Research Project Summaries 2002-2009 - Marine Parks Authority ...

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This study highlights the variability in benthic assemblages on beaches, indicating thatlarge changes naturally occur in meiofaunal assemblages.MolluscsMolluscs are a diverse faunal group whose spatial patterns of diversity and communitycomposition were examined. There are currently 755 mollusc species identified withinthe marine park region (Rule et al 2007), with gastropods (excluding microshells) andbivalve molluscs accounting for around 600 species. These include many taxa thathave tropical (e.g. Harpa amouretta, Cypraea mauritiana) and temperate affinities(e.g. Cypraea piperita), with some at their southernmost extent (e.g. Tridacna maxima)(Smith in review). Several species had not previously been identified in the region,such as Mitra edentula, which was only known to occur on the southern Great BarrierReef (GBR) (Smith 2003).Mollusc assembladges (prosobranchs and bivalves) were surveyed on four nearshorereefs adjacent to Coffs Harbour (Smith et al 2006a). Species richness was highlyvariable between sites, even when separated by only hundreds of metres, and theoverall assemblage structure on these reefs was discrete (Smith and Harrison 2006).Comparisons between shallow rockpool assemblages at eight headlands also indicatedstrong variability (Birkbeck 2002).As part of a current PhD study, cross-shelf patterns of community structure weredescribed for subtidal molluscs in the marine park (Harrison unpubl. data). Two reefswere surveyed in each near-shore, mid-shelf and offshore region, with shelled molluscsmore than 5 mm long sampled at two sites on each reef, evaluating the effect ofseabed slope more than 45° and less than 45° on determining spatial assemblagepatterns. There was a clear difference in mollusc assemblages over the cross-shelfgradient but no significant difference between species richness and diversity. Slopehad no measurable effect on assemblage structure. Evaluating species responsible forthe patterns of assemblage structure indicated that offshore locations were dominatedby smaller grazing and predatory molluscs and sessile bivalves, especially Chama spp.Larger herbivorous molluscs, especially turbinids, increased in abundance at mid-shelflocations and dominated nearshore communities (Harrison et al 2006).AmphipodsThe biodiversity of amphipods in natural habitats and Artificial Substrata Units (ASUs)was examined, and taxonomic descriptions were developed for new species (Hughesand Lowry 2006, Hughes 2007). Initial surveys indicated that amphipod speciesrichness along a depth gradient (4–14 m) varied with exposure and location. At SplitSolitary Island, shallow depths supported the highest species richness, while at KorffsIslet, just south of the marine park, highest richness occurred at greater depths.Samples from 10 m deep, however, most often showed the highest species richness.Sampling using ASUs indicated distinct differences in assemblages between locations.Nine new species collected within the marine park during this study were described(Hughes and Lowry 2006). Other important taxonomic outcomes include the subgenusTelsosynopia (Karaman 1986) being given genus status; and reporting of Protohyalepusilla (Chevreux 1907) in Australia for the first time.Six types of ASUs were tested to develop a rapid assessment sampling packagespecifically to catalogue regional amphipod biodiversity (Hughes and Smith 2004). Foursites in the marine park were used to trial six ASU types, including new ‘scourers’successful in previous studies, and some untested scrubbers. Deployment was overtwo weeks, one month and four months, with one month proving optimum for bothabundance and number of species.10 Solitary Island and Jervis Bay Marine Parks Research Projects Summaries 2002–2009
Different types of ASUs supported different levels of species assemblages andcommunities. Unique recruitment to each type of ASU made each valuable todetermine regional amphipod biodiversity, with five types providing an optimum solution(Hughes 2007). Amphipods readily colonised ASUs, which sampled more amphipodfauna than the general collection of natural habitats. Assemblages recruiting to thesampling package were strongly representative of the local and regional species poolwhen compared to master lists compiled from all available records. While significantdifferences were found between types of ASUs, recruiting assemblages more closelyreflected location-specific differences when compared across the four island locations.Surrogates for biodiversityReliable indicator taxa need to be developed to assess effectiveness of marineconservation monitoring programs and management actions. Using the rocky shores ofthe marine park as a model, macroinvertebrates were evaluated to determine whichtaxa:best reflected ecological patterns of the broader intertidal communitywere able to accurately predict species richness of assemblages of entireheadlands (Smith 2005)Both molluscs and crustaceans showed high levels of correlation with overall speciesrichness. However, molluscs, particularly prosobranchs, most closely reflected patternsin community data and provided the most accurate predictions of species richness atthe headland scale. Molluscs offer considerable potential time savings, with reductionsin field time by up to 40%, as well as reduced need for extensive taxonomic knowledgeof other invertebrate groups. They are widespread and easily sampled, with stabletaxonomy and well-known ecology relative to other marine invertebrate taxa. Their useas surrogates of biodiversity has great potential for future marine conservation studies.To test this, surveys of death assemblages (dead shells) were conducted on 10headlands. Species lists were analysed to determine:average taxonomic distinctness – the degree to which species in a sample arerelatedvariation in taxonomic distinctness – the evenness of distribution of speciesacross higher taxonomic levelsThese biodiversity indices were then compared with equivalent measures determinedfrom a regional species list (Smith 2004).Five headlands returned average taxonomic distinctness. Progressive, random poolingof data further indicated that a species list compiled from any three or more headlandsfully represented regional biodiversity determined by this index In contrast, only threeheadlands showed variation in taxonomic distinctness, and progressive pooling acrossheadlands did not improve the outcome. This was mainly due to over-representation ofsome gastropod families, and under-representation of most bivalve families in deathassemblages at most sites. The practical implications are that at least three headlandsneed to be surveyed to obtain representative estimates of average taxonomicdistinctness of molluscs in the region. The unevenness of taxonomic representationand, in particular, the under-sampling of bivalves, further suggests that data collectedfrom paired headland–beach surveys may be more representative of regional molluscbiodiversity (Smith and Harrison 2006).In a further experiment, community structure was compared between two dominantnatural algal habitats (kelp holdfasts and algal turf) and ASUs (nests of pan scourers)Solitary Island and Jervis Bay Marine Parks Research Projects Summaries 2002–2009 11
Page 1 and 2: Solitary Islands andJervis Bay Mari
Page 3 and 4: ContentsSummaryiii1. Introduction 1
Page 5 and 6: SummaryBuilding a network of marine
Page 7 and 8: 1. IntroductionA network of marine
Page 9 and 10: 2. Biodiversity and ecological proc
Page 11 and 12: habitats outside the estuaries of t
Page 13 and 14: Reef fish assemblagesReef fish are
Page 15: To further examine the influence of
Page 19 and 20: noted that colonies of Turbinaria m
Page 21 and 22: Solitary Island and Jervis Bay Mari
Page 23 and 24: Figure 3. Study locations of three
Page 25 and 26: elatively short lifecycle (three to
Page 27 and 28: competition permit, had to submit d
Page 29 and 30: Sea turtlesSea turtles include vuln
Page 31 and 32: periodicity for acroporid corals. T
Page 33 and 34: 3.2.2 Population biology and assess
Page 35 and 36: Otolith microchemistry analysis of
Page 37 and 38: Assessing potential impacts associa
Page 39 and 40: y the MPA on reefs throughout the m
Page 41 and 42: Since the completion of this monito
Page 43 and 44: 6. Socio-economic influencesUnderst
Page 45 and 46: Figure 5. Hot spot analysis of over
Page 47 and 48: This study found that marine touris
Page 49 and 50: Visitor monitoring survey - NSW MPA
Page 51 and 52: Marine pests - University of Wollon
Page 53 and 54: Brown J (2000) Non-destructive asse
Page 55 and 56: Gladstone W (2007) Requirements for
Page 57 and 58: Lynch TP (2006), Incorporation of r
Page 59 and 60: Otway NM, Burke AL, Morrison NS, Pa
Page 61 and 62: Smart E (2000) An investigation int
Page 63 and 64: Wilkes K (2009) Boulder assemblages

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