West 3070 12 2.95 0.254004 Barwon Heads 2067 15 2.41 0.164107 Pt Cooke 124 5 3.01 0.604108 Altona 569 5 1.28 0.264109 Jawbone 344 10 2.01 0.204110 Williamstown 326 6 2.18 0.364111 Ricketts Point 788 6 1.06 0.184112 Halfmoon Bay 308 10 3.06 0.312907 Mushroom Reef 695 9 2.11 0.232908 West Flinders 315 12 2.52 0.21(N) pooled number of individuals; (S) number of species; (N 2 ) Hillís diversity index =reciprocal of Simpsonís Diversity; and (E Simpson ) Simpsonís Evenness.25

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringCumulative Abundance % Cumulative Abundance % Cumulative Abundance %Cumulative Abundance %100908070605040301009080706050403010090807060504030100908070605040301 101 101 101 10Species RankPt Addis3101 Pt Addis3102 WinkipopDanger/Barwon4001 Danger West4002 Pt Danger4003 Barwon West4004 Barwon HeadPort Phillip Bay4107 Pt Cooke4108 Altona4109 Jawbone4110 Williamstown4111 Ricketts4112 HalfmoonFlinders2907 Mushroom2908 West FlindersFigure 10. Dominance-diversity curves for mobile invertebrates at each site.Sites with curves to the lower left of the plot have higher diversity.26

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring3.1.3 Species PopulationsThe limpet Cellana tramoserica was most abundant at Barwon Heads West (Site 4003) andin the northern Port Phillip Bay region (Sites 4108, 4109, 4110 & 4112; Figures 12a & 15).Mean densities were above 3.5 per 0.25 m 2 at those sites (Tables 4 & 5). The highest sizefrequencieswere between 25 mm and 40 mm, with modes at most sites between 25ñ35 mmshell length (Figure 13). Very large individuals (> 40 mm) of C. tramoserica were observed atAltona and Jawbone (Sites 4108 & 4109; Figure 13). A cohort of smaller individuals wasapparent at both the Point Addis and Halfmoon Bay sites (Sites 3901 & 4112; Figure 12a).The limpet Patelloida alticostata was common on the western coastal sites, from Point Addisto Barwon Heads (Figure 12b). The densities were relatively low at these sites, averagedensities ranging between 0.4 and 1.3 per 0.25 m 2 (Table 4).The limpet Notoacmea mayi was only observed on the western coastal sites, with highabundances at Point Addis, Point Danger West and Barwon Heads (Sites 3901, 4001 &4004; Table 4; Figures 12c & 15).The gastropod Austrocochlea constricta was present at all sites surveyed except BarwonHeads West (Site 4002; Figure 12d). Densities were highest in the Port Phillip Bay region,particularly at Altona, Ricketts Point and Mushroom Reef (Sites 4108, 4111 & 2907; Table 6).The population size modes were variable between sites. Shell lengths were generally smallerat Winkipop, Altona, Ricketts Point and Mushroom Reef, with size modes of 12ñ20 mm shelllength. Shell lengths were particularly large at Point Cooke, with a substantial proportion ofshells at 24ñ28 mm (Figures 13 & 15).The gastropod Bembicium nanum was present at most sites but was most abundant at thecoastal sites. Highest abundances were at Point Addis, Winkipop, Point Danger West, PointDanger and Mushroom Reef (Figure 12e). Sizes were much larger at Point Cooke thananywhere else and two size cohorts (bimodal distribution) were apparent at Point DangerWest, Halfmoon Bay and Mushroom Reef (Figures 14 & 15).The pulmonate limpet Siphonaria diemenensis was only present on the coastal sites, withhigh abundances at Point Addis, Point Danger West, Barwon Head West and Barwon Head(Figures 12h & 15).27

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring30Abundance (per 0.25 m 2 )Abundance (per 0.25 m 2 )Abundance (per 0.25 m 2 )Abundance (per 0.25 m 2 )2010010864201208040080604020029072908390139024001400240034004410741084109411041114112290729083901390240014002400340044107410841094110411141122907290839013902400140024003400441074108410941104111411229072908390139024001400240034004Site410741084109411041114112a. C. tramosericab. P. alticostatac. N. mayid. A. constrictaFigure 11. Box plots of common intertidal gastropod abundances (per 0.25 m 2 ).28

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring40Abundance (per 0.25 m 2 )Abundance (per 0.25 m 2 )Abundance (per 0.25 m 2 )Abundance (per 0.25 m 2 )3020100108642054321010080604020Figure 11 (continued).029072908390139024001400240034004410741084109411041114112290729083901390240014002400340044107410841094110411141122907290839013902400140024003400441074108410941104111411229072908390139024001400240034004Site410741084109411041114112e. B. nanumf. L. vinosag. C. lineolatah. S. diemenensis29

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring403901 Pt Addis504108 Altona3040Count2010302010Count00 20 40 60604001 Danger West504030201000 20 40 60504002 Pt Danger4000 20 40 60404109 Jawbone30201000 20 40 60404110 Williamstown30Count302010201000 20 40 60504003 Barwon West4000 20 40 60504112 Halfmoon Bay40Count30203020101000 20 40 60Lenth (mm)00 20 40 60Lenth (mm)Figure 12. Size frequencies of limpet Cellana tramoserica shell length (mm).30

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring20153902 Winkipop6050404110 WilliamstownCount105302010CountCountCount00 10 20 30 40706050403020104107 Pt Cooke00 10 20 30 4080706050403020104108 Altona00 10 20 30 40704109 Jawbone60504030201000 10 20 30 40Lenth (mm)00 10 20 30 4050403020104111 Ricketts00 10 20 30 40403020104112 Halfmoon00 10 20 30 401002907 Mushroom90807060504030201000 10 20 30 40Lenth (mm)Figure 13. Size frequencies of gastropod Austrocochlea constricta shell length (mm).31

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring654001 Danger West154110 Williamstown410Count325100 5 10 15 20504002 Pt Danger00 5 10 15 20154112 Halfmoon40Count302010510Count00 5 10 15 2074107 Pt Cooke65432100 5 10 15 20Lenth (mm)00 5 10 15 20402907 Mushroom30201000 5 10 15 20Lenth (mm)Figure 14. Size frequencies of gastropod Bembicium nanum shell length (mm).32

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoringa) b)c) d)e) f)Figure 15. Examples of typical flora and fauna on intertidal reefs.The examples are (a) the green alga Hormosira banksii; (b) the common limpet Cellanatramoserica; (c) the limpets Siphonaria diemenensis (centre) and Notoacmea mayi; (d)the gastropods Bembicium nanum (bottom) and Austrocochlea constricta; (e) thegastropods Cominella lineolata (top) and Dicathais orbita; and (f) the anemone Aulactiniaveratra and the green alga Ulva spp. in standing water.33

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring3.2 SESSILE PLANTS AND ANIMALS (METHOD B)3.2.1 PlantsAlgal turf was mostly encountered at the edges of the survey areas, lower down the shore, oron reefs with a higher amount of standing water. This was particularly the case for the PointAddis and Barwon Heads sites, where the reefs surface was eroded into shallowdepressions that held water. Algal turfs were most abundant in area at Point Addis,Winkipop, Point Danger, Barown Head West and Barwon Head (Tables 7 & 8; Figure 16a).The green sea lettuce Ulva spp. only abundant at Point Cooke, where it was present in allquadrats (Figures 15 & 16b).The brown alga Neptuneís necklace Hormosira banksii was the most abundant seaweedencountered within the survey plots (Tables 7 & 8; Figure 15). Hormosira banksii was mostabundant at the coastal sites, particularly at Point Addis, Winkipop and Flinders West (Sites3901, 3902 & 2908; Tables 7 & 8). There was substantial variability between quadrats atthese sites (Figure 16c).The maximum frond lengths of Hormosira banksii were reasonably short at most sites, withsize frequency modes of 75ñ100 mm at Point Addis, Winkipop, Point Danger West, PointDanger and West Flinders (Figure 17). Point Addis, Point Danger and West Flindersappeared to have bimodal distributions, with a smaller cohort of 0ñ50 mm long plants.Barwon Heads West and Barwon West had predominantly small plants, with the dominantsize frequency modes at 75 and 25 mm respectively. Low numbers of large plants (150ñ200mm) were observed at Point Addis, Point Danger and West Flinders (Figure 17).Small turfs of the pink coralline alga Corallina officinalis were typically observed at the edgeof rock pools and other areas that remain relatively moist at low tide, such as in crevices.Corallina officinalis was observed at most sites in Port Phillip Bay but was most abundant inthe survey areas of Jawbone, Mushroom Reef and Flinders West (Figure 16d).34

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringTable 7. Mean abundances (% Cover) of sessile plants and animals in the westernregion, Point Addis to Barwon Heads (n = 18 quadrats).SpeciesSite3901 3902 4001 4002 4003 4004Blue-Green AlgaeRivularia spp.SeaweedsAlgal turf 13.3 3.0 0.6 6.2 29.3 32.2Enteromorpha spp. 1.0 0.2 1.1 0.4Ulva spp. 0.9Ectocarpales 1.0 1.2Hormosira banksii 25.7 63.7 15.8 19.1 11.0 17.7Thallose brown algae 0.8Corallina officinalis 0.1 0.9Gracilaria spp.Thallose red algaeSessile animalsGaleolaria caespitosa 1.0 1.1 2.2Boccardia proboscidiaXenostrobus pulex 25.2 13.2 0.4Sand 3.0 10.6 25.8 18.835

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringTable 8. Mean abundances (% Cover) of sessile plants and animals in the Port PhillipBay region (n = 18 quadrats).SpeciesSite4107 4108 4109 4110 4111 4112 2907 2908Blue-Green AlgaeRivularia spp. 0.9SeaweedsAlgal turf 1.9 0.2 0.4Enteromorpha spp. 0.9Ulva spp. 41.7 0.4 3.2Ectocarpales 2.4Hormosira banksii 0.3 25.8 8.0 44.0Thallose brown algaeCorallina officinalis 0.2 1.1 11.2 0.8 0.2 5.7 26.3Gracilaria spp. 6.6Thallose red algae 0.8Sessile animalsGaleolaria caespitosa 0.8 5.6 0.3 0.4 17.2Boccardia proboscidia 0.2Xenostrobus pulex 0.7Sand36

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring100Cover (%)Cover (%)Cover (%)Cover (%)806040200100806040200100806040200100806040290729083901390240014002400340044107410841094110411141122907290839013902400140024003400441074108410941104111411229072908390139024001400240034004410741084109411041114112a. Algal turfb. Ulvac. Hormosirad. Corallina20029072908390139024001400240034004Site410741084109411041114112Figure 16. Box plots of seaweed abundances (% cover).37

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring303901 Pt Addis204003 Barwon West2015Count10105Count00 50 100 150 200 250503902 Winkipop4030201000 50 100 150 200 250404004 Barwon Heads302010Count00 50 100 150 200 250354001 Danger West3025201510500 50 100 150 200 250304002 Pt Danger2000 50 100 150 200 25094110 Williamstown8765432100 50 100 150 200 250402908 West Flinders30Count20101000 50 100 150 200 250Frond Lenth (mm)00 50 100 150 200 250Frond Length (mm)Figure 17. Size frequencies of Neptuneís necklace Hormosira banksii frond length (mm).38

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring3.2.2 AnimalsThe predominant aggregations of sessile animals observed were of the calcareous tubewormGaleolaria caespitosa and small mussel Xenostrobus pulex. Small patches ofGaleolaria were observed predominantly at the Port Phillip Bay sites, with the highestabundance at Halfmoon Bay of approximately 17% cover (Tables 7 & 8; Figure 18a).Xenostrobus was only observed at four sites, with relatively high cover occurring at PointDanger West and Point Danger (Sites 4001 & 4002; Figure 18b).Evidence of the presence of the polychaete tube-worm Boccardia proboscidia was observedat Point Cooke (Site 4107; Table 8).60Cover (%)Cover (%)4020060402029072908390139024001400240034004410741084109411041114112a. Galeolariab. Xenostrobus029072908390139024001400240034004Site410741084109411041114112Figure 18. Box plots of sessile animal abundances (% cover).39

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringAustrocochlea constrictaBembicium nanumCellana tramosericaHormosira banksiiFigure 19. Example of spatial differences in abundances for selected species based onquadrat locations at Mushroom Reef (Site 2907).40

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringAustrocochlea constrictaBembicium nanumCellana tramosericaHormosira banksiiFigure 20. Example of spatial differences in abundances for selected species based onquadrat locations at Ricketts Point (Site 4111).41

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef Monitoring4 DiscussionThis survey provided the first systematic quantitative survey of both bayside and outer coastreefs in central Victoria, enabling comparisons between reefs at both small and large scales.Previous studies encompassing larger geographic areas were qualitative or semi-qualitative(e.g., Handreck & OíHara 1994), making it difficult to compare differences between locationsor between times. There has been a wealth of other intertidal studies in Victoria, but thesehave largely been restricted to a few locations and the measurement methods variedconsiderably between studies. A benefit of the techniques used in this study is that they maybe comparable with two other well established long-term intertidal monitoring programs:Boags Rocks outfall monitoring since 2001 (Fox et al. 2000); and Phillip Island outfallmonitoring since 1991 (Chidgey et al. 1995). The methods and their use will be reviewedfollowing this survey. Future surveys may use a modified method.Data from this survey provides a basis for the management of both the marine protectedareas and reefs outside these areas. This is through a description of existing conditions,enabling the identification of potentially important ecological aspects to be managed and thegeneral refinement and implementation of a long-term, systematic monitoring program.42

Parks Victoria Technical Series No. 11Central Vic & Port Phillip Bay Intertidal Reef MonitoringReferencesFox D., Jacoby C. and Molloy R. (2000). Eastern Treatment Plant: Monitoring the ReceivingEnvironment. Monitoring Program ñ 2001 to 2003. Report to the Melbourne WaterCorporation. CSIRO Environmental Projects Office, Melbourne.Chidgey S. S., Edmunds M. & Marshall P. (1995). Intertidal Biota at Phillip Island WastewaterOutlet, 1991, 1994 and 1995. Report to Westernport Region Water Authority. ConsultingEnvironmental Engineers, Melbourne.Clarke K. R. (1990). Comparison of Dominance Curves. Journal of Experimental MarineBiology and Ecology. 138, 143ñ157Clarke K. R. (1993). Non-parametric multivariate analyses of changes in communitystructure. Australian Journal of Ecology. 18, 117ñ143.Faith D., Minchin P. & Belbin L. (1987). Compositional dissimilarity as a robust measure ofecological distance. Vegetatio. 69, 57ñ68.Handreck C. P. and OíHara T. D. (1994). Occurrence of Selected Species of Intertidal andShallow Subtidal Invertebrates at Victorian Locations. Report to the Land ConservationCouncil. Marine Research Group, Melbourne.Sweatman H., Cheal A., Coleman G., Fitzpatrick B., Miller I., Ninio R., Osborne K., Page C.,Ryan D., Thompson A. and Tomkins P. (2000). Long-term Monitoring of the Great BarrierReef. Status Report Number 4. Australian Institute of Marine Science, Townsville.43

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.au